Jun 24, 2009 | Tech Tips
Reprinted from Vol 5-1 of the BT Journal
In wildlife photography, I think the psychology of color plays an overwhelming role in the success of an image to communicate. I’ve waited a long time to present this piece and I can’t think of a better time than with the Journal’s first color issue to bring you what I think are critical concepts for success.
Advertising-grabbing the attention of the buyer to buy one’s product. In a sense that’s exactly what we’re attempting to do with our photographs. To be successful we should be doing it with color in mind just like Madison Avenue! We might not be selling a “product” with our images, but we are most definitely aspiring to grab our viewer’s attention. And if our ultimate goal is to communicate, then we really are trying to sell something, even if it’s no more than our vision.
When I was in college, I took a class that was just about color in advertising. One of our assignments was to go to the supermarket, glance up and down all the aisles, without walking them, and take note of the most overwhelming colors we saw. Twenty years ago when I did that assignment, the overwhelming dominant color was red. If you were to do the same assignment today, you’d find that red is nowhere near the most dominant color anymore.
There’s an age-old adage that when photographing birds, if you don’t have a good background, find something green to put behind them. Why is the color green important or so pliable that it’s a universal cure-all for the backgrounds for birds? What is it about color that grabs our attention in a scene to photograph it in the first place? What are we doing technically right or wrong in our photography to exploit people’s natural draw to color? Unlock these answers for yourself and your photography will span the rainbow!
The Basic Psychology of Color
With the human brain able to distinguish over two hundred shades of white, able to see the same color no matter the light source, saying color is essential to our perception is no slight exaggeration. Viewing a black and white scenic full of all the shades of gray that a good paper and photographer can bring to light, the emotions just those shades of gray can evoke is tremendous! But that’s just a small sampling of the potential a full palette of colors can bring to a photograph. I’m not going to pass myself off as a scholarly master of psychology or try to convince you that one must have one color over the other for a photograph to be successful. A sunset is going to be in a red band of light no matter what psychological message we might want to communicate. What I want to bring to the forefront of your photographic consciousness and understanding is what color can communicate and how you can make use of that in your photography.
When photographing wildlife, you’d be surprised by the emotional response color can evoke, and how color, especially the color of the background, can emphasize and enhance that emotional response. We can’t change the color of a subject to any great degree, but we can definitely alter the colors of the world around the subject to some degree, using various technical tools at our disposal. (If nothing else, this will help you understand what images to send and not to send to editors.) But which colors communicate what? Let me give you some very basic descriptions of colors and how we subconsciously perceive them. (It’s very important to realize that we are talking about psychology of colors here; folks don’t see certain colors, then rationally think about their emotional response to them.)
Yellow – is the most visible color and is the first color the human eye notices! Yellow, the color nearest to “light” leaves a warm and satisfying impression, lively and stimulating and in many cultures symbolizes deity. Dark yellow can be oppressive while light yellow is breezy. Yellow’s stimulating nature and high visibility to the eye is the reason why many road signs are bold yellow (contrasted by black text). Yellow birds, flowers and skies are sure to be eye-catchers just because of the way the mind and eye works!
Orange – is a good balance between the passionate red and the “yellow of wisdom.” Orange is symbolic of endurance, strength and ambition. It can represent the fire and flame of the sun. Orange is said to also have the cheerful effect of yellow, but is intensified in its closeness to the color red.
Red – is a bold color that commands attention! Red gives the impression of seriousness and dignity, represents heat, fire and rage, it is known to escalate the body’s metabolism. Red can also signify passion and love. Red promotes excitement and action. It is a bold color that signifies danger, which is why it’s used on stop signs. Using too much red should be done with caution because of its domineering qualities. Red is the most powerful of colors.
Pink – is the most gender specific. Pink represents femininity and has a gentle nature (which is not a bad thing). Pink is associated with sweets like candy and bubble gum. It also symbolizes softness. Because it’s so “feminine,” use of pinks should be well planned. Pink and blue color combos are most associated with babies, soaps and detergents.
Purple – is a mixture of somber blue and active red. It can represent coolness, mist and shadows. It symbolizes royalty and dignity and can be mournful, yet soft and lonely. Purple is described as an “unquiet color” being mysterious and mystic in a cultural sort of way. A study revealed that purple, the color of mourning among many peoples, meets with disapproval in six Asian countries.
Blue – represents temperature, sky, water and ice. It is the second most powerful color. It obviously represents coolness, mist and shadows. In some applications it can represent peacefulness and calmness. And as pink represents femininity, blue represents masculinity. Blue is often associated with somber emotions like sadness, gloom and fear. Blue is a contemplative color, meaning intelligence and strength. It is one of the most politically correct colors there is with no negative connotations of it anywhere on the globe.
Green – is the most restful color for the human eye. It’s the universal color of nature as well as represents fertility, rebirth and freedom. (That answers the question why it’s the best background for birds.) Bright green can be uplifting while dark green evokes a mental picture of a pine forest. Street signs are painted a metallic green background contrasted with white letters because the combination is believed to be the easiest to read and recognize for the human brain. However, as with most colors, green also brings forth some negative connotations. The phrase “green with envy” also gives way to guilt, ghastliness, sickness and disease.
Brown – is associated with nature, trees and wood. It represents conservancy and humility. Next to gray, brown, in one of its many shades, is one of the most neutral of the colors. It is useful in balancing out stronger colors, and because it is one of the most predominant hues in nature, it gives a sense of familiarity. Light brown confers genuineness while dark brown is reminiscent of fine wood and leather.
Gray – gives the stamp of exclusivity. It’s the color “around which creative people are most creative.” Gray is a neutral color that can enhance and intensify any other color it surrounds. It can enhance the psychological response of the other colors it supports.
Black – is associated with elegance and class (black-tie affair). It is the traditional color of fear, death and mourning. Look at the many terms using the word black to understand how it is perceived: “black sheep,” “black heart,” “black and blue” and “black mark.” Despite the negative imagery that black brings, it is a preferred color in many designs since it contrasts with most colors quite well. If used correctly, it promotes distinction and clarity in your images.
White – symbolizes purity, innocence and birth. It’s closely associated with winter and can also represent surrender or truth. In the color spectrum, white is the union of all the colors. Its neutrality and conservative nature is widely accepted. Its simplicity and subtle quality makes it an ideal color for establishing clarity and contrast in your images.
If you’re like most folks, you’ve probably never thought about color in this way. That’s partly why it’s called the psychology of color. It is truly a powerful part of communicating, which is used on a daily basis in selling products. You’re probably saying this is all well and good, but what does it really have to do with your photography? Well why not use the same principles to help sell your message, your photograph or photography? I bet that if you look at your favorite photographs, whether your own or someone else’s, and you look at the colors and then read the above definitions, you’ll soon discover just how important color really is. Let me further demonstrate with some examples.
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The photo on the cover of this issue of the Journal of the male San Joaquin Kit Fox is a prime example. One of my signature images that has a huge publication history and has been used to help protect and preserve this endangered species for nearly fifteen years, grabs the viewers’ attention instantly. The dark background in concert with the fox’s posture brings out elegance and class. The brown coat is a color of familiarity and nature and with the slight orange tinge to the coat, brings warmth to the image. While these things are obvious in the photograph, the effects on the mental and emotional senses are not. It simply just grabs your heartstrings and doesn’t let go! Color is a big reason why!
Another good example of this is the photo of the Pacific Loon. This is as regal a pose as you can find, and as regal a bird as you can imagine! The early morning 5 am light of the tundra, the black body, white stripes and gray head are all dynamic colors. White and its purity, black with its elegance and gray with its depth make the loon stand out in the mind. But it’s the warmth of the yellowish gold background and foreground that give the image that “deity” feeling befitting the loon’s pose. Any other colors, and it would have been just a bird on the nest. But it’s the colors that make the image a standout and eye-grabber!
The critters in these two images and their poses are the heart of these images, but it’s the colors that make them stand out! Could I have put a different color background behind these two photos? Was there an option? Nope, it is what it is. My point is not that we can radically change background colors or even that of the subject to any degree, just that those really memorable images have color combinations like those in these two images that play on the psychology of the mind. We need to recognize this and exploit it, for lack of better terms, whenever it’s possible! It’s part of that eight second clock I’ve talked about before, that clock that starts when someone first looks at an image and the time we have to grab their attention before it goes elsewhere. Color psychology is a big part of beating that clock!
Tools for Color Psychology
Being aware, really aware of these colors and how they affect our perception and the responses they evoke inside of us is important. Understanding how you can affect these colors with the tools we use every day is even more important. I’m not talking about Photoshop or some bizarre filter, but basic tools you should have in your camera bag or vest at all times.
The lens and its angle of view as described in the last Journal is a very important tool. The ability to manipulate the background with large or small adjustments of lens positioning, depending on the focal length, can make a world of difference to an image. At the same time, your ability to get close physically to a subject and then use optics to isolate it can also make a difference. The Arctic Hare is a good example of what I’m talking about. By getting in close, I could eliminate the gray of the surrounding boulders and snow on the right and focus in on just the colors of the hare, emphasizing the warmth of the pelt and the effect of the setting sun on that pelt. Let’s be honest, who really wants to see a portrait of a bunny? But when there is drama and dignity in the color and light, it makes you stop and look, and hopefully wonder.
The film you use most definitely makes an overwhelming difference in your photography when it comes to the psychology of color! The bias of your film has the most obvious affect on the psychology of color. Everything from the qualities of its white to the richness of its greens and every shade in between, film is the platform from which you build your vision! The contrast of your film all by itself can make or break your communication efforts. Black is an amazingly important part of color, a separator, definer, and enhancer unparalleled! This critical fact that was driven home to me when I learned to do color seps for this Journal and saw how important it is just for editorial publication! All of this starts, and ends with your film so don’t take it lightly!
The very exposure you select for your photograph greatly influences its color and its mental effect. A mere plus or minus of just 1/3 stop can radically change everything! This effect on the subject, the background and surrounding colors, making them darker or lighter in tonality, all play such an important role in your ability to communicate. The image of the Roseate Spoonbill is an excellent example of this. The pink of the spoonbill is such a subtle yet dynamic color that can be radically changed by a mere 1/3 stop, be it from exposure or, and probably more importantly, the quality of the light. Look at the spoonbill; you can see detail in the shadow areas, which tells you the quality of the light that was present. You thought quality of light had to do with just exposure, but it greatly influences colors and their mental reach to communicate!
The psychology of color is the main reason why I always use an 81a filter. I’ve written about this before in the Journal, but this very simple tool that you can always have with you can make a world of difference in your success as a communicator and photographer!
Flash is another critical tool in the psychology of color. As you’ll read in other articles in this Journal, flash brings the film’s 5500k to light so the true color of the subject can be captured. There are times when, depending on the light source, this can be a critical part of making an image happen!
Even simple tools like the Polarizer can greatly affect the colors of your image. The importance of removing the blue, cold tint of the sky from a scene or subject can’t be overstated! That blue reflection, emanating from the sky can be an image killer! By combining the 81a and polarizer, you can radically change the mental perception of your photograph. Instead of repelling the viewer, you can suck them right in. It’s all in the psychology of color!
I more than understand that many will read this and say, phooey! There are definitely two camps in photography, the technocrats and the impressionists. While I personally feel both are important in the creation of an image, it’s the impressionist’s slant whose images I truly enjoy and in the business world, are the ones that sell.
Photography seems so much easier when all you worry about are f/stops and shutter speeds, but it’s one heck of a lot more fun when you consider thoughts way beyond those basics. Photography is a whole lot more rewarding when you take it to a higher plane, leaving behind the day-to-day drudgery and make it into a quest. And when you go beyond that and start taking into consideration such subtleties as the psychology of color when communicating, well the joy it brings to you and the viewer of your images cannot be expressed in words. When all the elements that make a great image come together, which must include the psychology of color, you’ll know it because the viewer of your image will simply smile, a smile that comes from deep within and radiates out, reflected in your photography!
The sun is rising on another great day, time to go out and capture some more images. Make it a colorful one!
Jun 24, 2009 | Tech Tips
What follows was written in spring, 2004. While the theory of TTL remains the same, in 2008 we’re in the iTTL world of the D3. For a more up to date explanation of using iTTL, you’ll want to head to the D3 site.
Flash is still the most difficult aspect of wildlife photography to master both technically and aesthetically. It doesn’t matter what camera you have, flash still takes plain old personal skill. Though this commentary can apply to any form of photography, I will as always focus in on wildlife photography (there I go with the bad puns). There a lot of theory being presented here, an exercise and basic concepts to aid in your mastering the flash. Remember this one very imprtant bit of advice. You learn flash only by doing flash. Reading what I have to say here will assist you in better understanding it, but you can only master it by doing it. So, on with the show! (Those shooting with the F5 should head directly to F5 Flash )
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Flash Basics
It doesn’t matter if you’re using Nikon or any other brand, flash basics are flash basics. The basics of manual flash and manual flash exposure must be understood even with today’s modern TTL technology! With the introduction of the N8008 and SB-24, it was said that those not knowing flash photography would become good and those knowing flash photography, would become great with its technology. True, the breakthrough technology of that system improved the mathematical percentage of technically correct exposed photographs. But the quality and creativity of flash photographs taken by the average photographer have not made the same quantum leap. This stems from the fact that basic flash exposure and technique has never been very well understood. This includes understanding all the advantages the Nikon flash system makes available to the photographer!
Before diving into this topic, one statement needs to be made about understanding flash photography. It takes time to master flash! Because it’s something we can’t see, understanding flash is a very, very difficult process. Don’t expect to comprehend all the theory and put flash into practice after first reading through this or any other explanation of flash. Give yourself and your equipment time to let it sink in. This book will have you up and running with flash, but it will still require some time before you’re using flash as a natural, unconscious photographic tool.
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Starting with Ambient Light
Understanding flash begins with ambient light. Flash is needed when ambient light is either too low, contrasty or nonexistent to properly expose the subject. Low light can come from shooting in the shade of a tree or late evening. Contrast seems to haunt our every exposure as we fight the battle between highlights and shadow. And no light for photography can be encountered in our own homes when shooting a birthday party. In any case, understanding these deficiencies is the first step in properly using flash.
The next step is understanding how we properly expose film for ambient light. Ambient light is the light that comes from the sun (99% of the time, artificial lighting such as from household lamps could be considered the other 1%) that bounces everywhere in and out of doors. To properly expose for ambient light, we have available to us shutter speeds and apertures. We must use the correct combination of shutter speed and aperture to properly expose film for the existing light based on the film’s ISO (film’s ISO to light index). A proper exposure in general terms is when detail can be seen in the highlights and shadows of a photograph. (If detail is not seen in either the highlight or shadows, then the range of exposure is beyond the ISO of the film.) The shutter speed and aperture each have a separate yet combined roll to play in proper exposure.
The shutter speed determines how long the film sees the light. Shutter speeds are described in terms of time. Current Nikon cameras have shutter speeds with durations of 1/8000 of a second to a full 30 seconds (this doesn’t include manual speeds/times fired using the bulb function). No matter how the shutter speed is set, whether manually dialed in or automatically derived via the camera’s computer, the shutter speed determines the length of time the film is exposed to the ambient light. The shutter speed also determines how long the film sees the subject. If the subject is not moving, the length of time the shutter is open and the film sees the subject does not matter. But if the subject is moving, long shutter speeds can result in out-of-focus subjects because movement is seen by the film.
The aperture regulates the amount of light that strikes the film. The aperture is a large hole normally at the rear of the lens through which light must travel to reach the film. It has blades that can be closed down, making the hole smaller, or opened up, making the hole larger. The larger the hole, the more light that can strike the film. The smaller the hole, the less amount of light that can strike the film. The size of this hole is described most commonly in f/stops (though not technically correct, but who cares as long as we all know what we’re talking about). The larger the hole, the smaller the f/stop number is. The smaller the hole, the larger the f/stop number is. For example, a large hole would have an f/stop of f/1.4 and a small hole an f/stop of f/32. The size of this hole also determines the depth-of-field in the photograph, that is, the depth of focus in front of and behind the subject.
These are our only two means of regulating the light that strikes the film. In flash work, it’s important to remember that shutter speed affects how long the light strikes the film and that aperture affects how much light strikes the film.
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Manual Flash Exposure Calculation
Understanding the above is relatively simple, but now is when it becomes more difficult! In the old days (less than a decade ago), flash exposure calculation was the cause of divorces. We all have those infamous holiday photographs when dad’s flash either made us white as ghosts or mere shadows against a wall. This was and still is, because of the lack of basic understanding of the two exposure regulators of the flash exposure. We have flash-to-subject distance and aperture as our only means of regulating manual flash exposure. We’ll start with flash-to-subject distance as it’s normally the hardest concept for folks to understand.
Flash-to-subject distance is just what it says, the physical distance between the flash and the subject. Even with TTL technology, this concept must be thoroughly understood! Back in the old days, this distance was generally determined by first focusing on the subject, and then reading the distance off the distance scale on the lens. Other methods such as a measured length of string, pacing off steps and even tape measures were used to determine this all important distance. This unit of measure was then put into a formula to calculate the needed aperture for proper exposure.
Generally, flash units would have a sliding scale on them for making this calculation easier. The table required the film’s ISO and flash-to-subject distance. With this, determining the needed aperture for correct exposure was made easy. Ha! And if you were really unlucky, your flash had no such table and a hand written, mathematical formula had to be used. This often required a piece of scratch paper and pencil, and lots of time. It also required knowing the flashes guide number and having excellent mathematical skill. But most importantly, it made flash photography extremely user unfriendly! It is also what made using flash so unpopular and dreaded, a sentiment carried by some still today! Since modern TTL flash technology, knowing or reading all these formulas is useless, lets cut to the chase and leap ahead to the more currently related flash problems.
The reason that flash exposure is determined by flash-to-subject distance is because of the power of the light emitted by the flash itself. The amount of light the flash bursts off is referred to as Guide Number, GN for short. The higher the number, the brighter the light emitted by the flash. The brighter the light, the further it can travel from the flash. But as the light travels from the flash towards the subject, the power or intensity of the light falls off. In fact, the light falls off at a tremendous rate called the inverse square law. This law says light from flash falls off at the rate inverse to the square of the distance the light has traveled. In plain language, flash units have really little power.
To illustrate this point, let’s look at the rate of light fall off for the SB-24/ 25/26 (which are all the same). Using film with an ISO of 125, a subject at 60 feet can be properly exposed at f/2.8. At f/4 it drops to 40 feet, f/5.6 to 30 feet, f/8 to 20 feet, f/11 to 15 feet, f/16 to 10 feet and at f/22 to a mere 7 feet. That’s an incredible drop off in power in the space of a few feet. But it’s important and a fact of life we must work with. (This assumes the subject is an 18% gray and does not take into account whether the subject is white or black because either case can radically change the needed f/stop.)
You should also note from this point the relationship between flash-to-subject distance and aperture. Aperture is our other means of regulating the exposure. Using the information in the above example, if the subject is 30 feet away the proper exposure is f/5.6. But if our subject is white and at that same distance, we would probably want to open the aperture up to f/4 to record the subject as white. And if the subject is dark, we would want to probably close up one stop to f/8. During this whole exercise, the flash-to-subject distance never changed. We changed exposure strictly by changing the f/stop.
The limitation with this is, what if we’re shooting a group of people at a distance of 30 feet? We should be using an f/stop of f/5.6, but that’s not enough depth-of-field to have the whole group in focus. And what if the group is a bunch of actors dressed in black costumes? The nightmares are just beginning for someone trying to accomplish this with manual flash. Yet thousands of situations like this were successfully taken with “old” flash technology because those photographers understood the basics of manual flash. But what does this have to do with modern TTL technology? Hold on, we’re getting there!
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Here Comes TTL
Nikon first introduced TTL (Through The Lens) flash technology in 1980. The basics of TTL operation is rather simple and applies to all camera systems. With TTL flash exposure, when the shutter is tripped, the light from the flash fires off, racing to hit the subject. This light hits the subject then bounces back to the camera. The light traveling the speed of light, travels through the lens (and any filters which may be attached) and strikes the film plane. The light then bounces down off the film to a sensor which reads the light as it builds up exposure on the film. Once the sensor and the connected computer software determines the light has massed enough for the correct exposure, the camera’s computer turns off the flash (just like a light switch in a house goes on-off). Keep in mind, this is all happening at the speed of light! Why is this technology so important to flash photography today?
Lets look back at the path of the light once it leaves the flash. The correct exposure for this equation was not determined by using either flash-to-subject distance or aperture. The correct exposure was achieved by simply turning off the flash! Whatever the size of the aperture, the hole the light must pass through on its way to the film, is dealt with by the camera’s computer at the film plane. Does this mean that flash-to-subject distance and aperture are not important to flash exposure? Not hardly, but it means we can control the flash rather than it controlling our photography.
With TTL technology, the camera’s computer provides the correct exposure regardless of the aperture or flash-to-subject distance (as long as they’re within the realm of the flash’s power). TTL technology puts the control of depth-of-field back into the hands of the photographer. We can pick the aperture for the desired depth-of-field and not have it preselected by the flash-to-subject distance. We can do this because the camera’s computer delivers the correct exposure for the aperture we’ve selected. If I’m going too fast and getting too excited for you to follow, let me explain it through an example.
Photographing nesting birds was, until TTL technology, a major pain. Large, bulky flash units had to be introduced into the home of the bird, often causing stress because of their size and presence. These large flashes were needed to light the nest sufficiently to obtain the desired depth-of-field. Because of their large size, these units had to be placed back from the nest and consequently had to have even more power because of the flash-to-subject distance. Then came the TTL flash units.
I remember this very scenario back in 1981 when I shot a nest with two SB-12 flash units and another photographer used two Norman 200b units. I stood four feet from the nest, had the two small flash units right beside the lens for the light pattern I wanted and most importantly, selected whatever f/stop I wanted for the depth-of-field I desired. I did this without any concern for the exposure as the camera’s computer did it all. The other photographer had to carefully place his flash units and use a flash meter to determine the correct f/stop. And once selected, he could not change that f/stop without moving his lights and thereby changing his flash-to-subject distance.
So TTL has taken all the calculations out of basic flash exposure. This is true for those who only want basic flash photographs. But I assume you bought this book because you want to take your flash photography beyond the basics by using flash as a creative tool. For this to happen, the melding of flash and ambient light is required.
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Flash Key vs. Flash Fill
Lets understand the terms. Flash key is where the light from the flash is the main light. Flash fill is when the light from the flash is filling in the deficiencies in the ambient light, in other words, filling in the shadows. The Nikon TTL flash system is more than capable of handling both of these situations without any help from us. But getting more than the standard canned light from the flash takes more from us. The specifics for programming the flash units will be covered under the appropriate sections. Here, I just want to discuss the concepts and techniques.
Flash Key
Flash key, like I said, is when the flash is the main light source for the photograph. This is not to say there is no ambient light, but that it’s not the major light source for the exposure. The main point to remember when the flash is the key light, it’s creating the light pattern for the photograph. This is a very important concept that will be discussed in greater depth later.
Exposure for flash key is normally a straight line affair (unless bouncing the flash). The TTL metering calculates the exposure based on what the light does bouncing off the subject. The light from the flash fires and shuts off, requiring the photographer only to remember to turn on the unit. When operated in this manor, the exposure for the ambient light will fall wherever it may, possibly influencing the final photograph or not. Generally, the only concern is the exposure of the flash.
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Flash Fill
Flash fill is used to fill in the shadows found in ambient light. This is a technique compacting the exposure range of the scene to fit within the latitude of the film. Most films can only hold information in the shadows and highlights when the range between the two is less than three stops. For example, if the exposure for the highlights is f/11 and the exposure for the shadows is f/5.6, the film will record detail in both. But if the exposure should be one stop more in either direction, the film will loose detail in the overexposed or underexposed area. The flash helps by pumping light into the shadows, decreasing the range and aiding the film in recording the detail.
Flash fill is described in terms of ratios. A 1:1 ratio means the light from the flash is equal to the light level of the ambient light. This means there are no shadows because the light from the flash wipes them out. A ratio of 1:2 means the flash is one stop less in exposure compared to that of the ambient light. In this case, there will be a shadow that is one stop less in exposure than the ambient light and well within the range of a film’s exposure latitude. The ratios keep going, 1:3, 1:4 and soon on, but after 1:4, the fill light is doing very little for your photograph.
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The Math of Flash Key and Fill
Taking flash to a higher level starts here! We must meld two light sources to really be successful in communicating photographically with flash. This requires understanding the two influencing factors of ambient light and flash.
Ambient light exposure is regulated by shutter speed and aperture. Flash exposure is regulated by flash-to-subject distance and aperture. The only variable in common for properly exposing the two light sources is aperture. This means that the aperture is the constant when melding the two light sources. The shutter speed must be changed to match up with the constant aperture (for proper flash exposure) to properly expose the ambient light. At the same time, the flash-to-subject distance must remain constant to provide the correct exposure for that aperture.
To further illustrate the point, let’s throw some numbers into the discussion. Using the SB-28 GN, we know that we must use an f/stop of f/5.6 when the subject is 30 feet from the flash. Our shutter speed must then match up with f/5.6 to properly expose the ambient light. As long as the flash stays 30 feet away, our aperture at f/5.6 and the shutter speed is correctly set, we’ll have beautifully exposed ambient and flash light. At least until the subject moves, the sun is blocked by a cloud or we need more depth-of-field. We are locked in to this formula when working with manual flashes if we want to properly expose ambient light and flash. But TTL gives us another option.
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The TTL Advantage
Because flash-to-subject distance doesn’t affect our f/stop with TTL (as along as we’re within the realm of the flash’s power), we can maximize and manipulate aperture and shutter speed to our advantage. In the instance of flash key, we can manually set the shutter speeds to correctly expose for the ambient light. We can also set the shutter speed to underexpose the ambient light. This can be as little as one stop to make a busy background disappear. Even in bright daylight, we can make the photograph have the appearance of being shot at night by underexposing two or three stops by using the shutter speed. This whole time, the flash is providing us with the proper exposure for the subject. We can do this only because TTL provides us with the proper exposure for the aperture selected regardless of the flash-to-subject distance! Wow!!
There’s a lot more to this than this simple explanation provides. But the specifics of how all this can be put into practice will be saved until actually talking about the specifics of the particular flash units. Just being aware of this and thinking about it though will help prepare you for those sections.
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The Shutter Speed Mystery
Many wonder why the shutter speed does not affect flash exposure. It’s simple, the shutter simply isn’t fast enough! The duration of the burst of light from the SB-24, 25, 26 and SB-28 ranges between 1/1000 to 1/23000 of a second. The light from the flash must be able to expose the film in one, solid burst to properly expose the film (this is not true with the FP feature on the F5, N90s/F90x). This means the shutter blades of the shutter must be completely out of the way when the light strikes the film or there will be a shadow on the film. Currently with Nikon’s focal plane shutters, a top shutter speed of 1/250 is available to sync with the flash. If a shutter speed of 1/500 or faster is used, a dark ban will be on the final photograph (the shadow of a shutter curtain). So why can’t the shutter control flash exposure, it’s simply not fast enough to freeze that burst of light!
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Can TTL Metering be Fooled?
You bet, even with the new flash matrix technology! The mechanics of how the new matrix technology works will be covered later. But be aware that the camera’s meters are still looking for 18% gray even in flash exposure. White or black subjects can throw the metering off and cause bad exposures. Size of the subject and placement in the frame can likewise cause exposure problems. The drawbacks with each flash unit and camera body when it comes to exposure will be covered under the appropriate sections. Just be aware that you, the photographer, still must be in charge and that all this technology is still only a tool and not the final word on exposure perfection!
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Conclusion
There’s a lot of material in this page on the theory of flash. Being successful in using flash means no one can see that flash was used in a photograph. This requires understanding the nuances of flash and ambient light exposure. There’s a lot more to learn in using the Nikon SB-24/ 25 / 26 / 28 that will aid you in this quest. There are a number of special effects that with knowledge of flash, can be programmed into the camera’s and flash’s computers that can take dramatic photographs without all the calculations. But to arrive at that point, understanding all the points made here is imperative!
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SB-24/25/26/28 Operation
Getting past theory and into using Nikon’s TTL flash system is an easy step. Nikon’s flagship flashes are the SB-24 (discontinued but owned by thousands) the SB-25 and current SB-26. These are TTL units with standard ISO shoes which fit the F4, N90 and N8008 series cameras. Using the two flash units on the respective bodies in practice is not that different, so the following operation information is generalized for all models.
The SB-24/25/26 can do all, part, or none of the flash exposure calculations for the photographer, depending on how it’s programmed. These flashes can also fill, mix or overpower (with limitations) the ambient light. The LCD panel on the back of the camera is where all settings are programmed to achieve this control. It’s where we’ll start to get a handle on the technological side of flash work.
The SB-24/25/26 are able to sync with the camera’s shutter in two ways: “NORMAL” and “REAR”. In “NORMAL” sync mode (selected by simply sliding the switch to the Normal position) the flash is fired the exact moment the last shutter blade of the first set opens the shutter. In this mode, the flash records the action the instant the shutter opens because it’s firing at that exact moment (remember the duration of the flash is faster than the shutter). When the F4/N90/N8008 are in Aperture priority and the flash is set to “NORMAL,” the only available shutter sync speeds are 1/60-1/250 (these are stepless speeds though). The N90/N90s and F5, this speed goes down to 1/20.
If the ambient light requires a shutter speed slower than 1/20, the camera underexposes the ambient light. In this mode, the camera is unable to go to 1/19 or slower shutter speed to correctly expose the ambient light. When working in dimly lit situations which require such low shutter speeds, switch the camera to manual mode (taking it out of aperture priority) and check the ambient exposure. If a slower shutter speed is required to properly expose the ambient light, manually dial in the shutter speed and shoot (stepless shutter speeds are lost when in manual mode). Or, switch the sync on the back of the flash to “REAR”.
In “REAR” sync mode, the flash fires the moment the first shutter blade starts closing the shutter after the ambient exposure is made (opposite of “NORMAL”). With the flash in this mode and the camera in Aperture priority, the camera can sync using stepless shutter speeds ranging from 30 seconds to 1/250. This is a tremendous range of exposure flexibility with TTL control!
Rear Curtain sync is a great feature, but it’s not where the flash should be permanently set. There are a number of reasons for this. Mainly, the photographer needs to be in control of what the flash is doing and in this mode, it’s easy to become complacent. There are many instances when a 30 second exposure wouldn’t work (such as nocturnal photography). There are times when the flash should be the key light and the shutter speed needs to be regulated. There will also be times when the fastest shutter speed possible is needed. For these and many more reasons, the flash should not be permanently set to “REAR” sync.
Understand these two modes and use them when the special application works the best for a given situation. For the majority of applications, the flash should be left in the “NORMAL” position. Switch it to “REAR” in those instances where it’s required, then switch it back to “NORMAL” when done. And whenever possible, take advantage of stepless shutter speeds by staying in Aperture priority.
The flash isn’t always used for fill-flash. For example, for night shooting when the flash is the only light, set it on “NORMAL”. Then set the camera on manual mode and set the shutter speed at 1/250. Since there is no ambient light to be properly exposing, use the fastest shutter speed possible. It speeds up the process, the motordrive goes faster, the shutter goes faster and everything else moves quicker. This gives that slight edge needed to get the photograph. It also insures the sharpest image possible when hand holding.
An obvious but none the less important switch is the Flash Mode Selector. There are four modes of flash operation with the SB-24/25: “A”, “M”, “Lightning Bolt” and “TTL”. The “A” makes use of the built-in flash sensor (not to be confused with TTL) for exposure. The “M” throws the photographer back to the days of manual flash, calculating flash-to-subject distance for proper exposure. The “Lightning Bolt” provides repeating flash operation, a strobographic effect which is more fun than practical. The “TTL” is where the flash should be set, taking advantage of its full potential.
Be aware of the distance scale on the LCD panel whether in “REAR”, “NORMAL” and “TTL” mode. When a lens with a CPU is in use, the distance scale and f/stop are displayed on the panel (this is true only when the flash head is set at the ninety degree position). The distance scale shows how close or far the subject can be from the flash with the f/stop selected (which is displayed). This is important information because beyond these distances, accurate TTL exposure cannot be made.
The SB-24/25/26 can be set for “Automatic Balanced Fill-Flash” and “Standard TTL” flash exposure. With Automatic Balanced Fill-Flash, the camera and flash computer are in complete control of fill-flash exposure. These will vary the flash exposure to equal the ambient light to underexposing the flash by minus 1 1/3 stop. The photographer never knows the amount of fill-flash used until the exposed film comes back from the lab and then it’s too late to see if the camera’s meter and computer figured correctly. With Standard TTL, the photographer is in complete control of the fill-flash, the way it should be.
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Programming the Flash
Photographers want to be in control of the Exposure. Accomplishing this requires programming information into the SB-24/25/26’s LCD panel. This can be a little tricky, so I want to go through the steps to clarify any holes in the instruction book.
To program Standard TTL on the SB-24, press the “M” button (not to be confused with “M” mode next to the “TTL”) causing the man/sun symbol to blink. On the SB-25/26, press the “M” button to make the man/sun symbol disappear. The flashes are now set to Standard TTL. The flash will now automatically expose the fill-flash to equal the exposure of the ambient light. In many instances, this is what’s needed (because of the subject’s absorption of light), but more often the flash is only needed to fill in the dead zones giving them more life. A little more programming is required to accomplish this.
With both units, press the “SEL” button to call up an analog scale which is where the amount of fill-flash is programmed. On the SB-24, press the up arrow to program minus compensation. On the SB-25/26, press the down arrow to program minus compensation. On both units, once compensation is dialed in, press the “SEL” to register the compensation or press nothing and after ten seconds, the compensation is automatically registered. Inside the camera’s viewfinder, the compensation warning will light when flash compensation has been programmed. The camera/flash computers will deliver the programmed amount every time the flash is fired.
This brings us to the question of how much fill-flash is the correct amount? Generally, I have my flash units programmed with minus 2/3 stop compensation. This is an amount that will clean up shadows and colors while not overpowering the quantity or quality of the ambient light. Keep in mind that dark subjects suck up light and light subjects bounce light back.
If there’s a doubt concerning just how the flash affects a subject, do a test. Apply the exposure compensation test to flash. Set up the teddy bears and shoot a test in various lighting conditions varying the flash compensation. Remember that we’ll all want a different amount of compensation according to individual personal taste in photographic exposure. The only way to find out that amount without the loss of good images is to test.
Ever seen a photograph of wildlife you know are out during the day but the photograph looks like it was taken at night? How about those images of wildlife taken during the day but the light is coming from different directions? My favorites are the over lit flash photos or those with five catch lights in the eye.
These are all mistakes in using flash that can be avoided and corrected. The black background comes from incorrectly exposing for the ambient light. The multi directional light comes from misunderstanding ambient light. Over lit derives from a lack of control of the flash exposure and multi catch lights are simply evidence of misplaced flash units. Provided throughout this book are the techniques to avoid these pitfalls.
SB-28 The really new thing about the SB-28 is its look. Besides being smaller, trimmer, it has an entirely new back panel, LCD display. The buttons are rubber coated and recessed on the SB-28, there are no longer any sliding MODE switches or the like. Even the On/Off switch is now a button so you can no longer accidentally change a function or turn on the flash. In fact, you must depress and hold down the On/Off button for a few seconds in order for the flash to come on. And the SB-28 will automatically go into Standby mode after approximate 80 seconds.
There are five basic modes possible with the SB-28 depending on the camera in use. There are no real surprises here, the instruction book pretty well lays things out. If you want to shoot in “standard” mode, you simply press the MODE button until just the TTL message is displayed in the top, left corner of the LCD. This puts you in control of the flash fill compensation as previously described.
There might be two “drawbacks” to the SB-28 depending on how you look at it. The first is it does not have Red-Eye reduction capability with the F5. As this is a feature I have never personally used, I don’t find this a drawback. The second drawback and more important to my own photography, is the smaller and dimmer AF illuminator. I don’t have a way of measuring how much dimmer it is, but it’s enough that I use the SB-25 for nocturnal shooting as my main flash, to take advantage of its AF illuminator.
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Special Compensation Technique
The unique capabilities of TTL technology can be taken one step further. With a firm grasp of flash compensation, use it in conjunction with the camera’s compensation. In situations where the flash is to be the key light and the background underexposed, the camera and flash computers can do it all, thus avoiding lengthy exposure computations.
In our example, we’ll assume we want the background (ambient light) underexposed by one full stop. The camera is set to Aperture priority, the metering set on Matrix. Dial in minus one stop via the exposure compensation on the body. This underexposes the ambient light by one stop; it also underexposes the flash by one stop. No problem because we’ll go to the flash and program it to overexpose by one stop. Now, the flash is the key light with no compensation.
If the subject is light colored and we want the flash to expose it to come out white, dial in no compensation or up to plus one stop. If it’s a dark subject, program in more than one stop plus compensation. Remember though that ambient light is underexposed and the flash is the key light, don’t make a mistake and underexpose the flash thinking its fill-flash. This is an excellent technique for making a distracting background disappear.
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Visualizing the Effect of Flash
It’s often difficult to judge the direction flash illumination will travel and its effect. When is the right time to take the flash off the camera? Previsualize by converting the flash to a flashlight. Point the imaginary flashlight at the subject and visualize the effect it will have. Where will the light strike the subject? Does it create a shadow and if so, where does the shadow fall around the subject? If there is a shadow on the subject that we want to make disappear using a flash, where should the flash be placed? Imagining the flash as a flashlight will help assess how the flash will effect the photograph.
Keep in mind that we want to imitate the sun and its effect when using flash. The key word here is imitate, not replace. The sun comes from above us, always. This means that shadows should always fall below subjects and not above them. So when using flash, shadows must appear below the subject and not above. There is also just one sun so there should only be one highlight reflected in the eye. With proper technique, multiple flash can be used while maintaining just one highlight.
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Off Camera Flash
The SB-24/25 can be taken off camera while maintaining full TTL connections via the SC-17 cord. This permits the flash to be placed anywhere around the camera up to three feet away. This provides all of the features of TTL flash and allows complete control of the flash’s light. Up to three SC-17 cords can be connected together creating a nine foot off camera cord. More than this creates too much resistance in the cord for all the TTL information to quickly communicate between flash and camera computers.
When attaching the SC-17, it’s recommended that it be attached to the camera body first, then the flash. The foot on the SC-17 where the flash is attached must have a flash attached to complete the cord’s circuit. Plugging an SC-18/19 cord into the foot of the SC-17 for a slaved flash without a “Master” flash attached to the foot will not work. The SC-17 has a 1/4-20 threaded socket on its base to allow attachment of the unit to a bracket or stand.
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Multiple TTL Flash
Nikon’s flash system is capable of controlling five TTL flash units. These flash units are linked together via the SC-17, SC-18 or SC-19 cords and the AS-10. The SC-18 cord is five feet long, the SC-19 is ten feet long. The AS-10 is required on all slaved units to complete the flash circuits (it attaches to the flash foot). The AS-10 also provides a 1/4-20 thread enabling the flash to be attached to a stand or bracket. The SC-17 foot and AS-10 provide TTL sockets for the SC-18/19. Use the sockets on the side of the flash rather than these.
Since the SC-18 and SC-19 are only three lead cords (five leads are required for full computer communication), as many as three SC-19s or six SC-18s (a total of 30 feet of extension in either case) can be coupled together for TTL operation. These cords are connected together via the AS-10 which doesn’t require a flash to complete the circuit. The SC-18 can be trimmed down (not recommended by Nikon) to accommodate any special brackets or applications thereby eliminating any excess cord from being in the way.
The SB-24/25/26 have two connections on their sides. One is a standard PC connection and the other is a TTL connection where the SC-18 and SC-19 cords are plugged in. When a TTL flash is used as a second light (slaved unit) via an SC-18 or SC-19 cord, all programmable functions on the second light are governed by the master flash connected to the camera’s hot shoe (whether on camera or attached via the SC-17 cord). The flash head Zoom function does work on the slaved units and should be manually set to match the master flash.
The SB-24/25/26 power switch has two modes, “STBY” and “ON”. Standby (“STBY”) saves on battery power and is a great feature for wildlife photographers. In general applications the flash is used for a period of time and then turned off. When the flash is needed over a long period but only sporadically fired, “STBY” is an excellent option. In this mode, the flash turns itself off after 60 seconds and comes on immediately when the shutter release button is pressed. (All slaved units must be set to “ON” and not “STBY” because they do not receive the impulse from the shutter release when pressed.)
Jun 24, 2009 | Tech Tips
Reprint from Shutterbug, September, 1995
With so much that has been written about exposure, the big question still remains for many. What is “the” perfect exposure? I want to add my two cents worth, in answering this question. I feel the answer lies more within ourselves than any exposure meter. I’ll try to lift what is for many, a tremendous burden – obtaining the perfect exposure for their photography!
I think understanding the answer can be found in the definition of the word perfect. Webster defines perfect as “to finish or complete, so as to leave nothing wanting.” It goes on further in defining the word by saying, “to make perfect or more nearly perfect according to a given standard, as by training or improvement.” These two definitions apply directly to photographers’ quest for “the” perfect exposure.
From my point of view, there should only be two criteria for the perfect exposure. First is how and what you want to communicate in your photograph (to finish or complete….). Second is what reproduces detail in either the print or printed page (to make perfect or more nearly perfect…).
Our Perfect Exposure
We tend to lose sight of what photography is really about – communicating. We don’t have brush strokes available to us to emphasize the subject. We can’t give rise with a crescendo to bring drama to our subject. We can’t even add the perfect adjective to better describe the subject. What we have to communicate with is light and how we expose for it.
Light is what gives life to our photograph, and exposing for it is what defines our own personal perfect exposure. For example, we can tell from a photograph whether it was taken on a sunny day or overcast day. We weren’t present at the time of the exposure, but the quality of light and how it was exposed clues us in as to the time it was taken. But was that what the photographer was trying to communicate or were they just following “the rules?” A sunny afternoon can be underexposed to darken the scene and an overcast day overexposed to brighten the scene. All of a sudden we have taken control of exposure making. We’ve now changed the scene to fit our desire, we’re now communicating by finding our perfect exposure.
There are a number of common situations that mess up the photographer’s mind when it pertains to exposure. The most common is snow. Oh my goodness, the number of letters I’ve received on how to expose for snow. The rule so often quoted is overexpose by at least one full stop. I hate rules! “You” have to decide what’s the subject and then expose for it. If the subject is the snow and you want to see detail in its crystals, then overexposure is called for. But if the snow is a mere element in the photograph, overexposure is probably not going to give you the perfect exposure for what you’re communicating.
Now this holds true for other light subjects as well as dark subjects. The white bird on blue water has to be the ultimate nightmare for the quest of the perfect exposure. But with my formula, it’s quite simple. If the white bird is the subject, then overexposure is right. If the white bird on the blue water is just an element, then overexposure is not needed. And when do you know which is correct? What is it you want to communicate?
This is why I’ve put this discussion of the perfect exposure first, because it is the most difficult. There are no rules to go by. There are no formulas in which you can attach to a scene to decide what it is you want to communicate. You, the photographer, the communicator, must make the decision on what it is you want to say. The disappointment many feel from their photographs when it comes to exposure is not from detail missing in the highlights or the shadows (to be discussed in a moment), but because it does not communicate what we wanted about the scene.
The Focal Encyclopedia of Photography, third edition says this about the perfect exposure, “The correct exposure for a photograph can be defined as an exposure that produces an image with the tonalities and colors the photographer desires,…”. In this pursuit of communicating, technical expertise in exposure is important. Don’t get me wrong, you must know what you are exposing for to communicate. But it is not the dominating factor, at least in my way of thinking, of the perfect exposure “….to leave nothing wanting.”
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The Technically Perfect Exposure
The math of the technically perfect exposure really isn’t that hard to spell out. Positive film (sorry, I can only speak for the film type I know, others differ), has generally an exposure range of 2 1/2 to 3 stops. This means that any highlights or shadows in the scene within this exposure range contains detail. But this very phrase might create confusion for you rather than clear things up, so let me elaborate.
A scene has a range of exposures for each and every element contained in it. The proper exposure for an element in a scene is when detail can be seen in that element, detail such as leaves, ruffles in a cloud. etc.. For example photographing a sunny scene (shutter speed for this example not relevant though would be constant for all), to expose for the highlights such as a cloud, an f/stop of f/16 might be required. Proper exposure for the shadows, the leaves at the bottom of a bush, might require an f/stop of f/5.6. If the highlights of the scene can be properly exposed at f/16 and the shadows at f/5.6, then they fall within the 2 1/2 stop range and detail is captured throughout the scene. In our photography we find this the exception and not the rule. (Obtaining the exposure for this scene can be derived in a number of ways and in itself is another article/book.)
Generally, the exposure range of our scene is greater than the range of the film. Depending where we place our exposure, either highlight or shadow detail is lost because it falls outside this range. This means that either highlights are burnt up, washed, or the shadows are blocked up, black, neither holding any detail. When this occurs, these photographs are referred to as “contrasty.”
In the quest for the perfect exposure, solving the technical side is easy to answer. Typically, we expose for the highlights and pump light into the shadows to bring them up within the magical 2 1/2 to 3 stop range. We have such tools as fill flash and reflectors to help fill in shadows. Their proper application when not detectable, lowers the exposure range of the scene so detail can be captured, while effectively communicating. (If you look closely at my photographs, you’ll notice that I typically let shadows go dark in scenics while with wildlife, there is shadow detail. That’s just my personal preference for the perfect exposure.)
Highlights can be tamed with polarizing and split graduated neutral density filters. These are generally applied to large scenes where the shadows are too large to be filled in. By exposing for the shadows, these filters hold back the highlights by underexposing them. In this way, they are brought within the range of the film’s exposure range. Now the polarizer will only do this when properly used to eliminate reflections and not just turned to create blue skies. (I tend to overexpose by 1/3 stop when using polarizers to bring up shadow detail just a tad.) The split graduated neutral density filter underexposes an area of the scene by as much 3 stops. This means a scene with a 6 stop range can be condensed to fit within the 2 1/2 to 3 stop range of the film.
Now means of metering to determine the proper exposure for various elements or scenes can vary. Preferences for exposing for the highlights or shadows can likewise vary, but the fact that we have this 2 1/2 to 3 stop range remains. The technical question of the perfect exposure lies within and outside this range. It is a question you can answer by simply applying the many tools available to us effecting exposure. Understanding where to base your exposure to capture this range can be accomplished by lots of trail and error, or doing my Teddy Bear Test.
Just to provide you food for thought, when you have a photograph where the highlights and shadows are within this range, you have the perfect exposure for prints or the printed page. I still contend this might not be the perfect exposure for the scene or what you want to communicate, but it will render the perfect print. This includes providing the ultimate in sharpness. There’s no doubt that sharpness of an image is at its greatest when the exposure is within this range “….according to a given standard… ”
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Obtaining Your Perfect Exposure
But you’re saying, “Moose, how do I know what I want or what happens when I apply a filter or underexpose?” Experience is still the best teacher because we all see differently and communicate differently, but I can provide you some insights as to what I do.
An example is shooting on overcast days. This to me is a magical time for photography. The exposure range is generally within the 2 1/2 to 3 stops without having to mess with flash or filters. Now if the scene has a definite mood to it, such as a stormy coastline or trees in fog, I expose as the meter advises. This generally underexposes the scene creating a darkened image. This creates a dark mood to the scene, communicating the mood I felt while making the exposure.
But I have found I can take this same overcast light and change everything by simply overexposing. Photographing in forests, or other normally contrasty places, are best when it’s overcast. But by exposing for the mood, the scene becomes very dark and gloomy. This is not what I want to communicate in many instances. So simply by overexposing by 1/3 to 1 stop, I can change the scene dramatically. How dramatic? You won’t even know by looking at the scene for example, that it was raining because it looks so bright. The thing that gives the technique away is that the highlights and shadows still hold detail.
Changing the exposure range to communicate what you want affects other elements in the photographic equation. Beware that for every action, there will be an opposite and equal reaction. By changing the exposure to obtain your perfect exposure, such things as contrast and color changes. Underexposing a scene generally saturates colors more where overexposure washes them out. The rich greens of a forest like the underexposure where the pastels of a field of flowers like the overexposure. And of course, the exact opposite might be what you like to capture.
So where have I led you in this discussion of the perfect exposure? Hopefully right back to where I wanted, to you. I want you to understand that the perfect exposure is what you like. You are the final judge as to what is perfect or not. You and only you know if what you saw in the scene is what you captured and communicated successfully. And you will know this not only from your own reaction to your image, but by the reactions of others. Anyone can master the technical side of exposure. Heck, most modern cameras can obtain the correct exposure for 90% of the scenes we encounter. But the real pro, master of one’s craft of communicating, must reach down deep inside to master one’s own perfect exposure. You won’t find the answer to the perfect exposure in my words, but only in your photographs.
