Exposure is not how dark or how light an image looks!

One of the issues with visiting the local library is that many of the books will have been based on film photography. While many of the concepts are the same, there are many things that are different.

In terms of artistic questions (framing, what to shoot, when to press the shutter, etc.) the concepts work equally well whether you are shooting digital or film. Modern technology can offer additional options, but the concepts are the same. For instance, if you are shooting sports, a book based on film photography might spend a lot of time on teaching you tricks to anticipate the exact moment to take the shot. You need to take into account shutter lag, and the fact that it may take a few seconds to advance the film and get a second shot. Many modern cameras can take five (or more) frames per second. It may not be important to spend time learning how to get the shot with only a single capture. Similarly, some books ill spend time on techniques to prefocus the lens, so you can get the shot just as the athlete hits a pre-determined spot. Many modern cameras have sophisticated auto-focus systems that can track a moving target, eliminating the need to pre-focus.

In terms of aperture affecting depth of field, shutter speed affecting motion blur, that's equally true for both film and digital. However a book built around 35mm film SLR cameras, may not mention that the values suggested in the book are only typical for that frame size.

But the real issue is exposure strategies. If your goal is maximizing image quality, than the strategies used for film are not the same that you should use for digital.

Consider a high key shot, with nothing darker than a mid tone (perhaps a polar bear in a snow storm). With a film camera, you will get a good result trusting the camera's metering system. This will give you an exposure where the narrow range of tones in your scene end up hitting the sweet spot in the middle of the negatives "S" shaped response curve. If you were shooting digital, you might want to use some positive exposure compensation in order to get that narrow range of tones as high as you can without blowing the important highlights.

The above is also true for a low key photo (perhaps a black dog on a pile of coal). With film, you trust the camera's metering, and with digital you would use positive exposure compensation.

Now if you were using an incident light meter, the strategies differ. With a high key shot and film, you would want a lower exposure than what the meter suggests. With a digital camera, the suggested exposure may be good.

With a low key shot and an incident light meter, you would want a higher exposure with film, and an even higher exposure for digital.

With film, the concern is generally the exposure of the midtones of the image. With digital the concern is usually with the exposure of the highlights.

Another issue is that books with a film heritage generally assume an "exposure centric workflow." You start by selecting the film speed you think is best for the scene, and everything revolves around hitting that exposure. If you want to stop down for more depth of field, they tell you that you must compensate by changing your shutter speed. With digital, that's not necessary, Digital has no requirement that you use the same exposure for every shot on the roll/memory card.

With digital, a good workflow is to select the largest aperture that yields sufficient depth of field, and the slowest shutter that doesn't yield unwanted motion blur. You then set the camera to Auto-ISO so you get a reasonable looking image from that exposure. That's a workflow that just isn't practical with film, and often isn't mentioned in any book that's based in film photography.

Interestingly, white balance remains a grey area.

That's why you need to browse thru the available material to find what fits your individual needs based on your desired application and level of experience. If you don't find exactly what you need, libraries often share resources and may be able to get something from another library.

Of course, you can always buy whatever books you think would be helpful. My natural inclination was to suggest a library because I've appreciated their usefulness so often in life and I hope they remain with us for a long time to come.

As a general observation, there are other ways to use a filter to maximize exposure. Consider a graduated neutral density filter. If you are shooting a scene with a bright sky and a darker landscape, you can use a graduated neutral density filter to try to normalize the brightness of the scene. by bringing down the sky, you can use a longer exposure to increase the light gathered in the darker landscape, without blowing out the highlights in the sky.

I know graduated neutral density filters are not perfect, and are not always the best solution, but there are times when then can be used for increasing the light gathered by the sensor.

Again, if you are getting good results without the filter, then it may not be worth the trouble to use it.

That's the word, tonality. Getting older, my brain's tonality is less dynamic.

With film or digital captures; visualizing, exposing, and processing to represent the full range of desired tones in the image — highlights, midtones, shadows, etc. — are key steps toward maximizing image quality. Care and concern needs to be paid to all of the elements you wish to preserve and express in order to capture and produce satisfying images.

Yeah, I think I meant the red and blue channels relative to one another, or relative to whatever a "properly" exposed red or blue color channel would be.

Do not assume you will get a good result. Do not trust your camera's metering system with any camera, film or digital. Your faith may be rewarded or it might not. Learn what metering options are offered; how each option responds to the range of light in your scene; the situations where a metering mode produces reliable readings; and the situations where it doesn't. Whether film or digital, cameras for decades have offered a variety of metering methods or options which vary depending on the individual model.

Some of the built-in metering options you can find among various film or digital cameras include: averaging, spot, partial (large spot), center-weighted, evaluative, matrix, etc. Understanding the differences in how these metering options measure, evaluate, and best suit the lighting conditions in your scene is important in getting good consistent results; regardless of the recording medium used.

It might, but I wouldn't count on it; unless you have a thorough understanding of your metering system and how to best utilize it in different situations.

You may need to use exposure compensation with a film camera as well. It's why film cameras with auto exposure systems often include some type of exposure compensation, auto exposure lock, or both.

I would not make those assumptions for the reasons already stated. Light meters function using the same principles regardless of the camera type. Light meters measure and make assumptions in their recommended or automated settings — the photographer needs to understand when and whether those assumptions will produce accurate results with the film or digital image captured.

"You may need to use exposure compensation with a film camera as well. It's why film cameras with auto exposure systems often include some type of exposure compensation, auto exposure lock, or both."

no not really, just got given an Olympus trip 35 which has auto exposure and if you need to add exposure compensation you just adjust the ASA :-)

[quote="@DonaldB"]

I occasionally used a Trip 35, which belonged to a sibling, when I first started to become interested in photography. Its a fun little camera which Olympus made for several years due to its popularity. I hope you will enjoy being the new owner of one!

I've owned a Minox 35 GT for many years which has a 2x "backlight switch" as its only form of auto exposure compensation. If anything else is needed, you have to turn the ASA dial to compensate like your Trip 35.

But, that's why I said: film cameras with auto exposure systems "often" include some type of exposure compensation, rather than always. Some, like the Trip 35, were bare-bones simplicity in their design and they can provide great enjoyment. Enjoy your Trip!

• I just saw a picture you posted of your Trip 35 and that you had loaded it with film. In case you're interested in some historical documents, here are links to: an Olympus Compact brochure; and one in color; and the 1968 dealer catalog pages from the U.S. Olympus importer at that time; all featuring the Trip 35. I had forgotten that one of its advertised selling points is that it locks the shutter release if the camera determines the light level is too low. Information in links is courtesy of the Pacific Rim Camera reference library which has a treasure trove of info on all kinds of old photo equipment.

Great clarification.

In my book, exposure means the light per area as well. If we refer to under- or over-exposed areas or images, this is relative to something we think should be right. Exposure is absolute. We can call images that seem too dark "under-exposed", because we think that they should be exposed brighter (i.e., more light on the subject, wider aperture or longer shutter speed). That's always just our personal judgement.

The only time where over-exposed could have an absolute meaning is when the sensor capacity is exceeded. Even then I'd speak of blown-out instead, and expose darker.

Yes I agree as well.

What is that "something" you are referring to?
If it is image lightness then you are changing the meaning of the word exposure to image lightness and not light per area when you say over/under exposed because you can keep the exposure* constant and make an image lighter or darker simply by adjusting ISO.

Image lightness and exposure* although related are two different things, not two different names for the same thing.

That doesn't really make much sense to me because after having set the optimal exposure** then if an image is still too dark it is not correct to say it is under exposed because no more exposure could have been added (unless adding light to the scene) because then the DOF and/or motion blur would have been messed up. In this scenario the image is too light, not under exposed.

* exposure - amount of light striking the sensor per unit area while the shutter is open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.

Yes. Meters are not a perfect solution. One should not blindly rely on them in all circumstances. However, they often work well enough to provide good results.

My discussion of how one might want to deviate from a meter's suggestion was a general discussion, and not a suggestion to blindly follow those rules of thumb,

I believe that it would be best to disconnect the terms over/under exposure from exposure and not take it literally. Overexposure should not mean too much exposure because it is almost never used that way. The same goes for other terms, e.g., shutter speed.

In what way is it an advantage (especially to a beginner) to encourage an incorrect use of the term?

Historically (in the days of film), Over/Under exposure did not refer to how dark or light the final print looked.

As to "Shutter Speed", that actually is a correct use of the word "Speed". "Speed" can refer to the rate at which something moves or operates. It can also refer to the duration a task takes. (for instance "That was a speedy trial"). It is reasonable to say that a shutter duration of 1/500 is faster than a shutter duration of 1/10 second. Even though in both cases the blades of the shutter move at the same rate. "Shutter Speed" refers to the duration the shutter is open. Shorter durations can legitimately be called faster speeds.

I do not feel that it has been agreed in this thread what the correct use of the terms over/under-exposure is. Exposure is any combination of aperture and shutter speed.

I believe it has been agreed that over/under exposure does not mean how dark or light the final print looks.