Overuse of the word 'Contrast'.

[Darin Cozine]

One thing that confused me when learning photography is the use of the word 'Contrast' It seems to be used for everything... scenes, lenses, film, developers, paper.

It really confused me in the context of film. Slide film was described as being high contrast compared to negative film. So I would think that it would be good for photographing a high-contrast scene. But in fact slide film can only capture a narrow band of contrast compared to negative film. So the end result looks more contrasty (damn I used that word again).

Wouldnt it be easier if we could use different vocabulary for each context??

[Thilo Schmid]

Darin, no, I don't think so, because the term actually applies to all these things somehow. "Contrast" is the difference between the darkest and the brightest parts of a picture, scene, lens-output, film-density, etc. Slide-film has got a high contrast, because the difference between the film base and Dmax can be as high as 4.0 logD (which is ~1000x "more" black than a print can be) and this has "nothing" to do with the scene contrast it is able to capture. So if the term applies to more than one aspect, there might be a confusion with the reference, but not with the meaning of the word.

[Frank Petronio]

"Contrast" used in commercial printing has a totally different meaning than photographer's "contrast", much to their dismay when proofing press sheets!

I agree, it is an overused term.

[John D Gerndt]

I agree with you about the use of the term. The only defense is to get a grip on the slippery slope of the technical facts of the photographic process. I have been working on it for 25 years.

If you can sort your way through the science of densitometry (and can afford the equipment!) you will be fine. If you are poor like me you’ll have to read a lot and sort through all the truths and half-truths to get to what is real and pertinent.

This forum has been a great source for (mostly) good information. Search the files and ask your remaining questions one at a time and I believe you will be quite happy with your results.

[Rob Tucher]

Contrast is a word like "criticism." There's negative criticism and positive, and many other types but people always complain of too much criticism as if it is only negative. I love criticism when it's positive and take negative criticism when I can learn from it. Contrast can be low, high, or anything in between, and what many people get confused by is that contrast defines levels of separation. More separation means lower contrast, more definition of tone. Lower contrast is fewer tones and less separation. And there's a lot in between this.

[Ted Harris]

If you want to learn more than you ever thought you wanted to know about terms such as resolution, constrast, sharpness, accutance, etc. ..... I highly recommend the book "The Critical Image"

[Ralph Barker]

I tend to equate the vocabulary of any industry with the "secret handshake" - you have to decipher what the terms mean within that context in order to be part of the crowd (club). ;-)

Contrast is one of the terms that can also take on slightly different meanings in various specific photographic contexts, as well. While generally referring to the difference in luminosity between bright and dark areas (the brightest and darkest, actually), and whether the graphical plot of that difference is steep (high) or shallow (low), there are subtle variations in usage that are not universally consistent between photographers. That seems particularly true when people speak of contrast with respect to lens performance. Thus, it is sometimes necessary to expand the discussion in order to disambiguate what the person means.

For example, while I think I might agree with Rob's explanation, I'm not completely clear on what he means by "separation", and would want to discuss that aspect further. Does he mean the total separation in luminosity between the brightest and darkest areas? Or, does he mean the ability to visually separate or differentiate between different, intermediate tones within a "continuous tone" image? (The latter, for me, being close to the definition of contrast when used to describe lens performance.)

[Darin Cozine]

Another thing that is hard to get my mind around:

When I print on VC paper and use a high-contrast filter, I get less tonal detail. But then Platinum and Azo printing, which has a higher contrast range, will yield better tonal detail. UG!

[Conrad Hoffman]

Learn what a paper or film curve (H&D curve) tells you about light coming in (log exposure) versus blackness (density). Contrast = Slope. A steep slope is a high contrast material and should be matched with a short tonal range input (also known as low contrast neg or scene). A mild slope = low contrast, and will match a high contrast neg or scene. Remember that both high and low contrast films and papers still go from black to white. Either one can produce a full tonal range if exposed to the correct range of neg or scene. If I say any more, I'll just confuse myself, but be assured that if you grasp what the curves are telling you, understanding contrast in any context will be trivial.

[Cesar Barreto]

Darin,

Sure, there's lot of abuse on this term and sometimes it can be so meaningful as the word "love" on politicians mouth. But it still can be clearly understood and I usually try the following approach on classes, classifying the different contrast meanings: 1- local and overall contrast - applied to subjet luminance, negative or paper densities 2- subject contrast - luminance range of the subject for itself 3- lightning contrast - wich adds to above 4- optical contrast - thought as 100% on ideal lenses and worse for many reasons wich depends on lens design, flare, misuse, etc.- 5- film contrast - depending on physical nature of particular emulsions (negative x positive film, for instance) 6- development contrast - a major issue on B&W 7- paper contrast - better understood as paper gradation.

What makes things a little harder to understand sometimes is the confusion among different beasts, such as exposure range and paper or film contrast. Both, slide films and short gradation papers (like using high VC filters), for instance, will need short exposure range to show it's full range of densities, or as people say, it's full contrast. Platinum paper needs long exponsure range (or contrasty films), like negative films welcome long scaled subjects (or contrasty subjects). Learning and understanding the whole lot of photo theoretical concepts really helps clearing the scene and our talking about it. And increase the contrast (!) of our seeing. Welcome to the jungle.