Telling difference between Overexposed/Overdeveloped and Underexposed/Underdeveloped...

[ryan_mcintosh]

This seems to be something alot of photographers do not know, well I

am one of those that fit into the group. How can you tell the

different between a under exposed negative and a under developed

negative? Same with a over exposed negative and a over developed

negative.

 

Reason I ask, is that I have abunch of film I been developing and

its coming out too dense. I dont know if it is because I am over

developing them, or over exposed them.

 

Thanks.

[daniel_smith6]

Rather than have it explained to you, why not do one simple test. Shoot a batch of negs with three rolls/sheets underexposed by two stops, three 'normal', and three overexposed by two stops.(or one roll each & then cut into thirds. Then one of each for half the indicated time, one for the 'normal' time and one for double the indicated time. Then, contact print each. This will give you negs so you can visually see what happens. Or, look at Horenstein B&W photo books & get some guidance.

[richard_cochran]

Yep, there's no substitute for looking for yourself.

<p>

But I'll give you a hint as to what to look for, anyway. Overdeveloping

increases density in midtones and highlights without increasing shadow

density. Overexposure increases density everywhere, including

shadows. Underdeveloping cuts highlight density way back, but leaves

shadow density. Underexposure cuts shadow density as well.

<p>

This is summed up in the photographer's proverb, "expose for

the shadows, develop for the highlights".

[jay_de_fehr]

I have read many a post suggesting that underdevelopment doesn't affect shadow density, but I do not believe that to be true. I've developed a fair bit of film by inspection, and I can tell you that the shadows are the last values to develop, and therefore significantly affected by underdevelopment. I think the confusion arises, at least in part from the maxim "expose for the shadows, develop for the highlights". It's true that a properly exposed negative, one in which adequate exposure was given to ensure the desired shadow detail, given development sufficient to render the highlight values in the desired tones, will represent approriate development. That is not meant to suggest that if that same negative was given insufficient development, that the low values would not be affected. In fact, the low values suffer the most from underdevelopment, which might often be mistaken for underexposure, as shadow detail is too often given as the sole indicator of proper exposure. It is for this reason that I recommend generous development for film speed tests. Overdevelopment will not increase a film's exposure threshold, but underdevelopment could result in a false reading. This is why high contrast scenes require more exposure than low contrast scenes. When development is reduced to control highlight values in high contrast (SBR) scenes, more exposure is required to prevent the low values from being underdeveloped. The scale is contracted from both ends; the highlights through decreased development, and the shadows through increased exposure. The inverse is true for low contrast (SBR) scenes, and illustrates why film speed and apropriate development are dependant on exposure conditions. So, by all means, expose for the shadows and develop for the highlights, but don't oversimplify the technique by suggesting that development doesn't affect low values, or exposure doesn't affect high values.

[andre_noble4]

An underexposed negative looks 'thin'.

 

An underdeveloped negative looks 'flat'.

 

One that's both looks hopeless.

[ryan_mcintosh]

Thank you.

 

The reason I ask is not because I want to judge my negatives I am doing now...but yet all my old 4x5 and 8x10 negatives vary alot, and while some are thin, and others really dense...I wanted to be able to know what went wrong. I have done tests, but I wanted to be able to look at a old negative and say "this negative is underdeveloped rather then under exposed"

 

I understand it now. thanks.

[peter_svensson]

Simple test: expose a flat wall at -4 stops exposure, then at +3 exposure. Develop. You should see a thin image in the -4 frame, which corresponds to zone I. If you see nothing, or it's very thin, you're underexposing.

 

Then use a light meter to measure the light coming through the zone I frame on a light table. Compare that to the light coming through the +3 exposure (Zone VIII). The difference should be about four stops (as recorded by the light meter, that is) if you're developing for a diffusion enlarger (corresponds to a density range of 1.2). If it's more, you're overdeveloping. If less, you're underdeveloping.

 

If you're developing for a condenser enlarger, a three-stop density range might be enough.

[lex_jenkins]

There's an excellent demonstration of the various degrees of exposure and development in "The Black and White Handbook" by Roger Hicks and Frances Schultz. Due to copyright restrictions I can't reproduce that page here. But you might find the book at a local library or bookstore.

 

Failing that there's a good example on Ed Buffaloe's excellent website, which should be on your list of most important bookmarks anyway.

 

http://unblinkingeye.com/Articles/Mortensen/mortensen.html

 

The examples are given within the context of an article about William Mortensen but are valid for any photographic situation.

[tim obrien]

I have read all of St. Ansels books, I have read the Zone System by Minor White, I have worked through most of BTZS and I still have no idea what Peter Svensson just wrote. *L*

 

tim in san jose

[donald_miller1]

I think that what Peter wrote makes perfect sense...I would look for 3 1/2 stops for a condensor enlarger and 4 stops for diffusion.

[avisualemotion]

Maybe it can be interesting to read in this thread. I had a simillar question there and get few good answers: <br>

<a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=006gt3">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=006gt3</a>

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richard vanek<br>

<a href="http://piskoftak.com/">http://piskoftak.com/</a>