Negative reading

VladimirC · May 5, 2011

Sorry for spamming the forum.

I am searching for some examples of how negatives look, in cases of overexposure, underexposure, underdevelopment... and so on.

I searched, found some things, but nothing satisfactory. Pretty hard to find it as digital image and be accurate (logical why) but if you have any quick resources on this I would appreciate.

dpurdy · May 5, 2011

There is an instrument made for measuring the density of negatives. It is called a densitometer. Otherwise negatives are generally judged from experience.
I actually have a known density patch taped to my light table for quick comparison of proper high density.
I do believe a negative should be beautiful to look at.
Dennis

puptent · May 5, 2011

You might look for Ansel Adams' The Negative, which is probably in your local library, and also available at amazon, hard cover and paper back, ands used book stores, (which is where I found mine).

Gerald C Koch · May 5, 2011

If one is considering exposure and development then there are nine possible combinations ranging from underexposed and underdeveloped to overexposed and overdeveloped. Some books on photography will picture a matrix of these nine combinations and can be very useeful in training the eye.

The size of a negative really determines how easy it is to read it. LF is the easiest and there are a couple of useful tricks. First, place the negative on a newspaper. If the print can be easily read then the density is correct. The second test for contrast is a bit more involved. One must first determine the contrast looking through the negative at a piece of white paper. Next the negative is placed on the paper and evaluated again. If the contrast appears OK in the first case and too much in the second then the negative is correctly developed. Conversely if the contrast is too low in the first case but appears to be correct in the second then the negative is underdeveloped. The reason that this test works is that light must pass through the negative twice in the second case and this enhances its appparent contrast.

Doremus Scudder · May 5, 2011

A quick Google search turned up the following. Maybe it will help:

http://www.olympusmicro.com/primer/photomicrography/bwprocessingerrors.html

Best,

Doremus Scudder

www.DoremusScudder.com

VladimirC · May 5, 2011

Guys, I have read Ansel Adams books and know what a densitometer is . I need only pictures like in the ones mentioned by Doremus. I don't need lg's, fb-f's or accurate measurements.

Gerald: thanks for the newspaper tip, great to know it. I need exactly pictures with the matrix you are talking about .

I also found on google some, but I need more examples, I'm hoping you have some good sources.

ic-racer · May 5, 2011

After looking at negatives for almost 30 years I'd summarize the following:

Under exposure: usually easy to tell
Over exposure: very, very difficult tell if a negative is unprintable because looking for good separation in the very dark portions of the negative is almost impossible as the human eye can be 'blinded' by the lighter areas.
Over Development: usually easy to tell. The negative looks very vivid with a density range identical to the original scene, almost like a slide or transparency. Realize that a properly developed negative will have LESS overall contrast than the original scene by about six to seven tenths.
Under development: can sometimes be very hard to tell from under exposure.

The best way to analyze pictoral negatives is to try and print them. Using a denstometer on a pictoral image is difficult even with 8x10. On one of my typical 8x10 negatives there are very few areas that are uniform and more than 3mm in diameter to make a reasonable reading with the densitometer probe. If you are doing ULF, then the arm of the densitometer won't reach to the center of the negative. Using the denstiometer for rollfilm negatives is usually only reliable when filling about 5mm of the frame with a known uniform area of illumination.

jp498 · May 5, 2011

ic-racer said:
After looking at negatives for almost 30 years I'd summarize the following:

Under exposure: usually easy to tell
Over exposure: very, very difficult tell if a negative is unprintable because looking for good separation in the very dark portions of the negative is almost impossible as the human eye can be 'blinded' by the lighter areas.
Over Development: usually easy to tell. The negative looks very vivid with a density range identical to the original scene, almost like a slide or transparency. Realize that a properly developed negative will have LESS overall contrast than the original scene by about six to seven tenths.
Under development: can sometimes be very hard to tell from under exposure.

This is basically what I observe as well.

Underexposure/Underdevelopment is observed as thin/weak looking highlights which turn into a lack of shadow detail in the print.

Underdevelopment is almost the same as underexposure, except sometimes you can see the factory printing on the edge of the negative isn't as developed as it should be. Sometimes streaks are visible if you're WAY off like testing a new developer/process.

MattKing · May 5, 2011

This article on "Assessing Negatives" is handy:

http://www.ephotozine.com/article/assessing-negatives-4682

brian steinberger · May 8, 2011

How reliable is the "reading a newspaper through a negative" theory? I have plenty of negatives that print great but I cannot read a newspaper through them.

Gerald C Koch · May 8, 2011

I came into the possession of several 8x10 glass plate negatives circa 1930. What immediately struck me was how thin they appeared yet they produce beautiful prints. You can easily read a newspaper through them. Years ago photographers tried to produce the thinnest possible negatives that still had good shadow detail. Remember papers at that time were very slow. Excess density only contributes to increased graininess.

brian steinberger · May 8, 2011

Gerald C Koch said:
Years ago photographers tried to produce the thinnest possible negatives that still had good shadow detail.

Is this still the case?

srmcnamara · May 9, 2011

It surely depends on your own way of printing combined with your initial and final visions for your print. I find the one mistake I make more often than any other is overdevelopment. So, when I see a negative I look first and foremost for highlights that are not too strong. If this is the case, I usually have no trouble with the print.

brian steinberger · May 9, 2011

I guess the problem I have is viewing a negative on the light table vs. against a white piece of paper. My negatives look great on the light table but against a white piece of paper on a table they look very dense overall, but do print ok. Maybe I should try cutting my development time back a bit, 10%.

2F/2F · May 9, 2011

VladimirC said:
Sorry for spamming the forum.

I am searching for some examples of how negatives look, in cases of overexposure, underexposure, underdevelopment... and so on.

I searched, found some things, but nothing satisfactory. Pretty hard to find it as digital image and be accurate (logical why) but if you have any quick resources on this I would appreciate.

You'll see examples in any basic photo textbook. There should be several at your nearest library or book store.

2F/2F · May 9, 2011

brian steinberger said:
Is this still the case?

Not so much. Our films can handle overexposure much better (i.e without getting super grainy and having the tonality significantly tweaked), and many people now advocate overexposing negatives as a matter of course. I am not one of them, but I understand the technical and artistic reasons behind the practice, and in some situations, I will overexpose a lot in order to get what I want. But generally, I prefer not to load a negative with density and detail that I do not plan on using.

PVia · May 9, 2011

2F/2F said:
You'll see examples in any basic photo textbook. There should be several at your nearest library or book store.

Replies #6 and 10 have some example links.

Gerald C Koch · May 9, 2011

Having a thin negative is still inportant for 35mm photography where the high degree of enlargement emphasizes grain.

Negative reading

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