Ansel Adams, in The Negative, writes on the topic of the pre-exposure of film, in which the photographer makes an exposure of a uniform, non-image, illumination placed on a chosen low zone, after which the normal exposure of the subject is given on the same film or frame. What would be the effect, if any, of REVERSING the order, that is, making a normal exposure of the given subject, then later adding the non-image, low zone exposure???
It's called latensification, IIRC. Haist has a fair amount about it. I have an old magazine format photo book on increasing film speeds and it is a very thorough examination of techniques and developer by developer comparisons. So much information that used to be available no longer is.
Oh, I wandered. You can also do things like use organic vapors from, for instance, acetic acid or friendly stuff like mercury. I think what they do is bring the film up to base fog level so that any light hitting it makes a latent speck right away.
Hi, do you have the title/author for the old magazine format photo book you describe??
I'll have to get it from storage. Of course, I just put it there a week ago! :rolleyes:
I think this is it here: http://www.amazon.com/Increasing-sp...=sr_1_1?ie=UTF8&s=books&qid=1219521402&sr=8-1
I would suggest that post exposure and latensification are not at all the same.
I would suggest that post exposure and latensification are not at all the same.
I would suggest that you are even more incorrect than when you started.
What would be the effect, if any, of REVERSING the order, that is, making a normal exposure of the given subject, then later adding the non-image, low zone exposure???
So, I have a question. Why does someone who asks a simple question about pre-exposure vs post-exposure be treated to such a lot of hot air?
I am guessing that it makes no difference. I am certain that one can find out very simply. Under the same lighting conditions expose one frame, or sheet of film prior to the main exposure. Repeat the process by making the fogging exposure after the main exposure instead of before. Develop the fames identically. Print them.
Now, you know much more than the rest of us about it. The time involved was less than what was expended on all the previous posts.
Go for it.
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