[Frozen in Time]

Originally Posted by thecatspajamas

A few more thoughts until later this evening: Duplicate negatives will always have some loss of detail vs. the original negative or print they were made from. The amount of loss depends on the setup and skill of the photographer producing the dupe. Probably the most common method of producing a duplicate negative is to literally photograph a print of the desired image (i.e. "take a picture of a picture"). Before the advent of scanners, photocopiers, or even the wire photo process, this would have been about the only way of "copying" a print or printed image.

The site below lists some other methods of duplicating negatives. My guess as to the next-most-common method would be what they call "contact duplication".

http://www.nedcc.org/resources/leafl...lNegatives.php

As for how to judge whether a particular negative is an original or duplicate, I find that it's usually a judgement call based on the contrast/clarity of the image (and as you say, is more easily judged by viewing a print from the negative rather than the negative itself). Some are easier to judge than others. In the same way that a poorly focused Type 1 original photo can resemble a Type 3 wire photo judging by the image itself, a poor quality original negative could look like a copy negative. The rarer case would be for a duplicate negative to look good enough to be an original, but I have seen some darn good dupes. In those cases, you might have to compare the dupe to the original to make the determination, but most times, you won't have both in hand at the same time. Otherwise, you can make some judgements by the materials (as in, a turn-of-the-century original wouldn't be on acetate safety film, and certainly not on a modern 35mm film). I think you will find a lot of the judgement calls in comparing negatives to be parallel to those you make in comparing the prints made from them.

Thanks Lance - that all makes sense. I wonder if Kodak would have a history of the film types, sizes and markings for, say the 1920's to 50's?