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Comparison of Developers

Posted: Sat Mar 02, 2013 4:57 pm Etc/GMT-1+01:00
by Valerio Trigari
Hello guys,

I haven't posted in a while, so let's start with a question on the effect of various developers on the same type of film. I asked the same question on the FADU forum and although I got some useful answers, I've basically been told off because in the question I was mentioning a scanner. Apparently unless you're a complete analogue purist, digital stuff is frowned upon... It's actually in their rules - you probably already know about that - but I didn't take it that strictly and that was my undoing! :shock:

Anyway, back to my issue: I shot a set of 4x5 sheets of FP4+ at ISO 125, all of them with the same lighting and shooting settings, and then I developed them in the following developers:
  • Kodak D-76, 1+1, 11 min @ 20 C
  • Agfa Rodinal, 1+50, 15 min @ 20 C
  • Ilford Perceptol, 1+1, 15 min @ 20 C
I then scanned the sheets using my Epson V700, at a resolution of 4800 ppi and saved the images as TIFF. Now, when I looked at images and compared them to each other, I could not separate one from the other, even when looking at 100% magnification. I must admit I was a bit confused, because I was expecting to see at least some differences, even if not blatantly obvious ones.

Now the question: is the scanner that basically levels out any difference (as suggested on the FADU forum), or the fact that with such large negatives the differences are not significant? I do realise that printing a large size picture would probably show the effect of one developer compare to another, but I was expecting to see some hint of that when looking at the scan at large magnification. Could it also be that a flatbed scanner is not the right tool for this sort of exercise?

What are your experiences on this? Any suggestion on this is more than welcome! :)



Re: Comparison of Developers

Posted: Sat Mar 02, 2013 6:08 pm Etc/GMT-1+01:00
by Sal Santamaura
I don't know whether the scanner's capabilities are insufficient to reveal differences between those negatives, but you should certainly be able to find out by simply putting them on a light box and examining them with a moderately powerful loupe, say 15x to 30x. Your scanner's transparency illuminator can even serve as the light box is you don't have one. :) Based on having used the exact combinations myself, I'd expect substantial differences between FP4 Plus negatives developed in Rodinal 1+50 and Perceptol 1+1, especially with respect to grain.

Another potential masking issue is diffraction. If you're evaluating sharpness, the shooting aperture could have been small enough that your lens formed a blurry image which swamped any differences in resolving abilities of the film/developer combinations.

Re: Comparison of Developers

Posted: Sat Mar 02, 2013 6:44 pm Etc/GMT-1+01:00
by Valerio Trigari
Hi Sal,

thank you for your reply. Unfortunately I don't own a light box and the only loupe I have is 4x, so not that powerful. I was indeed expecting to see differences in terms of grain, but I couldn't really see them and I got perplexed...

In regards of the setting used while taking the shots, I used a 150mm lens set at f/16, which should be its optimal aperture, therefore I don't expect any loss of resolution because of diffraction.


Re: Comparison of Developers

Posted: Sat Mar 02, 2013 10:39 pm Etc/GMT-1+01:00
by Sal Santamaura
Even if your scanner's transparency illuminator is inconvenient to use, you have another "light box:" the display screen of the computer you're typing on. :) You really need to examine the negatives optically. A more powerful loupe or some other means of magnification is necessary to eliminate the scanner as a "leveling" factor.

On the other hand, of even greater importance is how you're going to print the negatives. If you plan to only make digital prints after scanning and that's the scanner you will be using, by definition the negatives are "all the same." There's no reason to worry about developers in such a situation. Use whichever is most convenient. However, your inability to see differences indicates that the particular scanner is a severe bottleneck. Maximum print size with acceptable qualities will likely be severely limited.