Thread: D-23 developer
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Old 7th December 2021, 03:41 PM
Mike O'Pray Mike O'Pray is offline
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There seems to be a range of opinions on whether D23 can deliver full box speed with say ISO 400 films and it isn't clear to me if dilution helps although if it behaves likes Perceptol then it would seem that based on Ilford speeds it almost makes 400 for HP5+ and D400 at 1+3 and does make 400 in TMax but TMax may be slightly faster than either of Ilford's 400 speed films

What appears somewhat incongruous to a layman like me is that despite the above, llford does give times for D3200 at 3200 at stock so presumably Ilford regards Perceptol as capable of good results at 3200?

What I would have expected, based on the logic of its inability to make 400 is that if we assume D3200 to be a real ISO of say 1000 then development at 800 or at a stretch 1000 might be the best it could achieve

In saying this I appreciate I am using the Perceptol information and not D23 but in terms of speed achievement in terms of development, both developers seem to be lumped together

I had a look at a few pics produced at 400 in D400 using D23 stock by Alex Luyckx and to my eye the shadow detail was very good but the pics appear to have been taken in overcast conditions where open shadows tend to be the norm

For what it is worth the MDC chart show more times at 400 for D23 than it does for Perceptol and John Finch in his Pictorial Planet video makes no mention of the need to sacrifice speed that I can recall

So I am unsure what conclusions to draw but my instinct is that,based on the range of info I have found D23 will be certainly be capable of full box speed for those films below 400 and may well be capable of getting as close to full box speed for 400 films as makes no real difference

The one thing that still leaves me puzzled based on Perceptol and D3200 is how close do both Perceptol and D23 really come to producing good negs at much above EI 1000 despite Ilford's stated times for Perceptol for EI's 1600 let alone EI 3200

Mike
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