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05-24-2018, 04:05 PM   #16
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You're overthinking it Tuco, all i'm quoting is the technical data. I wouldn't expect a 0.25 stop to make all that much of a difference*. I develop T-max 100 at 20°C, i'm not expecting a world of difference if I develop at 22.1°C .


* Though i'm sure we can both agree that when all things are otherwise equal at the capture phase a lot of small things can lead to visible differences for good or ill in the quality of the negatives.

05-24-2018, 04:16 PM   #17
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QuoteOriginally posted by Digitalis Quote
You're overthinking it Tuco, all i'm quoting is the technical data. I wouldn't expect a 0.25 stop to make all that much of a difference*. I develop T-max 100 at 20°C, i'm not expecting a world of difference if I develop at 22.1°C .


* Though i'm sure we can both agree that when all things are otherwise equal at the capture phase a lot of small things can lead to visible differences for good or ill in the quality of the negatives.
Exactly!

It's also worth noting that the 2.25 number might be wrong in either direction. The true value might be closer to 2 or to 2.5. As silly as excessive precision might seem in many cases, rounding a value in the wrong direction only creates a greater error.
05-24-2018, 07:27 PM   #18
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QuoteOriginally posted by Digitalis Quote
..The main two drawbacks of Pyro Vs Rodinal is Pyro is toxic and the developing solution requires very pure constituents and even then it has a short shelf life.
Are you talking mixed? PMK Pyro has a 10-year shelf life as an 'A' and 'B' unmixed solution.

Perhaps I'm over thinking it. But like I said, my experience with RPX 25 so far is that it's a long toe film. Increased exposure results in little change in the tonal scale of the low values. And I already mentioned that cutting out the blue light in shadows of a long toe film with a red filter needs a little compensation for the tonal values above the toe section of the characteristic curve.

Last edited by tuco; 05-24-2018 at 07:33 PM.
05-25-2018, 02:32 AM   #19
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QuoteOriginally posted by tuco Quote
Are you talking mixed?

yes, I am. The unmixed components can last for decades if properly stored, 10 years is a conservative estimate IMO.



QuoteOriginally posted by tuco Quote
like I said, my experience with RPX 25 so far is that it's a long toe film. Increased exposure results in little change in the tonal scale of the low values.

I have no experience with RPX whatsoever so I'll leave it to your judgement - however I know Rodinal, and reduced dilution and increased agitation appears to have had unfortunate side effect of heightened activity in the highlights: causing them to blow out. Hence why I suggested a higher dilution with lower frequency agitation whilst keeping the temperature and duration of the development the same.


Last edited by Digitalis; 05-25-2018 at 04:49 PM.
05-25-2018, 07:51 AM   #20
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I do wish more people would try out this film, I really like it even though it totally burns me like this from time to time. I've shot a fair bit of it at this point; I really like it, but I've always found it to have a lot of contrast. Digitalis, I agitated 4 times (for a total of 1 seconds) once a minute. Next time I shoot with it, I'll try to be gentler with my agitations. I really think in this case it was already a bit of a high contrast scene, with somewhat high contrast film, with a red filter, and I just got the natural outcome of it all.
05-25-2018, 09:34 AM   #21
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QuoteOriginally posted by bobbotron Quote
... I agitated 4 times (for a total of 1 seconds) once a minute.
What you should do is follow a consistent agitation profile and then adjust your development time if its over/under cooked. Here is what the instruction sheet from my bottle of Rodinal said for an agitation profile.

QuoteQuote:
Agitation: Small tanks - continuously for the first minute and then tilt every 30 seconds.
They are not the best instructions. And I'd make those inversions for the first minute gentle agitations.
05-28-2018, 02:21 AM   #22
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I must say that I prefer Adox CMS II 20 ISO, in Caffenol CL-CN it's just perfect...

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