Rodinal 1:25 and 1:50 questions

[brian steinberger]

I've been trying out HP5 at EI800 in Rodinal. I'm used to using 1:50, that's the dilution I've always used for Rodinal. My development time was 16 minutes and the negatives look pretty good. I'd like to use 1:25 to cut my development time down to 8 minutes. I'm using the combo for low contrast scenes.

Question, will grain be more apparent at 1:25 as compared to 1:50? And can I plan on the 1:25 time being half the 1:50 time?

 

[Peter Black]

Can't comment on the grain, but the MDC confirms time should be half.

http://www.digitaltruth.com/devchart.php?Film=HP5&Developer=Rodinal&mdc=Search

 

[Christopher Walrath]

I would think that, as long as you don't jink your agitation much, your grain might increase negligibly. No more. If that.

 

[fwank]

I've been trying out HP5 at EI800 in Rodinal. I'm used to using 1:50, that's the dilution I've always used for Rodinal. My development time was 16 minutes and the negatives look pretty good. I'd like to use 1:25 to cut my development time down to 8 minutes. I'm using the combo for low contrast scenes.

Question, will grain be more apparent at 1:25 as compared to 1:50? And can I plan on the 1:25 time being half the 1:50 time?

correct me if i'm wrong,

i recently switched to rodinal, so i've only developed a few rolls, but my research has told me that dilution of rodinal controls the contrast... You say you are looking for low contrast results, so is changing the dilution still going to give you the results you are looking for?

 

[applesanity]

I've never shot HP5 myself, but in my experience, going from 1+50 Rodinal for 12 minutes in Tri-X rated at EI 320, versus 1+25 Rodinal for 5 minutes, 45 seconds (again rated at EI 320), while keeping consistent temperature and agitation yields very different things. The 1+25 developed film is much grainier and accutance was stronger.

 

[Shangheye]

The relevance of low contrast scene here is that at 1:25 your contrast will go up...more so because you are also pushing the HP5+ to 800. I don't think you will get that much more grain, which tends to be more a function of agitation in this case. Increased dilution will tend to higher acutance and reduced contrast. Since you are photographing a low contrast scene anyway, 1:25 is probably OK. Rgds, Kal

 

[Thomas Bertilsson]

Less agitation with Rodinal gives a slightly finer grain. But that also lowers your highlight intensity and raises your shadow details somewhat, which in turn counter acts your goal of more contrast.

If you use this combination for low contrast scenes, worrying about tonality first, you should give less exposure and agitate often. This way you build more contrast for those low contrast scenes (where there is no true black), to bring your negative densities (spread them out, or expand) to normal levels where they print well.

It is my opinion that you have to choose between 'correct' tonality, and fine grain (or texture as I like to call it).

That HP5+ & Rodinal grain is really pretty.