Pushing Rollei RPX 100 to 400

[newfilm]

Hi guys! I'm currently got myself a roll of RPX 100 and attempt to trying out pushing it 2 stops at 400.

Massive Dev charts says for pushing 1 stop with D-76:1+1 at EI 100 is 11 minutes, EI 200 is 15 minutes, unfortuneatly it din't says anything about at EI 400, but if I were to guess, does that mean pushing 2 stops with the same dilution at EI 400 would be 18 minutes dev time?

Many thanks!

 

[btgc]

Hi guys! I'm currently got myself a roll of RPX 100 and attempt to trying out pushing it 2 stops at 400.

Massive Dev charts says for pushing 1 stop with D-76:1+1 at EI 100 is 11 minutes, EI 200 is 15 minutes, unfortuneatly it din't says anything about at EI 400, but if I were to guess, does that mean pushing 2 stops with the same dilution at EI 400 would be 18 minutes dev time?

Many thanks!

No, one stop usually is gained about adding half of initial time. You add 3 minutes for next stop which isn't enough in my opinion. I have not used D-76 so I can't calculate exactly but you get idea.

Is there specific reason to push RPX100 instead of using RPX400, btw? If it's not available to you or you want look of pushed film, I easily understand that.

 

[newfilm]

well, the original reason of the test is that I'm about to invest in bulk roll, and I'm torn between getting ISO 400 or 100 film (i'm just started so the cheaper the better), so I'm trying to find a sweet spot of which one I would get at the end, by trying to push 100 to 400 (in case I need the speed), and also about to try pulling 400 to 100 (on RPX 400/Kentmere 400), and from there trying to figure out which one to get at the end. (of course I'll primary shooting at box speed if possible, these test are just for the hack of that "just-in-case" scenario)

I'm also basically narrow down to 2 brand Kentmere and Rollei RPX (primary due to price 🙂

Developer wise I think I'm pretty much D-76 (also due to price), I might get some Rodinal too (some one on this forum suggest that it stay fresh really long!).

 

[btgc]

OK, unification is what moves QA ))
But you are close enough. I'd use 20min. as a starting point for RPX100@400 and go from there.

HC-110 and LC-29 both are good developers for good price and keep well, if these could be criteria of choice.

 

[newfilm]

I've just dev a few frame, and happy to report back that 20 minutes is great! Thanks btgc!

 

[newfilm]

I finally tried out and the following is the mix and time I used and both give really good result, and honestly I can't tell if the grain is larger or not, even pushing at ISO 800 the result is still very smooth to my eyes (of course I scan, so maybe the scanner did something I don't know) 🙂

D76: 1+1 EI 400 <-- 21 Minutes
D76: Stock EI 800 <-- 35 Minutes

the reason I used stock in pushing to 800 is because with 1+1 will takes over 45 minutes, and I don't think I want to sit in my toilet for that long flipping can.

Many Thanks!