400 to pushed 1600 2 stops?

I could've sworn there was a film section here, but maybe it was another forum. Hoping for a fairly quick definitive answer. I'm about to develop my first roll of B&W 120 film. It's T-Max 400 that I pushed to 1600. That's a 2 stop push, correct? 400 to 1600? I need to know for the formula for the time the developer needs to be in there.

Right here.

https://photography-on-the.net/forum/showthre​ad.php?t=727911

Will this help you any

http://www.kodak.com …lms/bw/processC​hartLo.pdf

Thanks, Macro. That's a good resource, but doesn't help me in being sure pushing a iso 400 film to iso 1600 is a 2 stop increase. Here's the Dev chart I'm looking at. You can see the formulas are quite different between the 2 stop and 3 stop. http://www.digitaltrut​h.com/devchart.php?doc​=pushproc

Although since I have all kodak chemicals, it'll help me be sure of time for the developer I have. thanks

You're welcome, I'm late to film just trying to learn as I go. I'm sure someone in the film thread can tell you the formula for sure.

Got it. This confirms that 400 pushed to 1600 is indeed a 2 stop difference.
http://www3.telus.net/​drkrm/push-pull.htm

Stamp,, I used to push process Tri-X all the time from 400 ASA to 1600 in D-76 or ID-11 ASA with great results. I also used to dilute the developer 1:1.

For rule of thumb, I use to increase development times 30%-50% for each stop pushed, depending on subject matter and lighting. Development agitation rules can be thrown out of the window when you push process. One has to be careful not to over agitate as grain and contrast will go through the roof.. What I found if I halved the agitation the results were much better. For example, if "normal" agitation was 10 seconds every minute, I'd agitate for five seconds.

I'd only used Paterson tanks and reels. Instead of giving one inversion of the tank every 60 seconds, I'd invert every two minutes. Never go shaking the tank.

When you over agitate, the grains "clump" really bad in the midtones.. Shooting medium format, grain shouldn't be too much of a problem compared to 35mm..

Push processing film is trial and error.

Yog, thanks for that! I just put it in the developer and it has about 6 minutes to go. I'm glad I didn't over agitate it, then! I got an Epson v600 scanner coming tomorrow, so I can't wait to get these scanned in and see what I got!

^^^^

Looking forward to seeing a few pics

yogestee wrote in post #12722836
^^^^

Looking forward to seeing a few pics

Ha! Me too! When I hung the film up to dry last night and looked at it this morning, it looked pretty good. Can't wait for that darn scanner to get here so I can really see them. Will post a couple when I can scan them in.

Finally got 'em scanned in. The scanner was supposed to come in Friday, but it didn't come in until yesterday, so the film negatives were kind of collecting dust and getting shuffled around on my desk for the weekend after I developed them on Thursday.

Here's the first batch. The first 5 are pushed from 400 to 1600 shot with the Mamiya, and the others were shot with the Yashica 124 all on t-max 400.

http://stampphotograph​ics.com/galleries/Film​/

Looking great Tim

yogestee wrote in post #12744539
Looking great Tim

Thanks, Jurgen. I was looking at a bunch of your photos. Lots of Nat Geo faces in there for sure. Great work!

Stamp wrote in post #12744551
Thanks, Jurgen. I was looking at a bunch of your photos. Lots of Nat Geo faces in there for sure. Great work!

Thanks mate