WD2D PYRO DEVELOPER AND WATER PRE-SOAK

[PHOTOTONE]

I have been doing the water pre-soak before developing with Wd2d pyro developer and have had great success with 35mm b/w films. I recently developed a large tank of six rolls and I forgot to do the water presoak, however I did pre-fill the tank, and (in the dark) dropped the loaded reels in quickly and capped the tank and immediately started inversion agitation.
Honestly I can tell zero difference in the negatives. They scan very well. I was wondering just what is the technical REASON for the water pre-soak, and why would one want to do it with small films on reels? I understand water presoak for tray processing of sheet films, but 35mm films on reels?

 

[JBrunner]

Presoak can help prevent air bells, and promotes even development. You can get away with not doing it, but you are better off if you do.

 

[MVNelson]

I have done step tablet test with and without pre-soak and you were lucky. Really what I have seen on the film curves is that if the development times were longer than say 9 mins there was enough time for the process to "catch up". Without pre soak there is a bit of elonagation of the toe portion of the charecteristic curve(things seem to be a little slow to get started). Shortly thereafter the curve takes on its same shape as with presoak. Because of the nature of roll film photography there is some "security" over exposing going on somewhat overcoming the toe effect. Also with staining development lack of pre-soak can cause some signifigant uneveness. Lastly the pre-soak tempering helps with accuracy and repeatability IMHO. Glad though that things worked out for you without. Interestingly, when processing 4X5 film with non-staining developers in BTZS tubes many (and I) don't use pre-soak but we do allow the tubes to float in the tempering water bath prior to developing.

 

[PHOTOTONE]

Well, my developing time is 12 minutes. So, I guess the length of time in the developer compensated for the lack of a water pre-soak.

 

[Peter Schrager]

Presoak

Funny this thread came up as I've been doing some 35mm processing and I had completely forgotten about presoak. Now I'm fairly new to this format but here's what happened. FP4 developed in Xtol 1+2 ;some of the nicest looking negatives I've ever made in 35. Also doing Foma200 with 510 Pyro as semi-stand for 24 minutes-no presoak and the negatives look stunning. I've done this before with a presoak and the negatives have alot more stain without. I've proofed the FP4 negs so I'm pretty confident about those. The Foma will have to wait until next week and I'll try to post a scan...(I always use presoak with Pyrocat)
Best, Peter