How much extra time for D-23 with benzotriazole?

[Donald Qualls]

Looks good - hard to imagine it could look better, actually. Great job!

Given the film went out of production seventy years ago, I have no complaints. Especially since I needed nothing that wasn't already in the house to mix the developer. First time doing DBI as well -- certainly easier with ortho film under red safelight (which can be pretty bright) vs. panchro under that incredibly dim amber-green OA filter.

 

[Donald Qualls]

Okay, I used this same half-liter of developer to process two rolls of Rerapan 100 (one after the other on the same reel, same method I use for 120) -- and found out what's meant by "loss of film speed" from benzotriazole. The highlights were fine, and a couple frames that had been slightly overexposed seemed okay, but the shadows were extremely thin in the normally exposed frames.

Won't do that again; it worked out well for 70 year old film in controlling decades of age fog, but for in-date film, it cuts at least one, perhaps two stops off the true film speed.

 

[john_s]

Okay, I used this same half-liter of developer to process two rolls of Rerapan 100 (one after the other on the same reel, same method I use for 120) -- and found out what's meant by "loss of film speed" from benzotriazole. The highlights were fine, and a couple frames that had been slightly overexposed seemed okay, but the shadows were extremely thin in the normally exposed frames.

Won't do that again; it worked out well for 70 year old film in controlling decades of age fog, but for in-date film, it cuts at least one, perhaps two stops off the true film speed.

Are you reasonably sure that the activity of the developer had not declined following its previous use? I mention this because of the recent thread about D76 not being as robust as I would have expected for multiple rolls.

 

[Donald Qualls]

Are you reasonably sure that the activity of the developer had not declined following its previous use? I mention this because of the recent thread about D76 not being as robust as I would have expected for multiple rolls.

The developer was used for the single (127 size) roll of Verichrome, then stored at room temperature in a tightly closed PET bottle with very small airspace for exactly a week.

Any film developer in the D-76/D-23 range mixed as stock solution ought to still be good after this short storage time. Given factory 127 film is only about 230 square centimeters (~ 35.7 square inches => less than half a 120 roll) and normal seasoning for D-23 intended for replenishment is to process three 135-36 or 120 rolls in a liter of stock without replenishment, exhaustion shouldn't be an issue. The only factor I can see is the benzotriazole.