View Full Version : Another BTZS question

23-Feb-2011, 10:42
I just watched the BTZS tube video for 4x5 sheets again and the presenter empties the developer at the appointed time and with any caps on the tubes and the lights on he places the tubes in the stop. He makes a comment that he likes working with the light on and has never had any problems after the developer. I didn't realize film was light safe after the developer? I always thought it had to be protected until it had been in the fix for a short period.
Is is safe after the developer?

23-Feb-2011, 11:14
Light safe may be to strong a word, but the film is less sensitive to light. Do this operation quickly and prevent bright light from shining directly into the tube – and you will in all likelihood not fog the film.

23-Feb-2011, 23:20
Uhner's answer is correct. You will not fog the film but be sensible and don't try transferring the film in a darkroom with a 500watt lamp on.

I have tested with a densitomer and there is no increase in base fog if you follow the online instructions

24-Feb-2011, 06:10
Thanks for the help. I made some 4x5 BTZS tubes yesterday and I am going to give it a try. So far I have tried the "taco" method in my Patterson tank with less than satisfactory results. I have had great results with tray processing.

24-Feb-2011, 16:13
My comments are based on the genuine BTZS tubes. I cannot vouch for your tubes being light safe during development with a "white" light on in the darkroom.

Do a test with a sheet of film first before you commit to a valuable negative. I believe what the Americans call ABS [black] is considered light safe.

24-Feb-2011, 20:09
I put the tubes into the stop tray with an amber safelight on rather than room lights just so it is a dim light. Once they go in the fix tray I turn on the room lights.

As each tube finishes development, I plunge it into a tray with stop bath and periodically spin it until all of the tubes are done. This with with a safelight on and the caps off the tubes in the stop.

Once all the tubes are in the stop, I pull each sheet and place them into a slosher tray in the fixer. At that point, I turn the room lights on. I find the use of a slosher in the fixer works better to remove the pink stain from TMAX and it is fun to watch the film clear with the lights on.