light safe question?

[stradibarrius]

At what point in the developing process does the print become light safe?
After the stop after the print enters the fix????

 

[El Gringo]

Its probably fine after its been in the stop for a short while*, but to be on the safe side I always wait until the print has been in the fix for around 10-20 secs before I turn on the room lights.

* I can attest to this with film, not paper, as I process my sheet film in BTZS tubes and the film gets exposed to light before its gets placed into the fix but after its been in the stop bath.

 

[Anon Ymous]

Why rush things? If you want to save some time, do it only with test strips. Turning on the lights after it has spent 50% of the normal time in the fixer is ok IME, but I only do it for strips, not the final print.

 

[wclark5179]

I found that turning on the lights for a peek after stop bath the print picks up some light which the fixer could wash out but why? I wait until the print is fully fixed then I fix the lights!

 

[fotch]

After the fix. Why risk the print at this stage?

 

[MattKing]

I use RC paper, and acid stop bath.

I turn on the lights after the print has been in the fix at least 30 seconds.

Matt

 

[jeroldharter]

Its probably fine after its been in the stop for a short while*, but to be on the safe side I always wait until the print has been in the fix for around 10-20 secs before I turn on the room lights.

* I can attest to this with film, not paper, as I process my sheet film in BTZS tubes and the film gets exposed to light before its gets placed into the fix but after its been in the stop bath.

Ditto. In my darkroom, I have to reach for a switch to turn the lights on. So I move the prints to the stop, agitate, move to fixer, agitate briefly, and then flip the switch.

"After the fix. Why risk the print at this stage?" fotch

There is no risk. Why wait? When I am doing test prints, I want to evaluate them as soon as I can to save time. I don't process them through the second fix for example. I flip the switch maybe 10 seconds into the fixer, take some time to evaluate the test print while it fixes, and then off to the next print. For final prints which I often do in a batch, I am busy with both hands so I don't flip the switch until the second fix simply because I am busy.

 

[Rich Ullsmith]

I do what Jerold does. With resin prints, it's a 15 second fix then into a holding bath. The second fix is at the end of the session, many prints at a time, with the lights on. Saves a helluva lotta time, and nary a problem.

 

[Rick A]

I wait until my print has reached 50% of fix time for my test, Then final print doesn't see room light until fully fixed. Just because the print has been in the stop does not mean the light sensitive halides wont expose some more. My old Kodak manuals taught me that, so I've done it that way for over four decades without any problems. I'm never in a rush in the DR, its where I go to get away from the rush of life.

Rick

 

[Kirk Keyes]

Ditto. In my darkroom, I have to reach for a switch to turn the lights on. So I move the prints to the stop, agitate, move to fixer, agitate briefly, and then flip the switch.

"After the fix. Why risk the print at this stage?" fotch

There is no risk. Why wait?

Me too.

This is another good reason to use stop bath.

 

[RalphLambrecht]

At what point in the developing process does the print become light safe?
After the stop after the print enters the fix????

I'm sure there is a point in time during the fix at which it is 'safe' to turn on the lights, and while I understand the impatience, I cannot understand the rush. I wait until the fixing time is up before turning on the lights.

No need to turn the darkroom into a race track.

 

[IloveTLRs]

If you turn the lights on while a test strip/print is in the stop bath, it will fog right before your very eyes
I usually turn the light on for test strips in the fix. Test strips I don't care about, it's the final prints that matter - which is why I'm not in a hurry.

 

[stradibarrius]

I am just wanting to learn how the process works and when each step takes effect. I'm not really in that much of a hurry.

 

[RalphLambrecht]

I am just wanting to learn how the process works and when each step takes effect. I'm not really in that much of a hurry.

Fixing
The light-sensitive ingredient of photographic paper is insoluble silver halide. During development, previously exposed silver halides are reduced to metallic silver in direct proportion to the print exposure, but the unexposed silver halides remain light sensitive and, therefore, impair the immediate usefulness of the photograph and its permanence. Consequently, all remaining silver halides must be made soluble and removed through fixing.

Fixing Process
For optimum silver-halide removal and maximum fixer capacity, prints are continuously agitated in a first fixing bath for at least 2x the ‘clearing’ time (typically 1-2 minutes), followed by an optional brief rinse and a second fixing bath for the same amount of time. The ‘clearing’ time is the least amount of fixing time required to dissolve all silver halides and is determined through a separate test.

During the fixing process, the residual silver halides are dissolved by thiosulfate without any damage to the metallic silver forming the image. The resulting soluble silver thiosulfate and its complexes increasingly contaminate the fixing bath until it no longer dissolves all silver halides.

Eventually, the solution is saturated to a point at which the capacity limit of the fixer is reached. The fresher, second bath ensures that any remaining silver halides and all insoluble silver thiosulfate complexes are rendered soluble.

Fixing Time
By the time it reaches the fixer, each 16x20-inch sheet of FB paper carries 25-35 ml of developer and stop bath. The fixing time must be long enough to overcome dilution by these now unwanted chemicals, penetrate the emulsion layer and convert all remaining silver halides.

Now, you can decide if you want to turn on the lights before the fixing time is up, or if you want to wait until the process is completed.

 

[MattKing]

Ralph:

Would your approach to this issue be different when considering RC papers?

Matt

 

[eli griggs]

I've always waited until the paper has had at least 50% time in the fix but I am always by the tray lift and drop processing so by the time I hit the lights, rapid fix has done its work and it's a non-issue.

I agree with Ralph there's no rush and I'll suggest that perhaps new printers should be taught to use non-rapid fixers for the first year or so, just so they can enjoy the pleasure of anticipation a minute or two longer as they explore the magic of the darkroom.

It's my opinion that this small space of time will often allow important introspection of the process, leading to better planing and execution of the next and future prints. Standing there rocking the tray or moving hypo around with the tongs as you examine your work is perhaps the most focused you will ever be with that image and once you start using rapid chemistry, that is lost; again, just my personal view-point.

Eli

 

[RalphLambrecht]

Ralph:

Would your approach to this issue be different when considering RC papers?

Matt

The principle is the same, but RC papers fix much quicker than FB papers. In other words, there is even less need to turn on the lights prematurely.