When can film be safely exposed to light?

<p>During the development process, is the film light safe after it has gone through the developer and stop bath, or do you need to fix it fully first? I'm wondering because I'd like to open up the canister to see if the film is fully fixed rather than keep waiting until I know it's been sufficient time, especially as I'm at the end of the life of my fixer.</p>

<p>To be safe, when it comes out of the fixer.<br>

When working with paper I have no qualms in turning on the lights once the print is in the fixer. However, technically speaking after you've left the stop bath you've only <em>stopped the development process</em>, but not stopped the film from being sensitive to light.<br>

I run a two-fix system: my fresh fixer is labeled Fixer-A. When this becomes weak, I move it to a bottle labeled Fixer-B. My film is fixed for 8 minutes total: 4 in Fixer-A and 4 in Fixer-B. I have found it safe to visually inspect the film after the first four minute fix in Fixer-A.</p>

 

<p>From Kodak sheet, it safe after half way thru the fix process to let the film contact with light.</p>

<p>Thanks! I'm glad to know it's safe to check once I've hit the "normal" time with potentially weak fixer.</p>

<p>I fix for 12 minutes at a minimum so I never worry much about opening after or during fixing but yes 1/2 way and 1/2 way with T grain film can be 6 or more minutes remember that if that is what you use. That said remember that is also with rapid fixer.</p>

<p>You can't tell if film is fully fixed by looking.</p>

<p>Fixer is so cheap, and has such high capacity, what are you trying to save?</p>

<p>- Leigh</p>

<p> </p>

<p>"Safely?" In the camera and after it's been completely fixed. To be on the safe side, twice the clearing time based on either reliable data (from the manufacturers, not some guy on the interwebs) or your own tests.</p>

<p>My own tests with T-Max films and rapid fixer indicate a liter of typical rapid fixer is good for 10 rolls of 36 exp 35mm or 120; and with Tri-X and most other films, up to 20 rolls; all at the usual time per the manufacturer. After that the 11th roll (of T-Max film) takes much longer to fix and the 12th roll never will fix completely. Based on that I don't need to fret over a minute or two in the fixer. After the 10th roll I toss it and mix a fresh batch.</p>

<p>Anyway, what's the rush? Hurrying to take a peek seems pointless considering how time consuming the entire film process is. Relax, listen to some music or find something else to do for that extra minute or two.</p>

<p>I'm not trying to save anything or rush. I guess what I really need to do is keep track of how many rolls a given batch has fixed, then there won't be any issue.</p>

<p>I just don't want to go to my rinse step, then start unspooling my film to find that it wasn't completely fixed because the fixer was weak.</p>

<p>Jay, I just use a strip of blue masking tape on the brown jug, after mixing a fresh batch, and stroke a line for every roll( I shoot Tmax films). It's a bit easier than trying to clear a piece of film every so often although that is useful for setting initial parameters. It peels off easily for the next new batch. Another easy way to check fixer activity is with Edwal's Hypo Check:<br>

<a href="http://www.bhphotovideo.com/c/product/16686-REG/Edwal_EDHC3_4_Hypo_Check_Liquid.html">http://www.bhphotovideo.com/c/product/16686-REG/Edwal_EDHC3_4_Hypo_Check_Liquid.html</a></p>

<p><a href="http://www.bhphotovideo.com/c/product/16686-REG/Edwal_EDHC3_4_Hypo_Check_Liquid.html"></a> </p>

<p>It might help you to get some fixer test solution. I know Photographer's Formulary Mfr# 03-0180 would do the trick. Tetenhal makes (or made) something similar.</p>

<p>Henry Posner<br /><strong>B&H Photo-Video</strong></p>

<p>In theory, it should be o.k. once it has been in the stop bath.</p>

<p>The fixing time in Kodak Rapid Fixer for film is only four minutes. What's the hurry?</p>

<p>Ditto, Louis' suggestion. I use blue masking tape (great stuff) to tick mark every use of the fixer. I know from methodical testing how many uses I'll get from rapid fixer. And I use separate batches of fixer: one for T-Max films (10 rolls per liter, but test for yourself); one for all other films (up to 20 rolls per liter); one for prints.</p>

<p>The only fixer batch I don't tick mark to keep track of is the print fixer - I use hypo tester for that. Too much trouble to keep track of every square inch of paper that goes into the fixer.</p>

<p>Film is safe to look at once it is fully acidified all the way through in the stop bath. I do this from time to time with 8x10 sheet film to scare friends who think I've fogged the film when I turn the room lights on. Careful! If there is even a trace of alkaline developer still active the film will fog and you can kiss it goodbye.</p>

<p>After the stop bath, you can expose the film to light. But after its been in the fixer for a minute would be better. You can then observe the fixation process as the unexposed, dull gray color of the emulsion is dissolved away (cleared.) As a rule of thumb, film should be fixed for twice as long as it takes to clear, and it shouldn't take more than 3 minutes for film to clear (if it does, your fixer needs replacing - not replenishing, REPLACING.) <br>

However you should never used fixer that is exhausted, and should not even use fixer that is nearly exhausted, because there are chemicals in the near-exhausted fixer that can be absorbed back into the emulsion and which don't wash out easily. </p>

<p>WEll this is obvious but I am being a smartie pants...how about in the camera? :)<br>

PS after the silver has been washed away with the fixer basically.</p>

<p>*GRIN* well I have found that 1/2 way through fixing is ok if you finish fixing pretty quickly but then why?</p>

<p>I cut off the little tab at the end before loading it in the tank, and then put that in the fixer before using the fixer. With rapid fixer it should clear in less than one minute, especially with slow films.</p>

<p>One thing, though. I noticed recently that my fixed looked dark, but it is the bottle. I believe it plated out silver on the bottle! It still clears film in less than a minute, though.</p>

<p> </p>

<p>I too have heard about having the lights on at some point before fixing has taken place. I'm working on getting better at large format developing and have come across BTZS or something, Beyond The Zone System. I think the same person or company that wrote the book makes tubes for developing sheet film. They're supposed to use less chemistry and give more even development with the ability to better monitor development times if you have different lengths in a batch.</p>

<p>ANYWAYS, they have a demonstration of how to use these on YouTube. The produce has end caps that are also used to measure developer and these caps are applied in total darkness, but once developing is over, he removes the cap in normal dim room light and rolls the tubs, one end open, in a stop bath. Having one end of the tube open, they're exposed to a certain amount of room light, but that also opens the end to allow the stop bath in. He mentioned that he's never had problems with even 400 speed film. </p>