vit c developers

[rskmd]

I have been using a vitamin c/ propylene glycol/dimezone-s developer for several months. It seemed to have worked quite well with T-Max films. My last few roll of film seen to have significantly more fogging. I moved to this combination from x-tol predominantly because of the 5 liter packaging of x-tol and my desire to have a developer with long shelf life. I have never experienced x-tol failure. (I happened to have Dimezone and used that in place of phenidone as the original formula by P.Grainer called for
phenidone.)

Any ideas?

 

[gainer]

What is your activator? Is the contrast lower than usual? I'm having difficulty imagining what change in aging "A" solution could cause fogging. The failure due to oxidation of ascorbic acid should show as a reduction of everything, as the oxidation product of ascorbic acid is dehydroascorbic acid. See if adding a little bromide to the working solution has any effect.

 

[rskmd]

I'm using sodium carbonate and Borax(each5 grms/liter of working solution).
Contrast has been a bit low.I'll try the bromide(quantity?) and I think a fresh lot of film.

 

[Tom Hoskinson]

I'm using sodium carbonate and Borax(each5 grms/liter of working solution).
Contrast has been a bit low.I'll try the bromide(quantity?) and I think a fresh lot of film.

For the low contrast problem, the first thing I'd try is adding a teaspoon of sodium carbonate to your working developer - then develop a piece of unexposed film and check the fog level (either by eyeball - or with a densitometer). If the fog level looks too high, add 1 or 2 grams of potassium bromide to the working developer, then develop another piece of unexposed film and check the fog level. If the fog level is acceptable to you, then expose a piece of film to a Stouffer step wedge (or equivalent). Develop the film and evalute the contrast and Dmax.

 

[rskmd]

thank you. I tested some unexposed film, and no fogging seen. The fogged film was carried twice through airports, and I wonder if my bags were x-rayed enough to have caused fogging?

 

[Tom Hoskinson]

thank you. I tested some unexposed film, and no fogging seen. The fogged film was carried twice through airports, and I wonder if my bags were x-rayed enough to have caused fogging?

It's certainly possible that the film got a strong enough Xray dose to fog it. The Xray inspectors can (and do) crank up the Xray energy levels if they are not happy with the XRay image they are getting. Exposure to heat is another possiblity for fogging - what kind of film was it?

Best to have your high speed film hand inspected - or ship it to your destination with PHOTOGRAPHIC FILM - DO NOT XRAY labels all over the package.

 

[rskmd]

film was Tmax 400 120 and T Max 100 in readyload

 

[Maine-iac]

I'm using sodium carbonate and Borax(each5 grms/liter of working solution).
Contrast has been a bit low.I'll try the bromide(quantity?) and I think a fresh lot of film.

Way too much activator! Don't know if this is the cause of your problem, but 5g of either one should do whatever it is you want your developer to do. The borax may take a little longer than the carbonate. I also use a Phenidone/Vitamin C/propylene glycol formula, but I add a pinch (1/8 tsp) of metabisulfite to the "A" solution to lower the pH. It also (serendipity) "gets the red out" of T-grain films. Then add 5 g carbonate when I mix it. No bromide and no fog.

Larry