Mystery fogging

[olleorama]

Had a real failed dev/print-session yesterday. I need some feedback on what went wrong. I'll start with the dev-fail. I had two rolls of 35 mm to develop, one APX100 that was quite a few years old that I found in the back of my freezer (oops!) and a freshly exposed fomapan 400. Both came from the same camera (Nikon FM2) which has never let me down. I put those two rolls on two different paterson reels, and put the reels on the spindle in the tank. The fresh fomapan in the bottom and the APX on top. On with the top and out of the changing bag. This I have done a few tens of times and never had a problem. Okay, so far so good, really not much that can have gone wrong til now.

I wanted to try out my new batch of diafine. Fresh diafine, both solutions at room temperature. 3 minutes in each solution, gentle agitation by swirling lightly a few times every 30 seconds. This was followed by two 15 seconds wash cycles. And then Tmax fixer for 3½ minutes. The fixer was not fresh, but room tempered and it should have capacity left for a few more rolls. I didn't do a clearing test. After fixing I washed and finished with photo-flo. As usual.

After drying the fomapan roll had a fogged base, and generally the looked very thin, almost bleached. The perforations didn't show any fogging, so it couldn't have been some fogging issue in the changing bag. The APX100 roll was brilliant, wonderful tonality and yet contrasty. To me this is rather strange, since it was the very same developer, wash cycles, fixer, washing and photo-flo. The 400 fomapan roll was shot at 320, measured with a handheld light meter that has produced very good exposures in the past. According some test shots I've seen, it should produce nice rich negs at EI 200. So I doubt the 'thiness' could be related to exposure. But rather the dev process.

Any ideas on what has gone wrong?

 

[jlehmus]

I haven't developed anything in Diafine, but have shot and developed quite a lot of Fomapan 400 and even without seeing your film I'd guess that underexposure is the probable cause here.

The base of normally developed and fixed Fomapan 400 in 135 size is somewhat greyish when dry. As wet it is rather clear.

 

[Rick A]

Two different films, two different developing times? Is it possible the Foma was underdeveloped, while the Agfa was slightly overdeveloped? When you say chems were at room temp, did you check with a thermometer to get actual temp, to adjust developing time? I've never processed any Foma, so I cannot comment on it, but the APX sounds alright.

Rick

 

[olleorama]

Two different films, two different developing times? Is it possible the Foma was underdeveloped, while the Agfa was slightly overdeveloped? When you say chems were at room temp, did you check with a thermometer to get actual temp, to adjust developing time? I've never processed any Foma, so I cannot comment on it, but the APX sounds alright.

Rick

The idea with diafine is that you use the same dev times for almost all different films. It's a two solution compensating developer. I have done this before, different films with different nominal ASA, with my old batch of diafine and never had a problem. But never used diafine with foma films. The temp range is seldom the problem with diafine either in my experience.

According to massive dev chart, and Dead Link Removed site 3 min A+ 3min B should be right. And the temp range for diafine is 21 to 29.5 degrees. I'm pretty sure it would have been at around 22 since it had been standing in my room for a few days, and the ambient temp is 22.

 

[olleorama]

I haven't developed anything in Diafine, but have shot and developed quite a lot of Fomapan 400 and even without seeing your film I'd guess that underexposure is the probable cause here.

The base of normally developed and fixed Fomapan 400 in 135 size is somewhat greyish when dry. As wet it is rather clear.

Hmm, but there is fogging in the space between negatives too. So would that be underexposure too? Hmm, very strange this. If it is underexposure I would have to calibrate my light meter.

 

[Ronald Moravec]

Test 6 frames or 12" of Foma in a standard developer. If there is heavy FB+Fog the product is junk or stored badly or exposed to x ray or it may just not get along with Diafine.

Personally I stay away from 1950 film emulsions from the old country. There is too much work involved try to get an image to save a few pennies on film.

Notice a the little black flecks on the bottom of the used fix? This is silver that precipitates out. It sticks like glue to the next film and does not wash off with water. I have yet to find a home method of filtering it.
So don`t use fix more than 24 hours after the first use unless you like to spot prints. Took me 3 decades to learn this so don`t be ignorant like me.

Use up the film fix on test prints. It will not go to waste.

 

[jlehmus]

Hmm, but there is fogging in the space between negatives too. So would that be underexposure too? Hmm, very strange this. If it is underexposure I would have to calibrate my light meter.

I meant that if your Fomapan 400 negs looked thin, they most probably were underexposed.

The speed of this film is significantly lower than 400 ASA, and it varies with the developer used. I'm developing mine in stock-strenght Xtol and it needs about one stop more exposure when compared to Tri-X. So the "true speed" of Fomapan 400 in Xtol is most probably somewhere around 200 ASA.

http://www.foma.cz/Upload/foma/prilohy/F_pan_400_en.pdf

Look at the Dmin curves on the data sheet, the fog level also varies with the developer. Normally the base is grayish, somewhat "matte-looking". I'm not sure, but I like to think that the "frosty" base of this film contributes to the special look of the prints.