what am I doing wrong?
Some time ago I started finding these blotches in my photos. Usually randomly placed in the upper part of the frame, but some times forming a horizontal line.
Apparently this is a processing error, because I saw this happening with different film/developer combinations. I don't recall changing anything in my developing procedure recently. Agitation as recommended by Ilford, temperature +20C. Tried presoaking and got even worse results (attached). It also seems to be more apparent with shorter development times (5-8mins). Is this some sort of "uneven development"?
Thanks in advance.
The dark dots would be areas of lower density in the negative. Is it possible you're not filling the tank high enough? Some developers have more of a tendency to foam than others. A foamy layer near the top of the negative might produce a result like this. I've heard the tendency toward foaming might also increase if the tank and/or reels had wetting agent residue on them.
Maybe a fixing issue? Could be the same problem. Make sure there's enough volume.
Just throwing out some ideas here. Others might have better diagnoses.
Last edited by Michael R 1974; 10-12-2011 at 02:01 PM. Click to view previous post history.
I go with Michael's theory. If using plastic, a good soak in hot water and some white vinegar, plus scrub, is necessary once in a while, as photoflo residue does build up. With stainless steel it is not as bad but still a quick scrub to the reels after a session is a good idea.
It looks like air bubles. As most of the blotches are in the upper part of the pictures, it indicates that you may have to little developer volume. The upper reel in the developing tank must be completely covered and preferably with some margin ( at least 1 cm I would say ). When the tank rests between agitations, most of the foam that is formed will stay on the surface, but some bubbles will still be trapped under the surface.
Also don't use any wetting agent when presoaking or in the developer as this will increase the foaming. If you use wetting agent in the final rinse, be sure to wash tank and reels thoroughly afterwards in water only.
I hope this will solve your problem.
It looks like we agree. Michael and MaximusM3 wrote directly while I was checking my English spelling.
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While I can't say what it is, it doesn't look like the air bubbles I've had. Mine all were in a line right along the top where they got trapped under the reel; they weren't scattered over the frame like that. I rinse my reels in hot (50-60C) water for a minute and that's quite enough to remove any photoflo (it's only soap, not some magically tenacious adhesive); I personally wouldn't scrub with anything. And to confound you even further, I add a drop of photoflo to each 500mL batch of dev when doing small-tank/inversion development in order to prevent the bubbles getting trapped under the reel!
To see if foaming is a problem, load up your tank with scrap film and do your usual (?) minute of inversions with just plain water and a reel in there. Take the top off and see if there's foam and/or bubbles trapped between film and spiral.
In the middle of your crop, I can see a jagged tide mark which tells me that your developer is perhaps not going in very quickly or you have crazy-short dev times.
What developer is it? Any chance that something has precipitated out? Something else to consider is fungal issues with the film - I wouldn't necessarily expect that in Prague but maybe your film is particularly old?
(PS I saw the pic and thought "is that Karluv Most? I see the tourist balloon!" before I saw your location. I was there just last month!)
polyglot, sorry it's not the tourist balloon, but another case of defect (see crop attached). The balloon is on the other side of the river.
I applied a curve in PS to make it a bit more visible. And it looks really weird. All the air bubbles I got before, usually no more than 1-2 per year, had clear and sharp borders, while these are fuzzy as if the bubbles were growing. And there are many of them.
That time I developed for 5 mins in Fomadon LQN 1+10, which is not crazy-short. But then again, I experienced these "things" with 2 different films and 3 different developers...
eurgh. That still looks to me like something growing in your emulsion. Could you perhaps test by having a lab process a roll?
And 5 minutes is the absolute minimum processing time you should consider; it is definitely short even if not crazy-short. Are you agitating for all of the first 60s? Is your tank over-full or does it have a nice big air bubble at the top so that the developer will get thoroughly stirred when you invert? Do you rap the tank on your benchtop after agitation?
These sure look like air bells, but right they are fuzzy which isn't typical. I got air bells once in my life. Since that day I agitated thus:
1. Pour in developer and cap off.
2. Invert repeatedly 15 seconds about 6 inversions.
3. Rap tank on hard surface 3 times.
4. 3-4 inversions each 30 seconds followed by rap hard 3 times.
-after about 3 minutes of this I still invert on 30 seconds, but I don't rap as hard - by that time air bells are not such an issue
What is your tank? What is your agitation procedure like?