Chemical spots in negatives developed in PMK

[miguel_angel_p._prieto]

<p>Hi everybody,</p>

<p>I've been developing for a few months with PMK. I mainly shoot FP4 and TRI-X.<br>

I'm very happy with the results, but in the last rolls of Tri-X I've had a problem with some chemical spots.<br>

The PMK I use is mixed with distilled water as is the TF4 fixer.<br>

I developed with no presoak for 14 minutes 21ºC. Water stop bath. TF4 Alkaline fixer. 2 min After bath in used developer. water wash. I use distilled water with a couple of drops of photoflo for final rinse.</p>

<p>I've been doing this process with all my negatives with very good results. The only difference (and maybe there's the problem) is that in this case, after pouring out the developer, it passed like 20 seconds until I began to pour water in the tank for the stop bath.<br>

Maybe in that seconds some drops of developer made the spots? Is that possible?<br>

Anyway, what I heard is that the developer in that case would act in the shadows, and what I got was spots in the highlights...</p>

<p>Can anyone give some light to this problem?</p>

<p>Thank you.</p>

<div></div>

[evan_goulet]

<p>Developer acting like you describe would yield lighter spots, not darker spots. You have to think in the inverse.<br>

Perhaps these are air bells from the insufficient agitation/tapping at the start of development?</p>

[brucecahn]

<p>They look like the spots I used to get on a lot of 120 and 35mm Tri-X negatives done in D76, in the sixties. I tried everything to get rid of them. What worked was continuous agitation in the fixer. The spots stopped. </p>

[ericnelson]

<p>Evan is correct. If air bubbles sit on the film during development for any amount of time, those areas will receive less development and therefore produce thinner areas where they sat giving you darker areas in the print. Once there, there's nothing one can do. Rapping the tank frequently after each agitation esp. at the beginning of the process dislodges the bubbles so development can continue unimpeded.</p>

 

[maxim_muir]

<p>When I used PMK, I ended up doing constant agitation-period. You'll have to decrease the given starting times (I did HP5+ for 9 minutes @20C at EI 200). I didn't have a Jobo, but I used a 4/2 reel stainless steel tank, my my agitation scheme was invert, invert, twist ,bang on table, invert, invert, twist, bang and so on for the entire time. Never had a problem at all.</p>

[john romano]

<p>You may not have rinsed the film enough after the developer. I had some artifacts on my PMK negatives due to inadequate rinsing after the developer. When I went to three water rinses (as a substitute for stop bath), the problems went away.</p>

[miguel_angel_p._prieto]

<p>Thanks everyone,<br>

It makes a lot of sense that it has been an air bubbles problem at the beginning of the development. I develop in a 5 reel tank, and this time I only developed 2 reels.<br>

Maybe, agitating with much less developer than usually made more air bubbles than usually, because the liquid moves a lot in the big tank. With 5 reels, the tank is almost full, so the developer "moves" less when agitating, making much less air bubbles.</p>