holes in emulsion

[Lou Nargi]

I been photogaphing for along time , when I started to do LF I noticed holes in the emulsion after developing them ,and with some investagation my stop seemed to be to strong . well the holes are back so I'm wondering if there is somthing I'm doing or something I sould be doing. I prewet, develope in HC110, use 1/2 ounce of stop in 32 ounces of water, fix 5minutes in kodak all purpose fixer diluted 50-50 with water.

[Jim Rice]

I would try a plain water wash instead of a stop.

[Deniz]

I used to get holes in the emulsion too.. i beleive extreme differances in the chemical temperatures can cause this. i use plain water for stop.

[Mike Davis]

Another possibility is static. I have occasionally had holes in MF negs due to static charge.

[Richard Boulware]

Most often, these type of holes happen with an chemical explosion between the alkali/acid combination between the developer and stop bath. The reaction is such that the emulsion is exploded and leaves an air bubble in the emulsion. Try a water stop, as others have said, with a thorough flush, and then try a diluted stop bath. It's kind of like when you were a kid, and poured vinegar into a cup of baking soda. Good luck. Richard.

[David Karp]

In connection with the water stop bath, you might also try an alkaline fixer. Photographer's Formulary TF4 is an example. There are also a few examples in the Darkroom Cookbook by Steve Anchell, if you prefer to mix your own.

[Kevin Crisp]

Lou: Oftentimes holes aren't really holes at all, but the clear spots from dust. I know I sent some negatives off to Kodak, complaining of holes in the emulsion and they let me know after microscopic examination that it was dust. And they were right. I am not saying these other suggestions are incorrect, but at least consider the possibility. Anybody who switches to LF from MF or 35 mm may be meeting dust issues for the first time and mistake them for something else. Not all dust shows up as squiggly lines. Good luck.

[John Cook]

The trick, as I understand it, is to use dilute acid stop. The idea is to avoid a shock between basic developer and acidic fixer. A slightly acidic stop will cushion the transition.

Several water baths may also do the trick by washing the developer off the film, neutralizing it before it hits the fixer. But this can be cumbersome. One quick water bath alone will not fully cure the problem, as it will allow the shock to take place as the film hits the fixer, instead of the stop.

Alkaline fixers may also do the trick. But I have found them to contain a milky precipitate which settles out and is a nuisance.

Use a hardening fixer, keep your chemical and wash temperatures all the same, and as low (68F) as possible. Unhardened emulsion can melt when heated. No one in the house is allowed to flush a toilet nor run the dishwasher while I am in the darkroom.

[ronald moravec]

Plain water stop and alkaline fix. If you insist in acid stop, usr plain water stop or none at all, developer straight to fix.

[Paul Metcalf]

My experience looking at negatives with reasonably high power (15x) is that chemically caused "holes" are nearly perfectly round, and holes due to dust on the film at exposure are almost never round. Get a strong mangnifier and verify that the holes are not from dust. With modern films and reasonable chemical dilutions (aka per the chemical maker's directions), I've found very few holes due to chemical causes. Oh, but the dust is another story...

[Andrew O'Neill]

Don't listen to Deniz, he's been inhaling paint fumes all day!

[Deniz]

who is Deniz?