I would like to ask some questions about an antifog. Do they have any effects to the image structures such granininess and sharpness? Why doesn't the most popular film developer D-76 has it? And what are any good and bad things that it give to the image?

Thank you, Narupol.

-- Narupol Krairiksh (note@rocketmail.com), May 25, 2002

Answers

You shouldn't need to use an antifog agent. All modern commercial developers have been formulated to give minimal fog consistent with their recommended film speed range. For instance; D-76 is inherently very clean working, and has a solvent action that an antifog agent would interfere with. Acutance developers will lose some of their sharpness if used with an anti-foggant too.
It's also not widely known that many modern films themselves already incorporate anti-fogging agents in the emulsion.

An anti-foggant might be useful for outdated film, or film that's been badly stored, or for stale printing paper, but it shouldn't be used indiscriminately, or as a matter of course. You'll just lose film speed for no reason otherwise.

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 27, 2002.

D-76 has slightly high fog compared to Agfa 17, but this isn't important, especially at D-76 and Agfa 17's pH range, both about 9, and with the combination of metol and hydroquinone. If you are doing some measurement, addition of a bit of bromide helps it produce more repeatable result. For imaging, it's not an issue.

It is probably better to distinguish organic antifoggants (such asn benzotriazole) and restrainer consisnting of alkaline metal salts of halogens. They work in different mechanisms.

Halides affects granularity through its solvent effect. However, film's silver halide also releases some amount of it so it is hard to see a clear effect unless you are doing something radical. This is more obvious with print developer, to which some people add a lot of bromide to make it warm toned, but then at some point they get dichroic fog and they have to reverse some bromide.

In film developers, you might see some loss of accutance at some level of bromide because it can make adjacency effect weaker. Some people prefer to add 1/2 to 1g of KBr to D-76H for this reason, not because of fog.

I'm playing with some restrainer combined with ascorbate fine grain developer. I'll start some new thread on this topic soon. (by the way, when do we move to photo.net?)

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 27, 2002.

Thank you all, Suzuki, Did you evey try a combination of ascorbate and p-Aminiphenol or p-Aminophenol HCl? Do you have any ideas for a result of this combibation?

Thanks very much, PS. Will you move to photo.net? Which is a channel you are?

-- Narupol (note@rocketmail.com), May 29, 2002.

Asking me about p-aminophenol developers is like calling Ilford to learn about how to process Fuji Neopan. I'm not too excited about p-aminophenol, and I don't see a big reason why I should use it over other things like metol. Plus, details like pH buffer composition and other ingredients can give a significant effect on the image, in addition to film selection -- it's hard to say in general.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 30, 2002.

Thanks, Mr. Suzuki.

So which is a superadditive deverloping agent that you mix with ascorbate (Sodium Ascorbate)? Metol? I have p-aminophenol (without HCl) and ascorbic acid and I decided to try this combination. Could you suggess me that how much is a pH for this solution?

Narupol Krairiksh.

-- Narupol Krairiksh (note@rocketmail.com), May 31, 2002.