Why can't I...

[Pawlowski6132]

...use Tmax Developer with sheet film?????

(According to Kodak.)

Joe

[memorris]

Use TMax RS developer. Some people had problems with straight TMax, the RS adds an additional chemical.

[csant]

Why can't you?

[MIke Sherck]

Supposedly because of rapid oxidation, or something like that. I used it for several years with no difficulty, only changing to D-76 because I liked D-76's contrast and expansion/contraction capabilities better.

Mike

[David de Gruyl]

I don't think it is sheet film so much as tray / open tank developing. Oxidation issues, as Mike said.

TMax RS is the equivalent replenished system, which allows it to be reused or have the bulk of the material's life extended.

[IanMazursky]

Tmax RS also eliminates Dichroic Fog problem on Tmax sheet films.
In my experience, regular Tmax developer with Tmax 100 sheet film is totally unusable.
The dichroic fog is very bad, its a silvery yellowish stain on the film.
I know it can be removed with farmers reducer buts its a pain and it doesn't always work.
The dichroic fog doesn't happen on most other sheet films with regular Tmax developer.

[seabird]

Tmax RS also eliminates Dichroic Fog problem on Tmax sheet films.
In my experience, regular Tmax developer with Tmax 100 sheet film is totally unusable.
The dichroic fog is very bad, its a silvery yellowish stain on the film.
I know it can be removed with farmers reducer buts its a pain and it doesn't always work.
The dichroic fog doesn't happen on most other sheet films with regular Tmax developer.

Ian, thanks for the explanation.

Just what is "dichroic fog"? And why are T-Max films in T-Max dev susceptible but not when souped in T-Max RS?

Are there situations when dichroic fog is a good thing? And if so, is the degree of fogging controllable?

Cheers

[David Woods]

purple-green bloom usually seen on negatives and caused by the formation of silver in the presence of an acid.
DICHROIC FOG-A deposit of colloidal silver on a photographic film caused by improper processing. This deposit commonly appears red by transmitted light and greenish by reflected light.
If film laden with developer is put straight into the fixer without going through the stop bath then an iridescent sheen, dichroic fog, forms on the surface of the film. Similar results can occur with contaminated or exhausted chemical baths, particularly weak or non-acidic stop baths.

This sheen looks like one colour when viewed under reflective light but another if viewed through transmissive light, hence the name “dichroic.”

[jnantz]

hi joe

some people have had no trouble at all
with sheet film and tmax developer.

i guess it all depends on how lucky you feel ;)

i had trouble with "the fog" and won't use that stuff again,
regular or RS ...

good luck!

john

[IanMazursky]

Hi Carey,

Dichroic fog is not desirable at all and not very controllable from what i can see.
To me i think of it more as a surface stain then a fogging, since it can be removed not only by a reducer but by rubbing it with your fingers.
I don't know why tmax film is susceptible to it, but kodak created the RS developer to partly deal with the DF situation.
Im not sure if its any better with tray processing but rotary tube is horrible with regular tmax dev.
Once i switched to RS the film came out perfect.

[seabird]

David & Ian,

Thanks for the further explanations.

Cheers

[jnantz]

if you get DF you can remove it using farmers reducer ..
that is what i did to remove it when it was on my film.
rs they say has other reasons for being made as well
it's been suggested that it is abbreviation for
replenishment system, and rotary system because
because it was made for large labs ...

when i first used it, the developer was suggested to me
to use with tmax100 film, by the folks at kodak. they didn't say rs, they just
said tmax developer. the first few sheets ( tests ) i put through seemed really nice,
and then the film i shot for a client got the fog on it ... when i called kodak
they said to throw the film out because it was trashed ... paul krot at sprint systems
was a phone call away, so i called him and he helped me remove it, nice guy he was :)

of course when i called kodak to tell a supervisor at professional services what had happened,
the person who helped me originally was disappeared and no one had any idea who it was that i spoke with.
it was kind of funny now that i think about it ...