Efke 25 not clear?

athanasius80 · Jun 22, 2005

I'm shooting Efke 25 in sheet film, and although the film clears, the base seems to have a slight brownish grey tinge. Has anyone else witnessed this? My fixer tests ok, but I'll probably discard it for a new batch. Thanks.

jim appleyard · Jun 22, 2005

What dev are you using? Some devs will stain the film, even Microdol-X, although it's not thought of as a staining dev.

wildbill · Jun 22, 2005

I develop it in rodinal in a large tank without any problems yet. I've been using water stop. The maple river shot in my photo section is efke 25.

noseoil · Jun 22, 2005

Normal base for this film is a very slight pink or purple cast. Not sure about my description or color vision, but it is certainly not clear or water white. You might try a couple of drops of acid in your stop bath if you are using water, that or the fixer, but try the acid first. I use a glass rod to add three drops of 28% to 100ml of water for tube development with 4x5 for a stop bath. No pin holes from gas eruptions, but watch out for too much acid with this emulsion. tim

k_jupiter · Jun 22, 2005

athanasius80 said:
I'm shooting Efke 25 in sheet film, and although the film clears, the base seems to have a slight brownish grey tinge. Has anyone else witnessed this? My fixer tests ok, but I'll probably discard it for a new batch. Thanks.

Yep, I noticed this too. I developed it (5x7 sheet) in Pyrocat-HD and it is a brownish sort of pink. Fresh fix 6 minutes. I suspect it's a mild general stain on top of the natural base. Oh for the days of Agfa pure gray bases.

tim in san jose

jandc · Jun 22, 2005

athanasius80 said:
I'm shooting Efke 25 in sheet film, and although the film clears, the base seems to have a slight brownish grey tinge. Has anyone else witnessed this? My fixer tests ok, but I'll probably discard it for a new batch. Thanks.

The base itself is a very slight gray. The pink is unremoved anti halo dye. Presoaking and a soak in sodium sulfite after fixing generally removes all of it.

titrisol · Jun 22, 2005

jandc
sodium sulfate? or sulfite?

jandc · Jun 22, 2005

titrisol said:
jandc
sodium sulfate? or sulfite?

Thanks for catching my typo. I corected it in the above post to avoid confusion.

Donald Qualls · Jun 22, 2005

I've found that on my Fomapan 100, the sulfite post-soak works much better if the bath contains some sodium carbonate as well -- I use 2% sodium sulfite plus 1 tsp carbonate per liter, and it clears the blue dye from Fomapan sheets (where they contacted the interior of my developing tubes) in about two minutes.

titrisol · Jun 23, 2005

I believe Kodak HCA does this as well. If you prefer to buy something pre-packed of course.

jandc · Jun 23, 2005

titrisol said:
I believe Kodak HCA does this as well. If you prefer to buy something pre-packed of course.

Kodak HCA works just as well.

laser · Jun 24, 2005

Efke 25 brownish stain: dichroic fog. Also pink tint

This may be dichoric fog. Try using acetic acid stop bath. While still wet the dichoric redeposit of silver can be wiped off with cotton but this can damage the image.

The pink is residual sensitizing dye. I doubt if it is antihalation dye. Anti-halation under coats and back coats ususally aren't trying to capture red light. The dye may go into solution during development and imbibe into the antihalation layer of the film. This shows poor film design but it can happen. Changing the water in the prebath frequently can reduce this. Senstizing dye is also released when the unexposed AgX is fixed. this can aslo imbibe in other gel layers.

Washing can help but it is difficult to get it out once is gets in the swollen gel. Diffusion is slow.

Efke 25 not clear?

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