Developer capacity, D-23, and dilution

[John Layton]

Renaissance Wax to varnish (Strand-inspired but a passing fad for me, obviously no disrespect towards Strand!)...but be really careful with that ball of cotton that it does not leave little fragments (impossible to remove) on the print surface!

[ParkerSmithPhoto]

The "varnish" suggested isn't a varnish, but simply oil in a solvent...I'd hate to be the conservator in 100 years who has to deal with the subsequent yellowing of everything.

I, too, would be apprehensive of what might happen to the varnish. However, my experience viewing the silver gelatin Strand portfolios, which were printed in the early 70s by Richard Benson, revealed no traces of damage or discoloration from the varnish.

Benson did note that the first edition of the gravure Mexican Portfolio had a varnish coating applied by a professional house painter with a spray gun which had since completely yellowed. See Benson's talk here, starting around 42:30.

I have personally viewed the second edition of the Mexican Portfolio and there is no trace of discoloration.

[Ulophot]

Strand gave a delightful account of the first Mexican portfolio varnishing during a 5-hour interview that is on file in the Smithsonian archives in both NYC and DC. He experimented with various varnishes over the years. My impression from Walter was that the stand oil one was the one he had settled on, I don;t know when. I learned it from Walter c. 1972.

[reddesert]

That's a good point, Michael, regarding the varnish. Yes, just oil. It's a linseed oil, the same used by oil painters, if I am not mistaken, and dries. Not being a chemist, so I can't comment on its keeping properties. Walter had told me that it is removable with artist's turpentine, the same way it goes in; maybe that would give a conservator the chills as well. Although my portrait work is meant for history, I don't know that its artistic quality will merit a conservator, and as much as I revere original art work rather than copies, for the obvious reasons, in a hundred years--well, I'm confident that we'll know more about physic by then, and conservation will probably be far advanced.

FWIW, linseed oil (sometimes stand oil, which is a thicker processed variant) and turpentine is a classic oil painting medium, meaning an liquid that is mixed with oils to achieve the consistency, flow, and gloss that the painter wants. A variant is to include damar varnish, but not too much varnish or it can cause problems later.

I have no experience with using this stuff on photographic paper. On canvas, the issue to be concerned about is that the canvas must be properly primed or the paint and medium can soak into the canvas fibers. My guess is that the treatment of photo paper to coat with emulsion is similar to priming. Anyway, at least the medium is something a conservator would be familiar with.

[Kirk Gittings]

That hasn't been my experience. With regard to contrast curves and film speed, my D-23 1:1 images are basically the same as those I have made with D-76 and Pyrocat HD at comparable dilutions. To prove this to myself I did a rigorous BTZS test of HP5+ and compared the curves with those from D-76 and Pyrocat HD: they were virtually interchangeable. One test like that was convincing enough for me.

See http://www.kennethleegallery.com/html/tech/D-23.php for a few sample images.

were you doing a pre-soak in that test?

[Ken Lee]

were you doing a pre-soak in that test?

Yes. I always use a 3-5 minute pre-soak.

[Kirk Gittings]

Yes. I always use a 3-5 minute pre-soak.

Thanks. I am back to my roots doing a HABS project with 5x7 in trays. I haven’t done trays in ages. I haven’t done anything but 4x5 in BTZS tubes for a couple of decades (in D-23 for the last many years after our last discussions).

[Jim Noel]

One excellent use I don;t see mentioned in this thread, replenishment.
At the college we used to have a nitrogen burst system for 4x5. A line was painted on the tank for developer indicating proper level. When a student finished they added D-25R up to the line.
At the end of each semester, after developing wellover 1,000 negatives, i took this well used developer home. I used it to intensify negatives i knew needed help in mid-tones as well as highlights, or ones i intended to use for carbon prints. The plating of silver which happened during Normal Development times produced negatives of amazingingly beautiful scale. I retired from the college 7 years ago but I still get the same results from this old, well used developer.

[Ken Lee]

One excellent use I don;t see mentioned in this thread, replenishment.
At the college we used to have a nitrogen burst system for 4x5. A line was painted on the tank for developer indicating proper level. When a student finished they added D-25R up to the line.
At the end of each semester, after developing wellover 1,000 negatives, i took this well used developer home. I used it to intensify negatives i knew needed help in mid-tones as well as highlights, or ones i intended to use for carbon prints. The plating of silver which happened during Normal Development times produced negatives of amazingingly beautiful scale. I retired from the college 7 years ago but I still get the same results from this old, well used developer.

Amazing !

See page 12 of the remarkable Kodak Chemicals and Formulae from 1949.

Apparently, D-25 is an extra fine grain version of D-23, which Kodak considers "a soft working developer of simple formula giving normal emulsion speed"

D-25 adds some Sodium Bisulfite and Kodak says "This developer requires 50 to 100% increase in exposure".

D-25R, the replenisher for D-25 and D-23 is apparetnly D-23 with some Sodium Metaborate added. My amateur guess is that the Sodium Metaborate acts a stabilizer.

[LabRat]

Amazing !

See page 12 of the remarkable Kodak Chemicals and Formulae from 1949.

Apparently, D-25 is an extra fine grain version of D-23, which Kodak considers "a soft working developer of simple formula giving normal emulsion speed"

D-25 adds some Sodium Bisulfite and Kodak says "This developer requires 50 to 100% increase in exposure".

D-25R, the replenisher for D-25 and D-23 is apparetnly D-23 with some Sodium Metaborate added. My amateur guess is that the Sodium Metaborate acts a stabilizer.

Used D25 years ago for shooting commercial 120 processing...

D23 worked ok for 4X5 and up negs for enlarging to moderate sizes, but on roll film + enlargement , D23 was a little mushy, but the D25 variant cleaned it up a little for printing... Did some variants where 7.5gm/per liter bisulfite was added which cleaned up the grain mush, but only lost about 1/3 stop in speed... Worked well, but for smaller negs found other dev formulas that produced better edge effects esp for 35mm/120 formats... Great mid-tones!!!

The Sodium Bisulfite is an acid salt, so my guess it very slightly reduces activity... Shadow areas were "cleaner" with a little more "bite"...

Steve K