Kodak D-96A

[Harold33]

Table 15-6, page 19 by PDF count.
PE

I still don't see the "A" version (?)

[frobozz]

Since a previous poster referred to Plus-X and Tri-X reversal films, and they use D-94A developer, I wonder if that's where the confusion has set in. Kodak still specifies D-96 for negative camera films, but D-94A for reversal camera films. For instance:

http://motion.kodak.com/motion/uploa...ts_bw_7266.pdf

vs

http://motion.kodak.com/motion/uploa...22_techpub.pdf


(What I mean is that there is no such thing as D-96A, other than maybe some homebrewer modifying D-96 and then giving his concoction that name.)

Duncan

[Photo Engineer]

There is a D-96 modified for reversal processing. One version that I saw used KSCN as a solvent and another used DTOD. These were labeled D-96A. And now I am going crazy here trying to locate my notes on the subject.

PE

[Harold33]

As far as I understood, Kodak D-96A has nothing to do with reversal processing. According to multiple sources on the internet, it's a variant of D-96 with L-ascorbic acid 2gr. instead of hydroquinone 1.5 gr. and nothing else.

I wonder where (and when ?) it was published. I ask the question because in an article published in the Journal of Film Preservation 64, 2002, 43ff., Johan Prijs made an interesting comparaison of D-96 and D-96A using 3 gr. of L-ascorbic acid (not 2 gr.), saying that it's the official Kodak formula.

[Photo Engineer]

I am having a hard time locating any Kodak source of D96A at all and at this time am doubtful of any source as being definitive. We may never know the correct answer. All the data I can find refers to D94 very clearly with references only to D95 and not D95A. I had one old reference to D06 and can no longer find it. I'll keep looking.

PE

[Ian Grant]

Kodak never made a developer called D96A.

I've never seen an official Kodak published version of the D96A formula however they did make a "D96 Acsorbic acid" which they also called Modified D96, this replaced the Hydroquinone in D96 with L-ascorbic acid, whether there were other slight modifications is unknown.

I think Harold's right that the D96a formula published in books and on the Internet is speculative rather than based on an official Kodak publication.

Something seems to reminds me that this variant was made for some large scale cine labs who were not permitted to discharge MQ developers because of the Hydroquinone. It was sold alongside the MQ version of D96.

Ian

[nworth]

There may be more than one D-96A. PE mentioned one modified for reversal processing - in two versions, one with KSCN and another with DTOD, for permanganate bleach. I have seen two others, both ascoribic acid based. These are probably not official Kodak formulas but rather studio or lab variations that have found favor outside their original users. I have heard of a D-96 modified for sound track development also using ascorbic acid. Since that would probably need to be a high contrast developer, it is probably not the usual D-96A. Just for discussion, here are the formulas I have. They don't include the reversal processing variants.

Kodak D-96 motion picture negative developer (the official formula)
Water (50C) 750 ml
Metol 2 g
Sodium sulfite (anh) 75 g
Hydroquinone 1.5 g
Potassium bromide 400 mg
or
Sodium bromide 350 mg
Borax (decahydrate) 4.5 g
WTM 1 l
pH at 27C =8.6
Specific gravity at 27C = 1.068

Kodak D-96A film developer
Distilled water 750 ml
Calgon 1 g
Sodium bromide 350 mg
l-ascobic acid 2 g
Metol 1.5 g
Borax pentahydrate 3.8 g (or decahydrate 5 g)
Sodium sulfite 60 g
WTM 1 l
For motion picture films

Variation (D-96A2)
Calgon 1 g
Metol 1.5 g
Sodium sulfite (anh) 75 g
L-ascorbic acid 2 g
Borax (deca) 4.5 g
Potassium bromide 400 mg
Water to make 1 l
This developer works at comparable development times to D-96, but at a lower pH. Granularity and sharpness is somewhat enhanced.
Ref: silvergrain.org

[Photo Engineer]

Some general information....

Any reversal process first developer can be the same as a negative developer, but for good cleanout it must contain a strong and controllable silver halide solvent at a moderately high level in the reversal version. This is even true of the E6 process. Sulfite and Chloride do not fit this description.

Historically, KSCN (Potassium Thiocyanate) was used. So, versions of D94 and D94A came into existence. At least that is my understanding. Then KSCN got a bad rap for many reasons and DTOD began to replace it. So, at one time, EK had 2 versions for reversal processes, one with KSCN and one with DTOD. These were used at high levels (for them) as they are very powerful.

As to KSCN and any bleach, remember that there is a wash, stop or clear step in these processes after the first developer and little KSCN would be carried over into the bleach. In fact, both Dichromate and Permanganate bleaches were used for years with KSCN before DTOD was "invented" in the 60s.

PE

[Ian Grant]

I've never seen D96 as a reversal developer that's one of the others, I can't remember which off-hand D94 or D97 maybe I have them but not to hand..

What's interesting with D96 (and the ascorbic version) is how it's related to Agfa 44/Agfa Ansco 17 and the Adox Borax MQ developer with it's reduced Sulphite compared to D76, this gives better effective EI, sharpness and finer grain.

nworth, I think the sound track variants are actually lower contrast, not higher.

Ian

[Harold33]

Kodak never made a developer called D96A.
I've never seen an official Kodak published version of the D96A formula however they did make a "D96 Acsorbic acid" which they also called Modified D96, this replaced the Hydroquinone in D96 with L-ascorbic acid, whether there were other slight modifications is unknown.
Ian

I suspected something like that but I wasn't sure (a nice example of internet diffusion, by the way).
Ian, do you know a printed source for "D96 Acsorbic acid" or Modified D96 ?