Kodak Professional Duplicating FIlm So-339

[Cloudy]

I found a 25 sheets box of 5x4 Kodak Professional Duplicating Film So-339 expired in 1992, but I can't seem to find any info online.

Has anyone ever tried to shoot with this film instead of using it to duplicate negs?

What iso should I expose it at?

Any suggestions for developing it? I normally use Kodak HC110

Thanks

 

[Kino]

In my experience, the "SO" designation means "Special Order" and was used by Eastman Kodak when they began coating their standard emulsions onto Estar base.

Mentioned here:
http://www.taphilo.com/Photo/kodakfilmnumxref.shtml

Also mentioned here in the tech sheet for SO-132, so it was probably just a more sensitive formulation of this stock.
https://125px.com/docs/film/kodak/f11-Duplicating_SO-132.pdf

 

[voceumana]

This is a direct positive duplicating film--you can use it under the enlarger to make an enlarged (or reduced) negative, or contact print with it for a straight duplicate.

If you use it in camera, you'll get a positive image instead of a negative; it is a slow speed orthochromatic film. Develop it as you would a print.

It produces a positive image in spite of not needing reversal processing by pre-exposing the film to a dose of radiation, causing a true solarization effect (see Ansel Adams "Black Sun" image).

 

[Cloudy]

Thank you, do you have any suggestions with how many iso should I expose it at and if I can develop it in HC110?

 

[voceumana]

Data sheet (1990) says for exposure:

"You can use tungsten, fluorescent, or tungsten halogen light sources to expose this film. Make a series of test exposures under you conditions. Start with a trial exposure of 40 seconds if you use a tungsten light source that provides 5 foot candles (53 lux) at the exposure plane. More exposure produces lower densities in the duplicate; less exposure produces higher densities."

My thoughts: it has a speed similar to enlarging paper, so start with a very low ASA--try 5 as a starting point. Remember, being orthochromatic, the film is not sensitive to red light, so light sources that produce more red will not produce as much exposure as those higher in green, blue, and UV.

Developing in Dektol at 1:1 dilution is 2 minutes in tray with continuous agitation; in DK-50 (undiluted) develop for 5 minutes with agitation at 1 minute intervals. Generally, the recommended times for DK-50 undiluted are the same as for HC-110 dilution A. If you have a red safelight, you can easily develop by inspection in your dark room using trays.

The datasheet is only about 1/2 page and very skimpy on any useful info--the only exposure info is what I quoted above, and only the 2 developers are suggested.

 

[Cloudy]

Thank you, I did not know about the correlation in developing times between undiluted DK-50 and HC-110 dilution A.

Considering the the data sheet says that 5 minutes in DK-50 would result in a high contrast picture, should I dilute the HC-110 more to tame the contrast and prolong the developing time accordingly? What do you reckon?

I'll try shooting a couple of portraits in the next days at ISO 5 and I will share the results

 

[Pentode]

5 sounds about right. It'll probably be somewhere between 5 and 10.

Considering the the data sheet says that 5 minutes in DK-50 would result in a high contrast picture, should I dilute the HC-110 more to tame the contrast and prolong the developing time accordingly? What do you reckon?

Yes, the contrast will be somewhere between high and "Wow, that's high!", probably closer to the latter. Extremely dilute HC is a good idea.

 

[voceumana]

You could try dilution B for 7 minutes or so--the developing computer in the old Kodak Darkroom Dataguide gives that time and dilution as the equivalent for 5 minutes of DK-50 undiluted.

Remember, this is supposed to be a printing material, and thus development is for high contrast (as it is for regular enlargements)--Dektol, for example, is a very strong developer. Also, since you are going to end up with a positive for projection, higher contrast than in a negative is desired. Projection always reduces contrast a little--for instance, for a given negative, a contact print and a projected print to the same size, will result in a lower contrast in the projected print than the contact print. Flare is the cause--flare in the enlarger, flare in the lens, and flare in the air caused by light scatter. Contact printing eliminates all these for higher contrast.

 

[thicktheo]

This is a strange film indeed, I have a couple of boxes in the fridge and I'm quite intrigued. Still trying to rate it properly - Trying ASA 1 and HC-110(B) for 8 mins at the moment.

Did you get any usable images out of it?