ISO on old Aerial Duplicating Film?

Merissa · Feb 8, 2023

My professor was given a few canisters of this expired aerial duplicating film by some air force guys and he passed it off to me.

I guess it's supposed to be used to make copies, but I've cut it into sheets of 4x5 and loaded it to shoot in my camera. I just can't figure out what ISO it is. The info sheets I could find (here) and (here) don't say. And short of busting out the densitometer, I don't know how to find out. Anyone have experience here?

Haven't figured out how I'm going to develop it yet either, but I'll look into what the versamat chems mentioned in the kodak data sheet and see if the I can get/make something comparable.

Kino · Feb 8, 2023

Since it is a lab stock for duplication and is only blue sensitive, I assume like most dupe stocks it will be very, very low sensitivity. Try starting at ISO 6 and process it in stock D76 for 12 mintues (random guess). You could cut the sheet into 1/3 sections and process each at varying lengths of time to see how it responds. However, if you have a full roll, you have a lot to play with, so it's up to you!

Without anything real to go upon, you will just have to test...

AnselMortensen · Feb 8, 2023

Blue-sensitive, fine grain duplicating film is usually low ISO...
If it were mine, I'd try ISO 3 and bracket.
One issue is that the color of daylight changes over the course of a day, so it would be less sensitive in mornings and late afternoon warm light.
It will probably give low-contrast results...it was used to match original image contrast.
It will probably give weird skin-tone results if you try portraiture, much like wet-plate.
It's blue-sensitive, so you can develop by inspection...I'd start by processing it in paper developer, and change dilution to adjust contrast.
It's a darkroom-use film, so lot of variables....no fixed ISO.
You have a lot of it, so you can (and need to) experiment!
Hope this helps, have fun with it, and please post results!

Marcelo Paniagua · Feb 8, 2023

Kino said:
Since it is a lab stock for duplication and is only blue sensitive, I assume like most dupe stocks it will be very, very low sensitivity. Try starting at ISO 6 and process it in stock D76 for 12 mintues (random guess). You could cut the sheet into 1/3 sections and process each at varying lengths of time to see how it responds. However, if you have a full roll, you have a lot to play with, so it's up to you!

Without anything real to go upon, you will just have to test...

Good advice Kino. Usually duplicating film is very slow. Also, since this is aerial, you may get high contrast. Probably test with some low contrast developer. Just guessing here. Have used multiple aerial films and normally this kind of developer works better that regular developers like d-76.

Kino · Feb 8, 2023

Marcelo Paniagua said:
Good advice Kino. Usually duplicating film is very slow. Also, since this is aerial, you may get high contrast. Probably test with some low contrast developer. Just guessing here. Have used multiple aerial films and normally this kind of developer works better that regular developers like d-76.

Thanks, Marcelo. I print a lot of interpositive motion picture elements in B&W (2366 @ 1.40 to 1.60 gamma) and that's about how sensitive these stocks are, depending upon developer/time/temp.

Oh, one more thing Merissa; This stock should be able to be handled under safelights (dim OC should be fine) I am pretty sure, so development by inspection would be a possibility. To be sure, test a small sample before exposing anything important to the safelight.

Edit: AnselMortensen beat me to it!

Merissa · Feb 8, 2023

Kino said:
Since it is a lab stock for duplication and is only blue sensitive, I assume like most dupe stocks it will be very, very low sensitivity. Try starting at ISO 6 and process it in stock D76 for 12 mintues (random guess). You could cut the sheet into 1/3 sections and process each at varying lengths of time to see how it responds. However, if you have a full roll, you have a lot to play with, so it's up to you!

Without anything real to go upon, you will just have to test...

AnselMortensen said:
Blue-sensitive, fine grain duplicating film is usually low ISO...
If it were mine, I'd try ISO 3 and bracket.
One issue is that the color of daylight changes over the course of a day, so it would be less sensitive in mornings and late afternoon warm light.
It will probably give low-contrast results...it was used to match original image contrast.
It will probably give weird skin-tone results if you try portraiture, much like wet-plate.
It's blue-sensitive, so you can develop by inspection...I'd start by processing it in paper developer, and change dilution to adjust contrast.
It's a darkroom-use film, so lot of variables....no fixed ISO.
You have a lot of it, so you can (and need to) experiment!
Hope this helps, have fun with it, and please post results!

Marcelo Paniagua said:
Good advice Kino. Usually duplicating film is very slow. Also, since this is aerial, you may get high contrast. Probably test with some low contrast developer. Just guessing here. Have used multiple aerial films and normally this kind of developer works better that regular developers like d-76.

Thank you all for the advice! I can’t wait for Darkroom Day (Saturday) so I can get to work!

Kino · Feb 8, 2023

Merissa said:
Thank you all for the advice! I can’t wait for Darkroom Day (Saturday) so I can get to work!

Glad to help in whatever capacity! And please DO share your results regardless; we are obviously interested in the outcome.

Craig · Feb 8, 2023

Kino said:
Oh, one more thing Merissa; This stock should be able to be handled under safelights (dim OC should be fine)

The label does say to open in total darkness, so it might be more than just blue sensitive. With that product number (SO-192) it's a special order film, so it could be any emulsion.

Kino · Feb 8, 2023

Craig said:
The label does say to open in total darkness, so it might be more than just blue sensitive. With that product number (SO-192) it's a special order film, so it could be any emulsion.

That's why suggested a test prior to using a safelight! You never know...

Marcelo Paniagua · Feb 8, 2023

By the way, you probably search and read this already

Datasheet

It says there that it can indeed be handled with red sefelight. Also it hints to use KODAK Developer D-19 or KODAK Developer DK-50, although that is for expected duplicating pourpose, not for regular photography so most likely those developer wont give you results suitable for normal photography, but who knows

Regards

Marcelo

Kino · Feb 8, 2023

Depending upon your end use and your personal likes or dislikes, one could probably take just about any developer and work-out a reasonable exposure and development time/temperature to get "good" results if you are willing to put in the time and effort. Along the way, you can also discover results you never anticipated and create several new ways of shooting.

It's all good.

Don_ih · Feb 8, 2023

Since you have it in 4x5 holders, it's easy to do an exposure test. You set the camera to expose at iso 25. Pull the darkslide out 1 inch. Shoot. Pull out another inch and shoot - that's makes the first exposure ~iso12. Pull out another inch. Shoot. Etc.

Develop in a tray of Dektol. It'll be a bit harsh looking but should give you the approximate speed. If it doesn't repeat the test with the camera set to expose at iso 3.

Merissa · Feb 8, 2023

Don Heisz said:
Since you have it in 4x5 holders, it's easy to do an exposure test. You set the camera to expose at iso 25. Pull the darkslide out 1 inch. Shoot. Pull out another inch and shoot - that's makes the first exposure ~iso12. Pull out another inch. Shoot. Etc.

Develop in a tray of Dektol. It'll be a bit harsh looking but should give you the approximate speed. If it doesn't repeat the test with the camera set to expose at iso 3.

Will try this thanks!

AnselMortensen · Feb 8, 2023

3 or 4 threads down from here is another thread that might be relevant.

MarkS · Feb 9, 2023

SO-192 was designed to make positive copies from long rolls of aerial film negatives. It would be exposed in a roll-contact printer, a very large device, and developed in a Kodak Versamat processor or similar. Probably used only by the US government/military, thus its SO- designation. Maybe the commercial aerial photographers used it too.
As people have said, blue-sensitive and very slow. Not at all sure of any application for conventional photography, but worth a try. BTW, the unprocessed film is a bright yellow.

Kino · Feb 9, 2023

MarkS said:
BTW, the unprocessed film is a bright yellow.

Well... THAT alone sold me! I mean, spruce up that drab old negative file!

MarkS · Feb 12, 2023

OP, if you have any success, please share your results here. I suspect that you may end up with images that resemble wet-plate collodion.

laser · Feb 12, 2023

SO-192 in listed in Robert Shanebrook, "Making KODAK Film" page 380. This a very, very slow, gamma=1 film with a resolving power of 722 line pairs/mm on Estar Base. I think you will find it has a EI that is slower than 6. D-76 might work to give you a less than gamma of one. It was primarily used to make aerial positives from High Definition Aerial Film/3404. Seeing that it is about 30 years old testing is the best alternative. Good luck.
www.makingkodakfilm.com

Merissa · Feb 12, 2023

Back with some results. Don't get too excited, because I've had scant luck. Only 1 out of 9 exposures resulted in am image. The only explanation for this is I may have accidentally double exposed one of my images. This may have been the only one that got enough light to produce a negative. For any of you scientists out there, I shot three scenes, each at an ISO of 6, 3, and 1.5. The one I double exposed was shot at ISO 1.5, which leads me to believe the correct ISO to shoot this film at is .75.

I have a lot more testing to do. Stay tuned for more eventual updates.

(http://imgur.com/a/E4uOiKj)

Kino · Feb 12, 2023

Good start! You got an image; that's something!

BTW, it's not an accident, it's an artistic statement!

AnselMortensen · Feb 12, 2023

"Chance favors the prepared mind".

Please keep us posted with your progress.

ISO on old Aerial Duplicating Film?

Advertiser

Privacy & Transparency

Privacy & Transparency