Slide duplication film

dutchsteammachine · Apr 13, 2020

Is there any slide duplication film still being made, and if so is there a way to acquire it?

If not, is there any way to make decent slide copies of Kodachrome and ektachrome, maybe by use of filters? By using Ektachrome E100, Provia100 or any other in-production slidefilm.

Regards

koraks · Apr 13, 2020

dutchsteammachine said:
Is there any slide duplication film still being made

I don't think so. You could try ebay for some leftover dupe stocks from yesteryear.

Ian Grant · Apr 13, 2020

You could look for a Bowens slide copier, they used a flashing system to control contrast so you could use any film fr duplicates. This was important at a time when some publications would ony except 35mm slides shot on Kodachrome.

Ian

jtk · Apr 13, 2020

Ian Grant said:
You could look for a Bowens slide copier, they used a flashing system to control contrast so you could use any film fr duplicates. This was important at a time when some publications would ony except 35mm slides shot on Kodachrome.

Ian

I paid a lot of bills with Bowens Illumitran and my SLR... I used all sorts of slide films including Ektachrome dupe film, both the E4 and E6 versions. You won't like this, I suppose, but a better idea is to make digital copies...more color accuracy, no need for labs, easily backed up wherever you want, eliminates need for internegs (tho I'd use 4X5 dupe film if I still had a darkroom).

Ian Grant · Apr 13, 2020

jtk said:
I paid a lot of bills with Bowens Illumitran and my SLR... I used all sorts of slide films including Ektachrome dupe film, both the E4 and E6 versions. You won't like this, I suppose, but a better idea is to make digital copies...more color accuracy, no need for labs, easily backed up wherever you want, eliminates need for internegs (tho I'd use 4X5 dupe film if I still had a darkroom).

I don't disagree with the latter part The question was about slide duplication rather tahn digitising.

Ian

dutchsteammachine · Apr 13, 2020

I was playing with the idea to provide slide duplicates as a Patreon reward. Out of curiosity.

I mostly got B/W negatives in my collection... I assume making a positive dupe from a negative is as easy as taking a photo of it... with an other b/w neg?

iandvaag · Apr 13, 2020

I think the most satisfactory result will be to use ECN-2 film as an interneg material and print onto ECP-2. I intend to do this someday, but the minimum orders are rather expensive, and at the moment I'm a bit tied up doing emulsion making.

As for B&W (and with any duping), contrast control is the main challenge. If you start with a normal pictorial negative, it will have a contrast of maybe ~0.7. If you contact print it (or take a photo of it) onto the same negative material developed the same way, the resulting positive will have a contrast of ~0.49. The contrast curves multiply:
γtransparency = γnegative x γprint material
γtransparency = 0.7 x 0.7
γtransparency = 0.49

This will be unacceptably low contrast. The target aim for a transparency should be a contrast of about 1.7-1.8 ish. So, if you've already got a negative in hand, you'll need to print it onto a material with a contrast of about 2.5:
γtransparency = γnegative x γprint material
γprint material = γtransparency / γnegative
γprint material = 1.7 / 0.7
γprint material = 2.5

A specialty film like ortho-litho should work with the right developer. Or maybe a microfilm material? It will probably take some trial and error. Sounds like a cool project! If you do go down this route, please post your results!

railwayman3 · Apr 13, 2020

Way back in the day I made lots of B&W prints from transparencies (mainly Kodachrome) by copying onto ordinary B&W negative film, using a very simple BDB slide copier which fitted onto the ordinary camera extension tubes. I used mainly Orwo NP20 (the cheapest fresh film easily available at that time for a pennyless student), and recall that I gave slightly extra exposure and slightly less development time, to keep the contrast under control. I still have lots of 10x8 prints from this period, and the grain and sharpness is very good.

dutchsteammachine · Apr 13, 2020

iandvaag said:
I think the most satisfactory result will be to use ECN-2 film as an interneg material and print onto ECP-2. I intend to do this someday, but the minimum orders are rather expensive, and at the moment I'm a bit tied up doing emulsion making.

As for B&W (and with any duping), contrast control is the main challenge. If you start with a normal pictorial negative, it will have a contrast of maybe ~0.7. If you contact print it (or take a photo of it) onto the same negative material developed the same way, the resulting positive will have a contrast of ~0.49. The contrast curves multiply:
γtransparency = γnegative x γprint material
γtransparency = 0.7 x 0.7
γtransparency = 0.49

This will be unacceptably low contrast. The target aim for a transparency should be a contrast of about 1.7-1.8 ish. So, if you've already got a negative in hand, you'll need to print it onto a material with a contrast of about 2.5:
γtransparency = γnegative x γprint material
γprint material = γtransparency / γnegative
γprint material = 1.7 / 0.7
γprint material = 2.5

A specialty film like ortho-litho should work with the right developer. Or maybe a microfilm material? It will probably take some trial and error. Sounds like a cool project! If you do go down this route, please post your results!

So preferably a high-contrast B/W film with a low ISO, and probably a clear base, yes?

Adox Scala has a clear base and high contrast... (Scala developed as a normal negative in this case to reverse the photographed negative)

With B/W film the contrast really depends on developer and times right? so this is something we can play around with a lot.

So a high contrast film + high contrast developer + develop times also good for high contrast.

Sure if I ever try something with this i'll post the results online. It would be siccc to make slides from 35mm negatives in my collection taken in the 30's and 40's. Projecting those would really be something else.

iandvaag · Apr 13, 2020

Yeah, any of "high contrast film", "high contrast developer" and "longer developing time" can be used. As you say, high contrast, low ISO with a clear base would be good. As is the case when doing any kind of printing, the exposure given to the print/transparency is critical.

dutchsteammachine · Apr 13, 2020

Thanks for your help iandvaag,

Can I use the internal light meter of a camera? Any recommendations on type (Average, center, matix-metering), exposing for dark areas of the negative or light parts, and should any exposure compensation be applied?

I read about pre-flashing slide film in the astrophotography hobby, what did it actually do and how did it work?

jtk · Apr 13, 2020

Ian Grant said:
I don't disagree with the latter part The question was about slide duplication rather tahn digitising.

Ian

True.

The obvious question remains : Why does somebody want a duplicate slide? Certainly not for printing. Perhaps to project? For sharing? Who wants a duplicate slide?

I/we duplicated many thousand slides using cameras and lenses designed for the purpose (e.g. Sickles). People wanted duplicates, way back then, mostly for commercial purposes (slide shows).

If one sends a slide to a publisher the odds have always been high that they'll be damaged. I doubt any significant publisher wants to handle slides.

Every time a slide is projected it dies a tiny death to the projector lamp. And of course it might even be damaged by the projector itself.

It isn't just a coincidence that Kodak stopped making 4X5 duplicating film around the time they stopped making internegative film. Our lab (Media Generalists in San Francisco) also processed the original chromes for clients such as Smithsonian...all the way across the US.

IMO top quality slide duplication calls for top quality Ektachrome processing... and of course, those labs have almost entirely vanished (only two or three remain in the US?), despite the many shooters, like me, who loved slide film.

DREW WILEY · Apr 13, 2020

The correct films are no longer made. I didn't reproduce slides, but made very high quality contact and enlarged 8x10 duplicates for printing purposes on Kodak EDupe film, the Fuji CDU series of duplicating films, and finally on Astia 100F, which was the finest of them all for this purpose. The originals were unsharp masked for sake of contrast control and precise hue correction. It could get quite involved. Commercial labs generally flashed the film instead to reduce contrast - a much easier but less versatile method. Today's slide films would not do a very good job; but if you want to try, the new Kodak E100 would be the best bet. Given the fact that most pro labs with specialized equipment did a miserable job, doing it yourself won't be that easy either. It would take a lot of explanation of how to do it correctly.

DREW WILEY · Apr 13, 2020

There is quite a variety of affordable old slide duplicating gear on EBay, some basically toy quality all along, other items relatively serious. Just look up "slide duplicators".

Slide duplication film

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