Kodak EDUPE Slide Duplicating Film

Have any of the contributors to the forum used the Kodak EDUPE slide duplicating film? I am curious what you might have learned about the accuracy of Kodak's recommended filter solutions and whether the indicated exposure index turned out to be accurate in your copying equipment.

My thanks to several contributors to this forum who offered suggestions through the message feature. For general information, here is what I found out in recent experimenting.

I ran a couple test rolls of edupe recently and found that Kodak's information on the film boxes was very accurate as to the filter pack required and the exposure index. The results were very good and really did not require bracketing at all, although it appeared that both plus and minus one f-stop produced good results. Plus and minus two f-stops produced slides too dark and too light.

The film is designed for "tungsten" (meaning photoflood) illumination and if you use it with strobe illumination you have to provide a pack of additional correction filters to get the proper color balance. If your light source is regular light bulbs, the color balance is different than photoflood and you have to correct for that too.

I tried it both with tungsten and strobe illumination. For tungsten I used an autobellows with slide copying attachment. This worked very well, but the film is so slow that it is below the setable exposure indexes (even with 4x compensation) for most modern cameras, so the disadvantage of this rig is that with many cameras you will have to calculate and time your exposures manually.

I also tried it in an old Honeywell Repronar and found this was ideal for working with this film, mainly because this elderly equipment was designed in the days of much slower films. The filter drawer arrangement is ideal because the filter pack recommendation changes with different production lots of the film, and it is very easy to make this adjustment. Having wratten gelatin filters on the glass slide in the filter drawer gets the filters between the light source and opal glass where they do not degrade your optical performance. Even with the thick filter pack required, the Repronar strobe produces enough light on high setting to allow copying in the range of f8 to f11, which is ideal for the repronar lens. You have enough light to work with so that you can add a color correction filter up to about .30 to the drawer without having to open up the lens too much, if you need to change the color balance of a slide. The old "manual" exposure calculator on the repronar actually goes down to the exposure index of edupe and turns out to be very accurate.

I found that I could even "dodge" hot spots out of slides by putting a strip of paper in the filter pack below the feature that I wanted to darken. You can see exactly where the paper is with the viewer light, but the strobe's light bowl diffuses the edges of the mask when you make the actual exposure.

Kodak's claim that you will have a tough time telling the dupes from the originals might be slightly optimistic, but the dupes are indeed very good.

Here is another tip on duplicating slides, for getting the color balance of your originals and duplicates to match. Put a couple of your originals on a light board with your correcponding duplicates. The light temperature of the board's light source is not too critical since we are comparing between slides, not balancing for daylight illumination. Then, insert gelatin color compensating filters behind the original until the color balance of the original and the duplicate are as near as possible. Write down the filters used.

The go to your slide duplicating unit and REMOVE filters equal in color value to what was necessary to made the original match the duplicate. For example, if you had to add a CC10Y yellow to the original to make it match the duplicate on the light board, REMOVE the equivalvent of a CC10Y from your filter pack. If your filter pack is presently a CC50Y, you would need to make it a CC40Y (10 points less).

If you do not have any of the particular filter color in the pack to remove, then you would have to add an equivalent amount of the opposing filter color as explained in the Kodak color filter books.

After comparing one or two rolls of film this way, you can "tune" your slide duplicator to almost perfect color balance.

I've never used the new E-Dupe, but I've probably run about 5000 rolls of Kodak 5071 film through a Chroma-Pro in the duplication of medical imaging slides. Your research results about the E-Dupe makes a lot of sense, and I thank you for it.

Some other hints about getting good consistant results while duplicating:

1) Processing is important. The bad thing about E-Dupe and 5071 is that they rely on E6 processing, which is no longer available everywhere and is now often done by hand or through small rotary processors. Unless you've got a trusted lab, consitancy is at the mercy of your processor. If you develop E6 yourself, your results may vary slightly depending upon the age of your chemicals. The good thing is that E6 can be "pushed" or "pulled" while manually or developing in a rotary processor by altering the duration of the first development cycle, leading to sometimes interesting results.

2) Film dyes can go bad over time. Don't leave rolls around the copystand where the heat of the lights can prematurely "age" it. Keep it in the fridge if it's going to stay around a while. You can even freeze Ektacrome films to extend their useful life somewhat beyond the printed expiration date, with good result.

3) As the bulb on your copystand or duplicator ages, your dupes will begin to pick up a slight red shift. If you have a Chroma-Pro type duplicator, this can be offset by dialing in a very slight blue/yellow wratten to compensate, increasing as the bulb ages. If you use strobes, this obviously shouldn't be an issue.

4) Don't be afraid to experiment, since sometimes you can improve poor original materials and make something more useful. You can often tweak a dark or overexposed original slide by altering the aperture as you duplicate.

5) It's fun to double-expose while duplicating to add labels, copyrights, diagrams... maybe even the moon in the clouds overhead to make that good shot into a perfect one? For labels, I used Kodak Lithographic art film for 15 years to produce customized professional-looking duplicates out of a tiny converted bathroom darkroom. "Lith" is cheap, fun, and forgiving to use and develop.

6) Fuji CDU films also give good results for duplicating, with VERY clean whites and sharp separations, but they're very slightly green/blue-shifted (Kodak films are often deliberately slightly pink-shifted to bring out facial tones [so are most RCA TV's], which might be great for wedding photographers but not quite so great for shooting Amtrak diesels). While the human eye sees this blue/green shift as "colder", it also perceives it as being "sharper" than objects that are "colorized" towards red. If you're duplicating trains and scenery, you might like Fuji films better for some applications. Fuji CDU is also developed using Kodak E6.

7) Use glass mounts on duplicates that you want to have printed, project, or archive. Kodak's paper mounts will jam in slide projectors - it's just a matter of "when", not "if", especially if it is a dark slide [dark subjects absorb more heat and twist the paper slide mount in the projection cradle] - and your slide could get ripped or bent when the projector tries to push it out. Also, glass mounts will keep the slide film protected and flat, which is good if you someday want to make prints from your slide - otherwise, the film tends to arch one way or the other, making for less consistant definition on your final print (especially if you blow it up).

That's great information, thanks very much for sharing it!

I have also done some title slides using sandwiches, including printing out the text with an inkjet printer on clear overhead projection film and photographing it with the slide, sometimes using multiple strobe flashes to get maximum depth of field.

I recently did some duplicates on the repronar with edupe for a friend who is a frequently published author, and he commented the dupes seemed much sharper than his older duplicates done by Kodak and others. This caused me to do a comparison, duplicating some originals again on edupe that I had done many years ago by Kodak. His observation was indeed correct, the repronar with edupe produces much sharper slides than the older duplicates. I think part of this is due to focusing every one individually at full open aperture before shooting the dupe. Kodak probably had their duplicator set for an average slide, I doubt they could afford to focus every one individually. But it appears that the edupe film is indeed quite good.

I recently took a batch of slides of a manufacturing operation, that were shot in an area that was a "black hole" in the factory, and brought them back up with five full f-stops overexposure (compared with an average subject). They came out really nice, with many details appearing in the background that were hard to see in the originals. So the lesson is, when it doubt, take the picture even if there isn't enough light, you may be able to bring it back nicely when duplicating.

I find there is a distinct difference between duplicating Kodachrome and Ektachrome originals. The old Kodachrome II original slides yield sharper duplicates than originals which were shot on any of the Ektachrome films. This is very noticeable under about 8x magnification viewing the slides with a loupe.