Creating copies of slides: duping or internegative?

[iandvaag]

I have (colour) medium format slides that I would like to duplicate. I’m considering how I should go about this.

1. Pos-pos process (duplicating)
Without the availability of fresh duplicating film, I think this would be a challenge. I anticipate the main problem would be too high contrast (1.8 x 1.8 = 3.2 -> yikes!) I guess I would use Provia and any of the following strategies to control contrast:
-pre-flashing
-developing for less time
-tiffen ultra-contrast filters or similar (contrast reducing filters). Essentially adding in flare in a controlled way.
-pin-registered film masking

This seems like a lot of trial and error, and probably significant colour reproduction problems, even if the correct contrast is obtained.

2. Pos-neg-pos process (internegative)
a) Photograph the slide onto Portra 160. Then take the interneg and contact print onto RA-4 transparent film (“digital display material”). Hopefully the contrast would come out ok (1.8 x 0.5 x 2.5 = 2.2, still pretty high, no?).

The major downside of this method is the cost of purchasing both the interneg film and the final print film. The minimum order for the RA-4 transparent film is exorbitant. I’m not even sure if this material is suitable for making small (medium-format sized) slides for viewing in a handheld viewer.

b) Another option would be to use ECN-2 Vision-3 50D as the interneg film and some sort of ECP-2 film as the final print film. Once again, minimum orders are rather unreasonable for a schmuck like me. Also, it is unclear to me which ECP-2 film is suitable for optical printing. I am only interested in duplicating medium format slides, and it doesn’t appear that Kodak produces ECP-2 in 70mm that is designed for optical printing (only for digital exposure.)

Anyway, do any of you apuggers have any experience with duplicating slides or making slides from colour negatives? Are any of these methods likely to yield acceptable results? Are there other options? I think I probably only have time (and money!) to try one of the three options outlined above (1, 2a, 2b).

Thanks for your consideration.

Ian

 

[DREW WILEY]

Lots of experience doing both, though in my case, for big prints. If you expect high quality results, there's a steep learning curve, as well as special equip investment. Scanning for film recorder output is more realistic, but likewise expensive. Any stock of official dupe or interneg film is either outdated or downright extinct. I still sometimes make sheet film internegs for RA4 printing, but sold all my remaining frozen stash of sheet dupe film. It's involved.

 

[DREW WILEY]

For modest quality results, you'd need a macro lens for your MF camera, a copy attachment (or make one yourself), dual-exposure ability with your camera, a flashing background, appropriate light balancing filters, and a current transparency film (none of the remaining ones are ideal).

 

[darkroommike]

Some dedicated slide dupers has the option to flash during exposure, this could sure help. I remember back when we used the E-4 duplicating film, Kodak recommended shortening First Developer times for contrast reduction, that was a pain.

 

[DREW WILEY]

All kinds of slide dupers were made for 35mm, everything from toyish Spiratone fifteen buck units to pro lab gear, some of which is still avail on the used market. The general flaw was that most of these accepted mounted slides, which aren't truly flat. If you have a high-quality light box and copy stand, you can do it that way too, with any size film original.

 

[thuggins]

The general flaw was that most of these accepted mounted slides, which aren't truly flat. If you have a high-quality light box and copy stand, you can do it that way too, with any size film original.

The OM slide duplicators take both mounted and unmounted film. I've used it to try and make positives from negatives, with mixed success (you need the right kind of duplicating film). Most of the time now it is used to duplicate slides using the technology that dare not speak its name.

 

[DREW WILEY]

The "right kind of duplicating film" was gunned down at the OK Corral by the Pixel Gang because its aim wasn't too good to begin with. Today film internegs from chromes can be done well on Portra 160 if you know a few tricks. Doing the opposite - neg to chrome, well, good luck with that one, unless you've joined the outlaws yourself!

 

[iandvaag]

Thanks for the replies so far.

I guess the main question boils down to:
Do you think I'll get more acceptable results from duping onto Provia, giving a flash exposure and reducing development (still have problems in toe and shoulder), or, will the Portra 160 -> Fujitrans/Duratrans process afford a better slide (although certainly not designed for this purpose)?

Some dedicated slide dupers has the option to flash during exposure,

Yes, it looks like the Bowens Illumitran and the Beseler Dual Mode slide duplicator both have a "contrast control unit" which essentially gives a concurrent flash exposure.

mounted slides, which aren't truly flat.

As long as the slides aren't terribly wavy, will this be a noticeable effect? I know we're talking about medium format and macro distances, but slides are pretty thin, no?

 

[DREW WILEY]

They should be dead flat. And they can pop out of focus just like in a projector. Another reason I like a relatively cool light box surface.

 

[darkroommike]

Thanks for the replies so far.

I guess the main question boils down to:
Do you think I'll get more acceptable results from duping onto Provia, giving a flash exposure and reducing development (still have problems in toe and shoulder), or, will the Portra 160 -> Fujitrans/Duratrans process afford a better slide (although certainly not designed for this purpose)?


Yes, it looks like the Bowens Illumitran and the Beseler Dual Mode slide duplicator both have a "contrast control unit" which essentially gives a concurrent flash exposure.


As long as the slides aren't terribly wavy, will this be a noticeable effect? I know we're talking about medium format and macro distances, but slides are pretty thin, no?

The very last thing to try is altering First Developer times, the old E-4 duping film was made for that, newer films will probably cross-over like mad.

 

[DREW WILEY]

The best dupe film ever made was the late Astia 100F. Their official duping film was essentially tungsten-balanced old-style Astia. Provia is less accurate, but it's the best choice now. I control contrast via masking, but that's an advanced skill. So pre-flashing the film is the most realistic route. Don't try pull processing; the current Provia isn't amenable to it. Since flashing has its greatest effect in the shadows, and Provia tends to go bluish down there, you can use an 81-series warming gel in your flashing attachment to correct that.