Color Negative + Color Negative = Color Positive?

[Ektagraphic]

Hi Guys- I was thinking of setting up some color negs on the lightbox and then setting up a camera with some standard color negative film and shooting images of the negatives. I would think that this will give me a positive. Has anyone done this? Have you gotten good results? I do understand that for film based projection with the cine industry this is how it goes but what about with Kodak Gold 200 printed to Kodak Gold 200?

Patrick

 

[Photo Engineer]

Double masking is very ungood. The motion picture print films and color papers are unmasked for just this reason.

PE

 

[Mainecoonmaniac]

I think there's an orange mask that won't give you a color balanced positive. What you're trying to do is called in interchrome. There no easy way that I know how to make a direct positive. I'm sure there's a smart APUGer out there that can help. Good luck!

 

[hrst]

I experimented with cross-processing some E6 film in C41 for this purpose (maskless copy film). It doesn't have a mask, and it has higher contrast than C-41 camera film which is good for this "printing" purpose.

I used Fuji Sensia which gave greenish tint and greenish Dmin in C-41, but I've heard that Kodak E6 films give a nice clear Dmin in C-41. Fuji Provia 400X was quite good in my testing in this regard, also. [Edit: I can't remember exactly, but it might have been that I used ECN-2 developer for Sensia 100 test.]

If you really are into making positives from negatives, look at Kodak Vericolor Print Film. It's been discontinued around 2004, but I was able to get a 30 meter roll from Ebay and it was still in working condition and gives almost perfect Dmin. Process for this film is conveniently C-41, but as an older stock it may need a formalin stabilizer for dye stabilization.

 

[hrst]

Attachment: Fuji Superia X-tra 400 contact copied to Fuji Sensia 100, then processed either in C-41 or ECN-2 developer. I attempted this only once and made a series of three exposures, without any color balancing experiments.

So, if you find a film that cross-processes with clear Dmin and take some time in color balancing, I'm sure you can get usable results.

 

[keithwms]

Indeed the mask is a big issue.

But there is a maskless colour neg film on the market- Rollei digibase CN, that would work best for this, if you decide to try it.

 

[Photo Engineer]

Alright. Look at this another way.

The contrast of any print = contast of original negative X contrast of print film or dupe film or whatever.

Since in this case, the negative and taking film would be that of a normal color negative or about 0.6 you get 0.6 X 0.6 = 0.36 as the contrast of the print which is terrible. So, it will not work with any degree of satisfaction.

At least with E6 films you get about 0.6 X 1.7 = 1.02 which is ok but still too low. I am estimating 1.7 for the E6 cross processed, but it will likely be higher which would be good. Normal prints are 0.6 X 2.5 = 1.5 which is normal for something like Portra printed onto Endura!

PE

 

[Ektagraphic]

Thanks for the info. If I tried this with a film like Rollei's CN200 that has a clear base, should it work?

 

[hrst]

You could try to boost contrast by overdeveloping, if you are using a maskless camera color negative film like "Rollei's". Still, it will probably have too low contrast for projection, but try it, it may still look interesting.

You can see the contrast problem in my cross-processed E6 example, even if you forget the greeniness. The "whites" are not bright enough, and the blacks are not dark enough. As PE points out, the contrast will be even lower if you use a normal camera neg film.