Cross-Processing 7213 color neg as b&w reversal

[Marc Roessler]

Lately I had been processing 7213 as b&w negative, as described in another thread. Of course the next step was processing it with a b&w reversal process...

 

I used leftovers from my foma reversal kit (Fomadon LQR, Clearing bath, bleach bath, fixer... replenished the bleach with some fresh permanganate).

 

To my surprise it actually (somewhat) worked. Now I'd like to learn what went not-so-well and why:

 

After developing, bleaching and clearing the neg actually looked very much like a regular bleached b&w negative: lemon colored - which actually surprised me a bit, because I didn't expect the orange mask to disappear (anyone knows why?). It was a bit low-contrast, though, as expected with a color neg.

 

After re-exposing, re-developing and fixing the neg (or rather: positive) was very dark. You can see the positive image if you hold it against a strong light source, but it's much too dark. Now the fun part. The emulsion is really hammered during that long (60 minutes) reversal process, so it tends to peel off easily. This is how I found that it's actually the base that colors dark grey, thus giving a too dark positive. If it was possible to keep the base transparent, the density values of the positive image should be ok!

 

Any ideas what's happening here? Is there any way to keep the base transparent (or at least orange like it used to be?)

 

Greetings,

Marc

Edited December 14, 2010 by Marc Roessler

[Charles MacDonald]

The base of Colour negative is not orange! The orange dye is really a combination of a yellow and a magenta dye that help keep the colour true.

 

Soak a Blank piece of unprocessed film for a day and scrape the emulsion off to see the actual base colour. You will have to use something a bit alkaline to get the REM-JET off.

 

Perhaps you need a longer first development time, or the film has lost effective speed in the reversal process. Did you do an expsoure step test with under and over exposure over several stops?

[Brian Pritchard]

Did you remove the rem-jet backing? If not that is why the base looks so dark.

Brian

[Leo Anthony Vale]

Ages ago I had a roll PXR processed as reversal to see what it would look like.

 

The neg came out dark, but not under exposed. Grey scale card showed normal exposure. & there were halos around black objects.

 

So most negative stocks have more silver in their emulsions than reversal stocks do. So the first rev developer leaves a large amount of unexpossed emulsion which becomes an extremely heavy base fog after the second development.

 

This might also be going on with color neg.

[Brian Pritchard]

The amount of silver in the film won't affect the base fog when reversal processing. The high fog indicates that the first developer was insufficient. If the correct d max is not reached in the highlight areas then it leaves silver halide that can be re-developed in the second developer producing a high fog level. Insufficient bleaching will also increase the fog level.

Brian

[Leo Anthony Vale]

The amount of silver in the film won't affect the base fog when reversal processing. The high fog indicates that the first developer was insufficient. If the correct d max is not reached in the highlight areas then it leaves silver halide that can be re-developed in the second developer producing a high fog level. Insufficient bleaching will also increase the fog level.

 

Well, my test roll of 7231 rev was processed in standard Kodak reversal at HFI lab.

& it also had quite abit of drying marks.

I'd conclude that the 7231 emulsion was thicker than the reversal stocks.

[Brian Pritchard]

I believe that reversal emulsions are thicker than negative emulsions.

 

I suppose it depends whether your 7231 was put through as 'normal' reversal film or received a different development time. If your film has a high fog level then it probably didn't have sufficient development.

 

7231 is notorious for being difficult to dry so if the drying time is not sufficient you can get the film winding up wet or damp which will give you ferrotyping - shiny patches on your film. Drying marks indicate that the film was not squeegeed correctly before drying. These would be circular marks on the film.

 

Brian

[Marc Roessler]

Charles, of course you're right, it's not the base itself that is colored. Fingers faster than brain...

 

Brian, I did remove the rem jet backing, that's not the reason why it is so dark.

 

It seems that it's not actually the emulsion that is too dark (dark grey), but the base itself. As I wrote, the emulsion comes off quite easily after those 60 mins of processing. Where it came off a bit, the base was visible. It has a dark grey color. This was not easily removed by scraping! Maybe it's the coating between the base and the emulsion that's turning grey?

 

Anyone interested in pictures PM me your email address and I will send them to you.

 

Greetings,

Marc

 

P.S.: Just to clarify to avoid confusion: this was 7213 (Vision3 200T), not 7231 (Plus-X).

Edited December 17, 2010 by Marc Roessler