making a larger negative....

[roy]

[QUOTE=mikewhi] The Ilford literature recommended only film developers and didn't mention Dektol.Thanks.

Possibly the thing here is that the larger negatives tended to be used for alt. processes which often required a more punchy negative. I have developed sheet FP4 in paper developer on occasions to achieve this.

[glbeas]

Let me also suggest another article on the unblinkingeye.com site on making enlarged negatives by reversal processing, at http://unblinkingeye.com/Articles/NbyR/nbyr.html

Ed Buffaloe's procedure follow rather closely an ingenious method develped by Liam Lawless and published in Post Factory Photograpy some years ago. I used Liam's method for several years and can state for a fact that this method works quite well.

There is somewhat less control with the reversal process than with the positive/negative method but there are also some advantages.

From purely economic point of view this method of making enlarged negatives for alternative printing is clearly less expensive than making digital negatives

I read the atricle and thought I might be able to try it out with chemicals I had on hand in the darkroom. I had some nice Agfa ortho litho film as well as a few other brands to work with.
I didn't have any Ferro to make the bleach with but I had some C-41 bleach which I'm pretty sure is the permanganate type mentioned in the article. Only problem it doesn't seem to do a complete bleach as there is still a definite image after it seems the bleach will go no further. Then I put it into the 5% sulfite to clear it and nothing clears. So obviously the bleach is wrong for this. Is there a fundamental difference between the C-41 bleach and the permanganate/sulfuric acid bleach? Can the C-41 bleach be modified to work?
Looks like I'm going to have to make a few more shopping trips.

[Jorge]

I read the atricle and thought I might be able to try it out with chemicals I had on hand in the darkroom. I had some nice Agfa ortho litho film as well as a few other brands to work with.
I didn't have any Ferro to make the bleach with but I had some C-41 bleach which I'm pretty sure is the permanganate type mentioned in the article. Only problem it doesn't seem to do a complete bleach as there is still a definite image after it seems the bleach will go no further. Then I put it into the 5% sulfite to clear it and nothing clears. So obviously the bleach is wrong for this. Is there a fundamental difference between the C-41 bleach and the permanganate/sulfuric acid bleach? Can the C-41 bleach be modified to work?
Looks like I'm going to have to make a few more shopping trips.

As the name implies in the C41 process, you have bleach and fixer. So I am not surprised you still had some image left. The bleach is potassium dichromate not permanganate so it is a vastly different compound. Pot dichromate is dirt cheap, I use it as contrast agent in pt/pd and a little bit goes a long way. If you want to use ferry make sure you use it without the sulfite or you wont get any image back.
So to answer yor question, yes there is a big difference between the C41 blix and regular pot dichromate bleach, better just stick with the formulas given in the article.

[glbeas]

As the name implies in the C41 process, you have bleach and fixer. So I am not surprised you still had some image left. The bleach is potassium dichromate not permanganate so it is a vastly different compound. Pot dichromate is dirt cheap, I use it as contrast agent in pt/pd and a little bit goes a long way. If you want to use ferry make sure you use it without the sulfite or you wont get any image back.
So to answer yor question, yes there is a big difference between the C41 blix and regular pot dichromate bleach, better just stick with the formulas given in the article.

This wasn't the blix, it was a separate bleach and fix process. The article does mention using permanganate instead of dichromate for a less toxic version but the bleach in the C-41 kit must have a basic difference from the version in the article. Just curious as to what that difference is. It may be a while before I get my hands on the rest of the supplies needed.
I'm looking forward to trying to get a setup for doing palladium prints, I have a vacuum frame I got from work for free as well as an Olec light unit that needs work on it. I also got hold of two different Ziatype kits used and have no idea really what to do with them as they were both very different from each other in spite of claiming to be Ziatype kits. My one attempt to make a print was a flop as I had the wrong type of paper. Haven't had time to delve into it further since I got it.

[Jorge]

This wasn't the blix, it was a separate bleach and fix process. The article does mention using permanganate instead of dichromate for a less toxic version but the bleach in the C-41 kit must have a basic difference from the version in the article. Just curious as to what that difference is. It may be a while before I get my hands on the rest of the supplies needed.
I'm looking forward to trying to get a setup for doing palladium prints, I have a vacuum frame I got from work for free as well as an Olec light unit that needs work on it. I also got hold of two different Ziatype kits used and have no idea really what to do with them as they were both very different from each other in spite of claiming to be Ziatype kits. My one attempt to make a print was a flop as I had the wrong type of paper. Haven't had time to delve into it further since I got it.

Since it must be about 20 years since I developed color, I guess the kits come differently now. I remember the Beseler kit was a blix combination to save steps. It has been a long time since I read the article, so I dont remember the permanganate part, but I am sure it would work as almost any oxidizer will bleach metalic silver.

Yep, the paper has a lot to do with the quality of the image, but hang in there, once it clicks, there is no going back. WHat was the difference between the kits? perhaps we can help you, not that I am an expert on Zias, but I ruined enough negatives to tell you what not to do...

[sanking]

The article does mention using permanganate instead of dichromate for a less toxic version but the bleach in the C-41 kit must have a basic difference from the version in the article. Just curious as to what that difference is. It may be a while before I get my hands on the rest of the supplies needed.

As I recall Liam Lawless's original instructions, on which Ed Buffaloe bases his article, did not say anything about C-41. The idea that the C-41 bleach with permaganate would work just as well may be based on analgous use from another application. My advice is to forget the C-41 bleach and stay with the one that uses potassium dichromate in the formula. Liam's method worked for me the first time, and every time.


Sandy King

[glbeas]

I looked at an E-6 kit and the bleach said it had ferric EDTA whatever that is, I'd place bets on that C-41 bleach being pretty much the same thing. What is ferric EDTA? How many different compounds are out there that will serve as a photographic bleach?