Double reversal processing?

[AutumnJazz]

dr5chrome, it might help if you explained why your process is so much better than the others. You know, stuff like technical data or something. Instead of simply saying you're better than them. Anyone can say whatever they want.

 

[Ian Grant]

The secret to great imaging in reversal processing is in the first developer. To creat the best image, the first developer must be a "long scale" continous tone compensating developer. The second key to revesal processing is using a chromate-sulfuric acid bleach.

Over the next few months I'll post a number of alternative B&W Reversal processes.

The secret to mastering total control of the process is in:

1 The First Developer - choice & fine tuning the times and silver solvent content.
2 The second Developer - this can have a very significant effect on the image tones/colour, and is an area which has been neglected because most commercial processes aimed to produce neutral tones.

By mastering the processes it is possible to produce B&W Reversal slides that are equal in quality to any commercial laboratory past or present, and in some cases the results may be far better - particularly as you have greater control.

Ian

 

[Photo Engineer]

Ian;

I have to agree and disagree just slightly. I think that the second developer usually fails in producing all it can is due to the fact that 1: Most people use the same developer for both purposes and 2: Most people develop B&W to completion just like color films, and this is not always what you want except in color which is designed that way.

What do you think?

PE

 

[Ian Grant]

Ron, yes I agree, the conventional way is to reuse the first developer in most consumer kits or formulae. However that's not so in commercial processing. In some processes the second developer is by inspection, and it is also possible to give a controlled re-exposure, although that would be hard to control on a small scale.

There are alternative second developer formula which can be used as well as options for direct toning using sulphide or thiourea. It is worth exploring the methods used to control image tone/colour with reversal processing of Lantern slides, as these will often be applicable for reversal film as well.

I think it's important to explore a whole variety of options and possibilities to see what can actually be produces.

Ian

 

[isaacc7]

I think David and Ian are thinking of the word "difficult" in two different ways. Ian is right in the fact that you don't need a Ph.D in chemistry to achieve good results in reversal processing. On the other hand, there is a zero chance of getting really good results reversal processing without a fair amount of testing and possibly mixing your own chemistry from scratch. I think that David took difficult to mean the amount of time and patience it takes to nail a process across many different film types. This is what David offers with DR5, results without nearly as much time and aggravation. If you are interested in reversal processing, or if you only want to do it occasionally, you'd be nuts not to take David up on his offer that he made earlier in this thread. I can't imagine why you'd turn this offer down. I've already used his process and I love it, I'm not going to abuse his offer which was clearly made to people that haven't used it before.

 

[Photo Engineer]

After Bill Troop and I finish up the High Definition developer we are working on (presuming the work pans out), I may suggest to him that we start to look at the direct reversal process, as Ian is totally right.

PE

 

[Ian Grant]

I think David and Ian are thinking of the word "difficult" in two different ways. Ian is right in the fact that you don't need a Ph.D in chemistry to achieve good results in reversal processing. On the other hand, there is a zero chance of getting really good results reversal processing without a fair amount of testing and possibly mixing your own chemistry from scratch. I think that David took difficult to mean the amount of time and patience it takes to nail a process across many different film types. This is what David offers with DR5, results without nearly as much time and aggravation. If you are interested in reversal processing, or if you only want to do it occasionally, you'd be nuts not to take David up on his offer that he made earlier in this thread. I can't imagine why you'd turn this offer down. I've already used his process and I love it, I'm not going to abuse his offer which was clearly made to people that haven't used it before.

Isaac, I first produced B&W reversal slides as a teenager around 1969/70, I didn't have a kit, a PhD or any experience yet was able to produce very high quality B&W slides. I forget now which developer I modified. Around the same time I was processing my own Ferrania colour slides and also making Pavelle prints, both awful processes.

The degree of tweaking/fine tuning required to achieve exceptionally high quality results is well within the capabilities of anyone with a reasonable skill in Black & White processing & printing, and would only require a very small amount of testing.

None of this contradicts the difficulties of setting up and running a commercial B&W Reversal service, but using such a service can be a major disadvantage when you have to rely on a postal system to get your film to and back from the laboratory.

The huge advantages of processing your own B&W reversal films are speed and a greater control of the resulting images, but not everyone wants to do their own processing, and there are also potential downsides if you don't have mastery of the process.

When I still shot Rock bands live using E6 push processable film I always did my own push processing rather than trust a commercial lab, and it's for the same reasons I prefer to do my own B&W reversal processing.

Ian

 

[AutumnJazz]

Oh man, if you start posting about more B&W reversal processes...I would be able to hug you. I'm trying to start doing as much of my own processing at home as possible, so I want to be able to develop my own B&W slides. Right now I'm looking into the Kodak process, but more options can only lead to better slides, right?

 

[Ian Grant]

Ironically when I returned to where I'm staying yesterday there were a couple of books waiting for me which had arrived in the post. Opening the first, Developing (Jacobson) it fell open at the reversal processing page, and 3 more formulae.

Picking up Ron's (PE's) comment about re-using the first developer again, the two Kodak formulae don't. I'll post them in the articles section.

Ian

 

[Photo Engineer]

Of course they don't Ian because you are right! You should not use the same developer both times if you want to get the best results. Those formulas are right on.

If the clear starts to turn blue, the wash before it is not long enough, and if you get stains the clear is exhausted or the wash before and after the clear are not long enough. If you cannot get concentrated sulfuric acid, use 2x the amount of Formulary acid or 3x the amount of battery acid. That should approximate the amount in the formula.

PE

 

[dr5chrome]

..the correct formula for bleach in B&W reversal is; 6g p.dichromate and 12ml SA 98%, per liter.
This is outlined in the new addition of the DARKROOM COOKBOOK, our contribution the the chapter on reversal B&W.

btw, i can agree that opposition to what we do would strike conflict here, this is a DIY mostly forum. as i mentioned before, it was advised that we keep dr5 under wraps for now, but one day we will publish this recipe. I have nothing against the DIYer but i will not stand by and and accept a comment about what dr5 is unless they have correctly exposed film in hand. I would respectfully and completely disagree with both PE and IG, until they have both seen dr5 processed film. we are also not a commercial lab, we are a very high end custom lab.

dr5 is not like anything that is listed on apug. it is not any kit process, it is not the scala process.

regards
dw

 

[Photo Engineer]

..the correct formula for bleach in B&W reversal is; 6g p.dichromate and 12ml SA 98%, per liter.
This is outlined in the new addition of the DARKROOM COOKBOOK, our contribution the the chapter on reversal B&W.

I would respectfully and completely disagree with both PE and IG, until they have both seen dr5 processed film. we are also not a commercial lab, we are a very high end custom lab.

dr5 is not like anything that is listed on apug. it is not any kit process, it is not the scala process.

regards
dw

First, I would say that there are many formulas for the bleach that exist, and if you look at Ian's formula it is to be used diluted. When diluted, it approaches what you have above more closely than the concentrate. In fact, Ian's is more film friendly due to the lower level of H2SO4.

Second, based on our telephone conversations, you are aware of how much I know and how much I deduced about your process, so I feel confident in my comments being correct. Bill and I are well aware of your process and the quality that can be obtained by using it.

PE

 

[Ian Grant]

..the correct formula for bleach in B&W reversal is; 6g p.dichromate and 12ml SA 98%, per liter.
This is outlined in the new addition of the DARKROOM COOKBOOK, our contribution the the chapter on reversal B&W.

btw, i can agree that opposition to what we do would strike conflict here, this is a DIY mostly forum. as i mentioned before, it was advised that we keep dr5 under wraps for now, but one day we will publish this recipe. I have nothing against the DIYer but i will not stand by and and accept a comment about what dr5 is unless they have correctly exposed film in hand. I would respectfully and completely disagree with both PE and IG, until they have both seen dr5 processed film. we are also not a commercial lab, we are a very high end custom lab.

dr5 is not like anything that is listed on apug. it is not any kit process, it is not the scala process.

regards
dw

As Ron (PE) says there are numerous formulae for Dichromate reversal bleaches, and there's more than one published by Kodak. Kodak still recommend Permanganate bleaches as well. See their Technical data sheet H24.15. (I have seen the DW-1 Bleach Bath & DW-2 Clearing Bath formulae).

You state that you're not a commercial lab, which is quite obviously untrue. Commercial means you are making a living from the laboratory. A great many commercial labs are custom labs specialising in certain areas, Kodachrome processing, Platinum/Palladium processing, high end B&W etc etc. In your case a commercial lab with your own customised B&W reversal process. Sorry for being pedantic but non commercial would mean a DIY'er, offering a semi professional service.

The formulae used in the dr5 process aren't being discussed or questioned, in fact they are irrelevant. We are looking at how people can produce high quality B&W reversal images themselves. While you may use unique techniques, formulae etc the end result is still only a B&W reversal image.

Making available formulae to allow people to do there own B&W Reversal processing, and fine tuning or proposing better developers or methods is not an attack on your methods or processes or dr5 itself.

There are a number of members/subscribers of APUG who have considerable experience in the research and commercial production of various photographic processes which include emulsions & processing chemistry. This knowledge can be used to help other photographers, in this instance with Reversal processing.

Just to reiterate, this thread started as a discussion about the qualities of B&W Reversal processing as a whole and at no time have we made adverse comments about the dr5 process.

Ian.

 

[Jacques D.]

dr5chrome, it might help if you explained why your process is so much better than the others. You know, stuff like technical data or something. Instead of simply saying you're better than them. Anyone can say whatever they want.

Dear all,

I have no connection to dr5, except that I am one of their customers. All I can say is that they deliver superb results. It is important to remember that the ASA-ratings on the box of your film is not necessarely the ASA-rating in the dr5-process, and as always, the fresher the film, the better. Furthermore, with a few exceptions, almost every film, including high speed Delta 3200, HP5, T-Max 3200,... runs well in the process. If you have old stock such as Scala, TechPan, APX 100,... they will develop it as well with good results. Most films can be reversal processed by dr5 in classic B&W (dev 1), as well as sepia toned (dev 2). So, again with a few exceptions (Scala, Foma R-100,...), it is even impossible to compare them with anything else, simply because there is not anything else on offer.

Jacques

 

[Ian Grant]

Jaques, no-one is questioning the quality of dr5. What we are sceptical of is claims that no other process can produce comparable results, because that's untrue.

There may be no commercially available process or lab but there's no reason why there couldn't be, except the markets probably too small for another.

Ian