Test for Pyro Negatives on Graded Silver Paper

[Jorge Gasteazoro]

What I have said is that developing two negatives with different staining developers to the same CI will not necessarily result in the same tones on the same grade of apepr or with the same contrast filter with VC papers. This is why I advocate the min time for max black process that Fred Picker described about 29 years ago.

And this is why you are fundamentally wrong in your testing. When you measure something you need to use the same tape measure, you cannot use one mark with cm and another in inches to compare the same thing. It works the same in photography, you can only change one variable to make comparisons.....you fail to understand this and as such your testing is flawed. Max black from min time cna be used with some modifications but not the way you use it.

[j.e.simmons]

Max black from min time cna be used with some modifications but not the way you use it.

How, then, can it be used?

juan

[steve simmons]

Even Sandy agrees that if you take two staining developers and dev negs to the same CI you will not get prints with the same range of tones. This is especially true with staining developers and vc paper becasue the color of the stain has a big influence on the contrast and what light gets through and exposes the paper. Even Sandy agrees, now anyway, that the best test is to get EPC and than make the print. Doing CI curves and matching with staining developers is just an academic exercise. Go back and read the two threads and you will have a lot more useful inofrmation.The min time for max black gives you EPC and is just how Sandy now wants to test.

steve simmons

[robert]

does anyone have a link to Bond's article? thanks

[sanking]

does anyone have a link to Bond's article? thanks

So far as I know this article is not available on the web. It is not on Howard Bond's home page, and it is not one of the articles that you can download from the PhotoTechniques archive, at least not that I can see from a look at the site.

However, I would assume that PT can provide you with a copy of the article, or a backcopy of the issue.

Sandy

[Jorge Gasteazoro]

How, then, can it be used?

juan

Very simple Juan, instead of using minimum time for maximum black, you use minimum time for Zone V tone. This way you anchor a value that will give you a family of curves within a chosen paper. If you then change contrast you still have information. The way Simmons uses it, he can only use one contrast grade and if he changes, he has to do all the tests again. Furthermore, if you change papers, all you need to do is print one step tablet to see how the contrast changed, not so with the way SImmons does it. Of course, when he is told this, he does not understand the underlying sensitometric principle for this and insist this is wrong.

Even Sandy agrees that if you take two staining developers and dev negs to the same CI you will not get prints with the same range of tones

This is wrong, it will not give the same tone distribuition but it will give you the same range of tones. Please learn to use the language of photography if you plan to continue to argue this.

[steve simmons]

We are posting detailed instructions on how to do the Minimum Time for Maximum Black Film and development Time Test in the Free Articles section of our web site. Fre Picker first described this procedure in his book The Zone VI Workshop. It was a welcome relief to Ansel's first series of books whach many people were unale to put into practical use.

I have tested many ways including this procedure and with densitometers. I always end up needing a density of about 1.35 above film base plus fog for my zone 8. I have done this on graded papers 20 years ago and on vc papers in the last few years. You can get their both ways of testing and it will work with staining and non-staining developers.

It is important to get enough exposed density on the film to get the desired shadow values and enough developed density in the high values, for me zone 8 but some people use zone 7, to get the desired high value tones. This test is aneasy and straight forward procedure.

This article should be up later today.

good luck


steve simmons

viewcamera.com

[Jorge Gasteazoro]

I have tested many ways including this procedure and with densitometers. I always end up needing a density of about 1.35 above film base plus fog for my zone 8. I have done this on graded papers 20 years ago and on vc papers in the last few years. You can get their both ways of testing and it will work with staining and non-staining developers.

Yep, and you have obtained wrong results for 20 years too....like PMK giving greater speed with film than Pyrocat HD, something anybody who has done the correct testing knows is wrong. But then, propagating wrong or incomplete information seems to be something you are good at.

[steve simmons]

"Even Sandy agrees that if you take two staining developers and dev negs to the same CI you will not get prints with the same range of tones

This is wrong, it will not give the same tone distribuition but it will give you the same range of tones. Please learn to use the language of photography if you plan to continue to argue this."



You need to go back and read his posts. He and I are in agreement. This is becasue the different staining developers will have different colors of stain and will affect what parts of the color spectrum of light reach the printing paper. VC papers are especially sensitive to the color of the stain and graded papers are less so.

I would encourage you to use a variety of resources in getting information. There are some here who are dedicated to promoting some mis-information and their behavior keeps some very knowledgeable people form participating on this forum. If you have questions about staining developers and want aanother resource beyond this forum try looking around for other forums. There are several available on the web.


steve simmons
www.viewcamera.com

[Jorge Gasteazoro]

You need to go back and read his posts. He and I are in agreement. This is becasue the different staining developers will have different colors of stain and will affect what parts of the color spectrum of light reach the printing paper. VC papers are especially sensitive to the color of the stain and graded papers are less so.

Once again, you show your lack of understanding. Tonal distribuition and tonal range given by different developers are a function of the developer and the film only and has nothing to do with the paper used to print them. On the other hand if you are talking about the reproduction cycle then you would be correct, but then this is why graded paper is used, so that the color of the stain is one more variable that is held constant when you are doing film/developer tests comparisons.

This of course is something you have failed to understand all this time we have tried to explain this to you. I would take your own advice and try to educate yourself a little bit more. Remember, I know how to use your silly little test and have identified the flaws inherent to it...you dont know how to do what I do, which is very evident in your posts here. So please, if you are going to continue to argue, try to use language that is specific enough, hell english is my second language and I can do it, why cant you?