Jay, two questions, one what steps were the 1.2 densities measured and second, what color is the 510 pyro stain? As I understand it, it is more a brownish than green stain color.
I would be more convinced if you had used PMK or ABC and your catecol developer.
Ralph, I will be glad to continue making new threads. Moderation is one thing, to close threads before they even get a chance to provide information is another one!
We're all just weary of the constant bickering. If you guys can demonstrate an ability to remain civil, moderator action won't be necessary.
Yeah, but you should at least let the thread go awry before you close it, to close it before even one response is posted is an abuse of your powers here. You might be tired of these threads, but I assure "we are all" is an exageration. Some of us are not, even if the thread does degenerate at the end.Originally Posted by Ralph Barker
Last edited by Jorge Gasteazoro; 7-Jan-2007 at 11:38.
I agree with Jorge. It does not make any sense to ban a thread unless it has gone awry, especially when you allowed the initial information to stand. Why did you not just delete that message and eliminate the thread?
And it may be a presumption on your account in determing that "we are all" weary of these threads. If you look at the last one that was not closed, you will see that it has over 1700 views, which indicates that quite a number of people were not so weary of the subject that they stayed away.
I certainly agree that people should behave with civility, and if they don't their messages should be banned, and if they continue to not act with civility they should be banned. But to close a substantive thread before there is a problem is an abuse of the forum guidelines IMO. If you are going to do that you might as well ban the subject of pyro altogether. Some might like that, but that would not be wise for a forum with so much diversity of opinion.
Sandy King
Sandy, with all due respect, which in your case is rather significant, let me say the following:
As a relative newbie, I would love to read what the masters of any technique have to say, maybe even ask a few questions once I learn enough to know what to ask.
But the main thing that made me stay away from the entire area of staining developers is, quite frankly, the spectacle of grown-up people bickering like pre-adolescents every single time the topic comes up in any form.
While there are certain participants for whom such behaviour is the norm, everybody involved in this particular area succumbs sooner or later and lets their inner child loose.
I also think that the argument about the sheer number of views doesn't say anything about civility or usefulness of the topic. Just think of it in terms of Jerry Springer Show, because that's exactly what pyro discussions are increasingly becoming.
Regards,
Marko
Ralph,
rehashing the same issues is what we do here. Are you going to start closing every thread that revisits previously posted subjects? If not, you're not moderating, you're censoring, and that is beyond the scope of your authority, in my opinion. If you don't want to participate in these threads, I won't miss you, but to deprive the members here of the access to this new, and potentially important information is absurd, and capricious.
Jorge,
510-Pyro is a pyro developer, and its stain is similar to other pyro developers. I sent you some, check it out. Which number step was measured is not important, what is important is that the steps are matched in density, and as you can see, they are. I've gone as far as I care to towards convincing you, since printing stained negatives with VC papers has little relevance for you as a platinum printer. If you're really interested, and not just being contrary, you can perform the experiment for yourself. I postedd the data so that people who hold your opinion in high regard can decide for themselves based on real data and not just hearsay and opinion, no matter how passionately held. I have no desire to get into a long diatribe, and I'm sure Ralph's finger is already on the delete button anyway. I hope this information is useful to those who print stained negatives with VC papers.
Jay
I disagree with you, it is important and the reason why different stains give different results, as I stated before if your 1.2 density was measured from different steps and not the same step when you dvevloped for the same CI, then clearly the stains have a different response, I cant understand why you are so reluctant to acknowledge this. Once I resolve the issue of spectral film response with the sensitometry I will try your developer, but although you might think the issue is not relevant to me, it actually is since the green vs brownish stain is also important for pt/pd printers. Beleive it or not, yellow/green seems to have a better UV absorption than brownish stains, thus one more fact that supports the notion that different stains are seen differently by the papers used.Which number step was measured is not important
Jay it would be best to plot a curve for each of the steps. It is entirely possible you measured a 'crossover point' in the curves.
I tend to agree though that the color of the stain really doesn't make much of a difference.
This is my last contribution to this particular discussion..
Just a few thoughts.
1. The difference between highlight compensation you get with a staining developer like PMK and a non-staining one like D76 is not a dramatic difference. Many people could use these two developers interchangeably and not notice any difference unless someone pointed it out to them. In fact, many people have compared the two for their own work and concluded that the differences are insignificant, or at least not significant enough to make them switch to a staining developer.
2. Highlight compensation itself is a fairly subtle effect. The difference in visual perception of paper white and some texture can be as little as log 0.01. And , highlight compensation that comes with PMK is at the very end of the toe of the paper curve, and therefore not easy to graph.
3. Although subtle, the stain color of a pyrogallol developer like PMK gives “much” more highlight compensation than the stain color of a pyrocatechin developer like Pyrocat-HD. There is both practical experience and spectral data that explains why.
a) First, there is considerable empirical experience from real printers who have compared results and found that there is more highlight compensation with PMK than with Pyrocat-HD. That fact by itself would not be conclusive, but there is also good spectral data that validates the experience.
b) Densitometer readings in Visual (Green Light), Blue, and UV show distinct differences in the transmission of Pyrocat-HD when compared to three different pyrogallol based developers. See <http://unblinkingeye.com/Articles/PCat/PCat3/pcat3.html>http://unblinkingeye.com/Articles/PCat/PCat3/pcat3.html What is most important for this discussion is that the difference between silver density, and silver + stain density, as measured by Visual (green light) and Blue light, is considerably greater for PMK and other pyrogallol based developers than it is for Pyrocat-HD. This clealry implies that the color of the stain of Pyrocat-HD is absorbing much less blue light than that of PMK.
c) The difference in absorption is also supported by spectrophotometer analysis. The results I have seen show that Pyrocat-HD negatives have low absorption throughout the green and all the way in the Blue to around 420 nm. A PMK negative, by contrast, has much greater absorption in the green and blue. The situation reverses in the UV, where the Pyrocat-HD stain has more absorption.
Bottom line is this. A Pyrocat-HD negative developed to exactly the same CI, as read by blue light, will not print on a VC paper exactly as a PMK negative developed to the same CI as read by blue light. The PMK negative will print with more compensation. The Pyrocat-HD negative in fact prints with much less compensation, more like a non-stained negative than a stained one. It may be possible to add filtration so that the two negatives would print the same, but not without changing the characteristics of the curve. Specifically, if you add that much filtration to a PMK negative so that it prints like a non-stained negative, you will lose highlight compensation.
IMO the method of adding magenta filtration to correct for a YFE would be primarily of interest and use to persons who use a pyrogallol based staining developer that has a lot of absorption in the blue and green, not to a pyrocatechin type one that has such a small amount of absorption in the blue and green that analysis by either Visual or Blue light gives almost the same readings. My personal opinion is that if the goal is to change the characteristics of a pyrogallol type developer so that it prints like a non-stained negative, i.e. with little or no compensation, it would be much simpler to just switch to a pyrocatechin one ( Pyrocat-HD, Pyrocat-MC, Diaxactol, etc.) that already prints that way with no adjustment, or to a traditional non-staining formula.
But that is just my opinion.
Sandy,
Besides the stain, what are the other advantages of a pyrocatechin developer (pyrocat HD) over non-staining developers (DD-X, X-tol)? I'm just trying to get a feel for staining developers, besides the stain issue. I understand this now.
A few advantages that come to mind might be the stain masking grain and more edge effects than non staining developers?
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