GraemeMitchell
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but IMHO the most significant point about Pyro is it is a tannin developer. the hardening effect stops migration of the exposed silver which keeps our highlight detail very detailed.
Bob, could you elaborate on what this means when using non-staining devs?
I mean, say w/ d-76 or HC-110, are you saying while developing that the silver and image structure migrates in the highlights...? Do you think this have any correlation to the old practice of keeping the wet time of the film to a minimum (something that's been argued as false here, but which I was always taught..."don't let the grain swim around!")?
I ask, b/c there's a fellow I know and respect who runs very very very good film. He and I use the same dev, and when on rare occasion I've had him run my film, the one major difference I've noticed is how much sharper, acute in grain, and more tonal separation, he achieves in the highlights and say zone 7 and up.
I've often wondered what the difference is in how we handle the film...and I thought he may just develop to a higher CI more aggressively, but your above statement about silver migrating in the highlights made me wonder if there could be other things at play.
Apologies for derailing the thread!
I'm obviously not Bob Carnie (which is good for him), but I'd like to ask if your acquaintance maybe runs a replenished version of the same developer you use? That would give sharper negatives that are more acute, and with slightly finer grain.
Just an aside to your thought process.
- Thomas
Bob, could you elaborate on what this means when using non-staining devs?
I mean, say w/ d-76 or HC-110, are you saying while developing that the silver and image structure migrates in the highlights...? Do you think this have any correlation to the old practice of keeping the wet time of the film to a minimum (something that's been argued as false here, but which I was always taught..."don't let the grain swim around!")?
I ask, b/c there's a fellow I know and respect who runs very very very good film. He and I use the same dev, and when on rare occasion I've had him run my film, the one major difference I've noticed is how much sharper, acute in grain, and more tonal separation, he achieves in the highlights and say zone 7 and up.
I've often wondered what the difference is in how we handle the film...and I thought he may just develop to a higher CI more aggressively, but your above statement about silver migrating in the highlights made me wonder if there could be other things at play.
Apologies for derailing the thread!
I'm obviously not Bob Carnie (which is good for him), but I'd like to ask if your acquaintance maybe runs a replenished version of the same developer you use? That would give sharper negatives that are more acute, and with slightly finer grain.
Just an aside to your thought process.
- Thomas
Bob, thanks for that info. Much much appreciated. I was just wondering, an ongoing curiosity of always tweaking stuff on my end.
You're saying, "Agitation can have a tremendous effect in the highlight region which would cause softening in the highlights, otherwise I do not have an answer" - along maybe w/ just using slightly different dilutions, is where I'm seeing the difference.
Might shoot yo a PM quick as not to take this further off track.
You are over 6ft, much younger , good looking and obviously pretty smart guy,.
I am short, old , ugly and as Dinesh will agree really dumb.
I want to be you.
Ha. Careful what you wish for. I have demons.
As an aside, though, I can completely relate to the 'naked bulb' in a room and pyro developers. I used Sandy King's Pyrocat-MC formula for a couple of years, and that highlight control was one thing that I noticed as an extreme strength of that developer.
The reason I stopped using it was that I had some problems with cross contamination and screwed up more than enough important negatives because of it. But I also don't shoot in very high brightness range situations, where the pyro developers will truly shine, so I went for something different.
- Thomas
But my experience with Pyrocat-MC, which uses a different developing agent, I think, was definitely in highlight control. You can prevent highlights from blocking up with replenished Xtol if you want. You just have to be careful to not develop too long. But with Pyrocat, you get more separation in the highlights, better contrast, in a negative of the same overall contrast. That's the key. Both developers can develop negatives of identical contrast index. But within the tone scale from the bottom of the shadow details to the top of the highlights, pyro has better local contrast in the highlight spectrum. You may like this, or you may not. This is especially advantageous to you if you photograph scenes of high to extreme contrast and brightness range.
Thank you. That is what I remember Per saying.
But I cannot get any fully scientifically tested [with proper controls] results stating that staining is either good or bad. Most threads that try to thrash that out get into flame wars and I stop reading them.
Steve
I think the blown-out highlight issue is usually overstated. I have seen many prints made with tanned negatives, and have never noticed the highlight detail and gradation to be more impressive than with a well controlled non-staining developer. For anyone interested in some examples of what can be achieved even with a standard PQ developer, I strongly suggest looking at John Sexton's powerplant and Hoover Dam pictures from his Places of Power project. Many of the negatives were made under extreme contrast conditions, with ho hum TMAX RS developer, more dilute than usual and with reduced agitation, and I have never seen a longer tonal scale, nor better highlight detail and gradation than in those prints.
Stand development techniques, including those with tanning developers are not just for highlight control. In fact there is often less compensation than one might expect. It does however produce a unique tonal scale and more pronounced edge effects, all depending on the film-developer combo. I think Steve Sherman uses stand development quite a bit with ULF. Can't remember if he uses Pyrocat or a Pyro developer.
I'd just add that if Sirius Glass hasn't printed stained negatives before, it can take a little getting used to. So it might take a little practice before you can really decide whether or not to stick with the staining developer. The same goes for evaluating the negatives visually. You might look at the stained negative while it is drying and think you failed because it looks a little thin and low in contrast. That's how they are supposed to look. The printing paper sees the negative differently than your eyes so you really have to print them.
...You might look at the stained negative while it is drying and think you failed because it looks a little thin and low in contrast. That's how they are supposed to look. The printing paper sees the negative differently than your eyes so you really have to print them.
Does this men that you cannot evaluate them with a densitometer?
For most stained negatives you need to set a color densitometer to the blue channel, or use a blue filter on a B&W densitometer. You have to think like your printing paper when measuring densities. There is less silver density in stained negatives than normal negatives, but there is also stain density. If you use a regular white light densitometer it will therefore read less density than your paper will "see" (ie the negative will print with more contrast than you expect). The printing paper sees both the silver density and the stain density as additive. This is why a properly processed Pyro negative looks relatively thin and low contrast to the eye, but will print with higher contrast. It takes some getting used to.
The densitometer stuff can get more complicated unfortunately depending on whether you use graded or VC paper, and also depending on what kind of staining developer you use since different developers can produce different color stains. They can range from greenish brown to yellow-orange.
Visual evaluation of negatives (silver density vs combined silver-stain density) is one thing, printing contrast (in particular, local highlight contrast) is another.
When visually evaluating a normal pyro negative it will look thinner and lower in contrast than we might be used to seeing with a non-stained negative, because we're looking at silver density and not including the stain density in the visual assessment. Stain is proportional to the amount of silver halide reduced, meaning in highlight areas a fair amount of density when printing is coming from the stain. So what I'm saying is that if you look at the negative, the highlight areas might look comparitively thin (ie overall contrast looks low) while in printing the combined optical/spectral density of the silver and stain might be normal. So all we're talking about here is the fact with a pyro negative the density is a combination of silver and stain.
The issue of printing contrast, what filters to use is less straight forward and really just takes experimentation. The reason is that filters increase or decrease contrast by the same amount everywhere, while stain works proportionately. That's why many people say pyro negatives are easier to print when there is delicate highlight detail to render. Vs printing a non-stained negative, the stain reduces local contrast (ie compresses tonality) increasingly as density increases, so the stain acts like a built in variable compensating contrast reduction filter. It's like having a yellow-type filter that acts more on areas of higher density than in thin shadow areas.
The situation is further complicated by the type of paper. Typically pyro negatives will print with higher contrast on graded paper than VC paper since VC papers have a broader spectral sensitivity.
Wait a minute... is this a test? You've got way more experience that I do! I'm suspicious.
Not sure there is a straight answer since the imagewise stain acts as a variable filter, reducing contrast preferrentially in the highlights vs a standard printing filter that acts uniformly.
What I would say is that you'd typically want to give a pyro negative more development if you're planning to print on VC paper, than if you were using graded paper since the filtering effect of the stain is more pronounced with VC papers. This is why some folks advocate staying away from say small format pyro negatives with VC paper - because you need to give fuller development which counteracts the grain masking effect of the stain.
I keep hearing conflicting answers on staining.
One camp with Per, staining is proportional to exposure, use it.
The other camp with Sandy King [correct me if I am wrong], staining is uniform like a fog, do not use it.
Stain is proportional to the amount of silver halide reduced, meaning in highlight areas a fair amount of density when printing is coming from the stain. So what I'm saying is that if you look at the negative, the highlight areas might look comparitively thin (ie overall contrast looks low) while in printing the combined optical/spectral density of the silver and stain might be normal. So all we're talking about here is the fact with a pyro negative the density is a combination of silver and stain.
The issue of printing contrast, what filters to use is less straight forward and really just takes experimentation. The reason is that filters increase or decrease contrast by the same amount everywhere, while stain works proportionately. That's why many people say pyro negatives are easier to print when there is delicate highlight detail to render. Vs printing a non-stained negative, the stain reduces local contrast (ie compresses tonality) increasingly as density increases, so the stain acts like a built in variable compensating contrast reduction filter. It's like having a yellow-type filter that acts more on areas of higher density than in thin shadow areas.
The situation is further complicated by the type of paper. Typically pyro negatives will print with higher contrast on graded paper than VC paper since VC papers have a broader spectral sensitivity.
I have the same results as you, regarding the filters or contrast needed to print pyro negs, I have found a whole grade increase starting point.
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