Do you have some reference times for fp4 or hp5?
That's an interesting looking formula, Jay. How bad is the fog if you leave out the BZT?
I see hypercat has a similar make up to the old windisch extreme compensating developer(in its use of catechol and sodium hydroxide). Have you thought of exploring its potential as an extreme compensating developer for those high contrast scenes where you don't want the highlights to block up but would also lke full shadow detail. Would there be anyway to make your developer less active or act as a compensating developer but with out the loss of filmspeed.
I did a comparison of Hypercat at 1:1:100 with Pyrocat-HD at 2:2:100. The dilutions were chosen to provide as close as possible the same amount of pyrocatechin in the working solution.
Film was FP4+. The negatives were exposed identically with a light integrator, and were developed together.
Analysis based on blue densitometer reading.
B+F Pyrocat-HD lower than Hypercat, 0.10 to 0.17
EFS Pyrocat-HD slightly higher.
Energy Pyrocat-HD higher, increasing significantly with time
These results do not appear to agree with Jay's findings, but I am confident that they are correct. I draw many conclusions from this test. If you have questions please let me know.
To understand the curves, as you go from left to right the data is 1) time of development, 2) EFS, 3) CI, and 4) value for SBR.
I won't comment on grain and sharpness at this time since this determination will require another test exposing and developing the film in the two developers for the same contrast. My personal opinion is that Jay's Hypercat is much improved over the older formulas that use pyrocatechin + sodium hydroxide, but it is no match for Pyrocat-HD, at least in the area of B+F, energy and EFS.
Should you trust my test results? You decide.
And BTW, regardless of what you think of the developers, you gotta love that long straight linear line of FP4+. The straight line of course in the film, but both of these developers are able to take maximum advantage of it. I mention this because some developers do not.
I also did a test with HP5+ in the two developers, with similar results.
Last edited by sanking; 05-21-2005 at 09:31 PM. Click to view previous post history.
In reply to your comments, in quotes.
“It appears that my developer works better for me, and yours works better for you. I don't know how to account for that.”
“How did you develop your film, and what do you mean by-" The negatives ...were developed together"?
The developing solutions were mixed from the same temperature controlled water, and the negatives were all developed together in individual tubes in the same temperature controlled water bath. It was an apples to apples comparison, if you understand what I mean.
“Could you post your data for HP5+”?
Yes, I will do that. I may be able to do it tonight, but if not will do so tomorrow.
"I don't need to "trust" your results, as I can perform my own tests in my own darkroom, but your results do provide a basis for comparison.“
Of course, you can perform your own tests. You can test until the world turns green. But if you are unable to get consistent results your tests are meaningless. I have absolute confidence tht if I do these same tests tomorrow, the results will be very close to identical.
(The HP5+ files are attached. They were set up for AZO 2 with a ES of about 1.65.)
Last edited by sanking; 05-22-2005 at 12:38 AM. Click to view previous post history.
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Seems fair to me.
Originally Posted by Donald Miller
Let's go for it.
Originally Posted by jdef
You don't seem to understand. There is no subjective step involved. There can be no bias in exposing film, reading step tablet densities, and plotting curves. You put the step table on the densitometer, take a reading, record it, and enter the value into the graphing program. When you have entered the 21 or 31 steps, and entered the value for process ES and flare, you hit enter and the program produces a curve. How do you figure I might apply bias to influence the program?
Now, if we were to evaluate our negatives in terms of grain or sharpness the element of bias would be more than possible. In fact, bias would be likely in my opinion, because this is a very subjective step and many people see what they want to see.
But to be more precise, my results are more than just my results. They are the result of the application of sound methodology and careful testing procedures, and the results of the test can be repeated with very close tolerance, either by me or by someone else with the proper equipment and understanding of good testing procedures.
The problem here is, simply put, you don’t have the skills to maintain consistency in your testing, and that is obvious from the inconsistent results that you yourself have reported.
Last edited by sanking; 05-22-2005 at 12:23 PM. Click to view previous post history.
I would offer to do it at no cost, but I can't promise a very timely turn-around time for it, it would be a month or two... It would be on FP4+ sheet film if that's acceptable.
Originally Posted by jdef
By the way, what happened to Donald's post from last night that Sandy quoted? Are posts just spontaneously disappearing?
That would be fine with me. I will send you the Pyrocat-HD and Hypercat stock solutions and you can do the comparison on FP4+. FP4+ is one of the best films for this type of comparison because it has a wide range of expansion and contraction possibility.
Originally Posted by Kirk Keyes
Given your experience in laboratory work I have a lot of confidence in your ability to establish the proper conditions for a reliable test. The keys of course are, 1) use film from the same emulsion batch that has been stored the same way, 2) exposures must be consistent to at least 1/10 of a second, 1/100 even better, 3) exact control of developer temperature is required, both intitially and over the duration of the time of development. I assume that you have step wedges that can be used for the test?
Just contact me by email at email@example.com and give me your mailing address.
If there is someone else out there with good control of BTZS type testing who might be interested in testing another film let me know and I will send you some of the two developers.
Thanks for the offer on the solutions. I just sent you my address.
Originally Posted by sanking
I propose that I use tray processing of 3 - 4x5 sheets in 8x10 trays, with these in a 11x14 tray water bath to help control the temp. Processing be around 20C - but identical for each run. I can use the same times that you did Sandy. Mild acetic acid stop bath, pH at about 5.5. Ilford Rapid Fixer at film strength.
I just received 2 - 25 sheet boxes of FP4+ from the same lot that I can use. I assume the boxes have been right next to each other form their entire lives.
I would use my Saunders 4500 fitted with an 80A filter to convert to daylight, a Stouffer 4x5TP step wedge, contact printed. I use a Graylab 900 timer with claims to be accurate to 1/60 sec. Exposure time will be 1 second. That should be more than precise enough.
Sandy - which step wedge do you use? I see you have 3 wedges with numbers on the margin on each edge and the middle of some of the 4x5 sheets you sent me last year. I assume you do this to check evenness, and it also allows you do have some neutral density between the wedges. You find this better than the full frame 4x5TP?
Are there any other conditions that anyone care to specify?