not yet....lucky i even got these posted....been real busy...:)
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Pyrocat HD is said to be of reduced toxicity.
There have been many posts re: toxicity of pyro, and some tend to extremes.
I don't want to re-open freaking out over chemicals, but I would like a realistic assessment of precautions , if any. I'd do 4-6 rolls of 120 in SS tanks, with a little inversion agitation. The tanks always dribble, and I rinse my hands after I agitate now [ Xtol, fix etc]. Are nitrile gloves de riguer for men well beyond their child bearing years?
eddie? Sandy?
And I won't say, later, "But he told me to" if you think barehanded tank technique is of low risk.
thanks
Ed, a few drops or splashes of Pyrocat-HD on your hands are not going to cause a problem. Merely wash it off. Just don't drink the stuff.
It doesn't taste very good, anyways.
http://www.kennethleegallery.com/ima...rum/img202.jpg
Sinar P, 240mm APO Nikkor
4x5 TMY, Divided Pyrocat HD
Here's another one from the same batch, developed in Divided Pyrocat HD.
It was necessary to add overall contrast to the image, but it was wonderful not to have to even remotely worry about losing texture the high values.
I can't decide which one I like better: DD-23 or Divided Pyrocat. I guess I'm.. divided :rolleyes:
I think the risks involved with both pyrogallol and pyrocatechol in developing film have been greatly exaggerated, and sometimes distorted. If you mix solutions from powder with either chemical wear a mask and work outside or in a well-ventilated room. After that, wear gloves if you develop in trays. The solutions used in developing are very dilute and should not pose any risk in normal use.
BTW, hydroquinone is in the same family of chemicals as pyrogallol and pyrocatechol and is only slightly less toxic. It is used in a wide variety of film and paper developers but you rarely read anything about its toxicity.
Folks who are concerned about the toxicity of developers might want to use Xtol or some other ascorbic acid based developer.
Sandy
Jay... I'm sure there are threads dedicated to film development aimed specifically for best scanning. Any idea where some of those threads are?
I removed sulfite to get better edge sharpness, acutance.
And bias my agitation pattern the same way.
You can improve the results of D23/2 bath. I don't know whether it matches up the pyro.
bob
BTW, hydroquinone is in the same family of chemicals as pyrogallol and pyrocatechol and is only slightly less toxic. It is used in a wide variety of film and paper developers but you rarely read anything about its toxicity.
My guess is that many routinely used household cleaners, are more toxic than what we use only infrequently in the darkroom.
Mike - If you are going to scan, learning about compensating development as a way to simplify your "image capture process" make a lot of sense. In my analysis, it has made shooting film make sense. Here are three information sources that I would suggest...
- Two-Bath Development: Exposure and Development Strategy for Scanning, by Sandy King, published View Camera, July/August 2008.
- Joseph Lipka on Divided D-23
- Search for the term "diafine" at the figitalrevolution.com website, go the last article on the last page of search, and start there. This first of a series of articles on the topic that starts with this article/video: Processing Black and White Film for Scanning – Diafine and TX!
Thank you, Jay. :)
Changed my recipe for Compensating Pyrocat-MC from 1:20 dilutions to 1:10 dilutions for both Part A and Part B. I have reused the 1 liter of each developer to process three drums of 5 8x10 sheet of film (total of 15 8x10 sheets of film). And, I suspect that I could use it for four drums (total of 20 8x10 sheets of film).
Here's my revised recipe:
Films: Efke 25 exposed at ASA 25 and Ilford FP4+ exposed at ASA 100
Developer: Pyrocat-MC, Part A at 1:10 dilution Part B at 1:10 dilution
Developer and Presoak Temperature: 75 degrees F
Presoak: 5 minutes
Development Times (both films): (5 minute presoak) Part A: 5 minutes and Part B: 5 minutes
Ilford FP4+ @ ASA 100:
http://monkeytumble.com/tonopah/imag...91115_0002.jpg
EFKE 25 @ ASA 25:
http://monkeytumble.com/tonopah/imag...91121_0001.jpg
EFKE 25 @ ASA 25:
http://monkeytumble.com/tonopah/imag...91121_0003.jpg
A question please:
My developer baths got rather cold in my darkroom, like 63 degrees - but I didn't realize it. Watching the development process with my Infra Red monocular, I noticed that after 5 minutes in Solution B, the negative was really under-done. The low values were transparent, even though I placed them on Zone III.
In desperation, I rinsed the negative, and put it back into Solution A for a few minutes, and then back into Solution B. I noticed real improvement in the low values, and no further development in the high values.
Trying to reap additional benefits in the low values, I tried it again - but started to notice overall "fog" or density, so I decided to quit while I was ahead.
Is this a viable technique ?
I for one would be elated if your redevelopment technique worked. Have you scanned the negative and confirmed that the highlights did not block-up? If the highlights did not block-up, do you have a plausible theory why they did not, e.g., "tanning" of the gelatin so that further development in the highlights is severely retarded?
The negative is in the wash. I'll let you know.
I made a second shot, but haven't developed it yet. I thought I'd wait and see what the sages have to share :)
Ken,
I think it is a viable tecnique for those who do development by inspection with IR device.
However, the low temperature will limit how much of Solution A (the reducer) a film can absorb, which is the limit to highlight density. As I would have guessed your rinse and repeat technique increased shadow density somewhat but Solution A appears to have been just too cold to allow good absorption of the reducer. I recommend development at 75 degrees F with divided Pyrocat-HD.
Sandy
Thanks ! That makes good sense.
For the record, the film is 5x7 Ilford FP4+.
On the left is a "proof" scan of the 5x7 negative. On the right, cropped, toned, and adjusted a little. (Not the greatest photo in the world, but an exciting scene to encounter and photograph).
The subject contrast was high, and a yellow filter + polarizer was required to bring the sky values to look normal. Shadows are blue, and darken with warm filters.
Pyrocat 2-Bath compensation has definitely come to the rescue. The shadow areas which appear as Zone IV on the left, were Zone II and lower at exposure time. The high values on the distant garage door, fell on Zone IX and higher, but in the negative, they have full texture.
The only problem is a bit of uneven development, apparent in the sky - I presume due to the inadequate absorption of solution A.
I soaked the film for 3 minutes, and gave intermittent agitation.
With the second negative, I'll make sure the temperature is right, I'll bump up the soak to 5 minutes, and... give continuous agitation.
Thanks Sandy !
Ken,
The proof is in the pudding - The technique worked.
I think Ansel Adams discusses a similar technique in "The Negative" albeit without the viewing device.
Glad you are enjoying the 2 bath technique.
I think it worked this time - thanks for your help !!
http://www.kennethleegallery.com/ima...rum/img045.jpg
Buckland, Massachusetts
Kodak 2D, 300mm Fujinon A
5x7 FP4+, 2-bath Pyrocat HD
I have being thinking all morning about how to develop my contrasty FP4 negative today, and wolla, this thread came to the rescue! :D:D
I have some pyrocat MC and will give it a try tonight, thanks a lot guys.
Alex W.
Alex -
Just to be clear: The photos from earlier in the thread, were purposely over-exposed: The negatives were given enough exposure to place the shadows into the printable range, and the high values fell far beyond where any standard method would result in printable values. The 2-bath developer rescued the high values, not the shadows.
The photo I just posted, is a bit different. It was exposed normally, not over-exposed. The low values didn't get enough exposure, and the high values fell a bit too high. The 2-bath approach did not help a lot with the shadows, but it did help a little. It did keep the high values within printable range, and thus saved the image.
Try a test negative first. Don't experiment with an important negative, or a whole set of them, until you've got things working to your satisfaction.
Thanks, Ken, the pictures I took this time is not very serious. I have four negatives shot at the same scene, I will do one first just to see if I like it or not.
Alex W.
Good - I was worried.
One of the great things about real 2-bath formulas, is that they last long enough for you to evaluate the results and re-use. Very cool.
Wow!
Can't thank Ken and Sandy enough!
I was just procrastinating with an assortment of 120 films and spent last nite re-reading some of the old posts looking for pre-soak info and found none, and had decided I didn't need to. Meantime I finished some 2 reel sewer pipe tanks, hoping to conserve chemicals and avoid knocking them over in the dark
And I like the barn pic too.
Ooops- one more question: "Lots of" and "continuous" agitaton- is that for ALL three?- , A and B as well as pre-soak?
regards
Ed
Thankyou again- I see I almost totally misunderstood
Ed
hi, guys,
I finally developed my negatives using Pyrocat MC 2 bath method.
Here is how I did it.
pre-soak for 3 minutes
solution A (1:20) for 5 minutes
solution B (1:20) for 8 minutes
rinse with water for 3 minutes
fix in TF-4 fixer for 5 minutes
everything is done on a roller and the temperature is 75 degree.
The image has a wide range, I placed the shadow at zone 3, some of the dark areas were placed at zone 2 and 2/3, I think I should give it more exposure because the negatives are a little thin. They scanned pretty well through.
Here are a couple of images.
http://www.pbase.com/highpeak/image/121638553.jpg
http://www.pbase.com/highpeak/image/121638555.jpg
I really like how this developing method worked and I will use it with my negatives for the night scene.
with how well it's holding the highlights i think you could have placed the shadow at zone 4. talk about a looooong tonal scale.
i really love that second image.
Thanks Jeremy and Sandy.
I have been using Pyrocat MC for a while now, didn't know it can do a trick like this until now :)
Hats off to Sandy again for developing such a wonderful tool.
Alex W.
Here's another experiment: Clouds and Shadows at the same time.
The lower portion of the building is in shade, while late afternoon sunshine strikes the top of the building. In the distance, the sky contains soft clouds, also lit by direct sunlight.
Until recently, I would have admired the scene, but never wasted a shot on it. An Orange filter to give separation to the clouds ? Sure - but the shadows are already dark, and only illumined by blue light.... Foregettaboutit !
This time, I decide not to use a filter at all, and see what Divided Pyrocat HD will yield. Over-exposing even the deepest shadows, the clouds fall on Zone XV and higher.
On the left is a proof-scan of the negative. On the right, some contrast has been added in Photoshop. Can you believe it ? We have to add contrast.
I'm beginning to wonder if filters are even necessary, when shooting outdoors.
http://www.kennethleegallery.com/ima...m/two-bath.jpg
Your experience is consistent with mine. The question that has lurked in my mind is... are there situations where this development results in an unusable negative, i.e., will using a development that retains information for thirteen or more stops loose tonal separation. Thus far for myself using this development, the answer is no, even with my (very) limited repretoire of scanning and image manipulation skills.
Alex,
Are you agitating the film at all or just straight soaking in both baths?
Andrew,
Think of the specific functions of both baths.
In Solution A the emulsion soaks up the reducer. How much it can absorb is determined by temperature (at higher temperatures the gelatin swells more, allowing more reducer to be absorbed) and agitation (more agitation also means more reducer being absorbed. However, there is a limit to how much reducer the gelatin will absorb, and that limit is usually reached at about five minutes at 75-80 degrees with constant agitation. However, five minutes at 75 degrees with intermittent agitation gets you to about 95% of the maximum so that is where I usually work.I
In Solution B the development takes place and agitation is more critical at this stage for the same reason it is critical with regular film development. If there is not enough agitation you will get bromide drag and uneven development. I recommend very vigorous agitation for the first minute of development, and then 10 seconds of agitation every minute thereafter. However, if you get any uneven development with this method you should go to constant agitation. Time in Solution B determines film speed, to a point, and extending time from five to ten minutes will probably give a little boost to shadow detail with no down side, assuming you keep good agitation.
In general this method of development is really hard to beat, especially for scenes of great contrast.
Sandy King
http://www.kennethleegallery.com/ima...m/img201dp.jpg
Patrick
Sinar P, 300mm Fujinon A
5x7 HP5+, Divided Pyrocat HD
To render the scene inside the room, a 6-second exposure at f/16 was required. The darkest values on the jet-black dog, were actually too low for my light meter to measure. The scene outside the window - bright sunshine on foliage - fell on Zone 14.
[QUOTE=sanking;587090]Andrew,
Think of the specific functions of both baths.
In Solution A the emulsion soaks up the reducer. How much it can absorb is determined by temperature (at higher temperatures the gelatin swells more, allowing more reducer to be absorbed) and agitation (more agitation also means more reducer being absorbed. However, there is a limit to how much reducer the gelatin will absorb, and that limit is usually reached at about five minutes at 75-80 degrees with constant agitation. However, five minutes at 75 degrees with intermittent agitation gets you to about 95% of the maximum so that is where I usually work.QUOTE)
Sandy,
How does agitation increase absorption? How do you measure absorption? What is the goal in maximizing absorption?
Don't want to geek-out too much here, but the in the world of chemical engineering, the amount of developer absorbed into the emulsion is a mass transfer process. The mass transfer process, in this case the transfer of chemicals in Solution A into the film emulsion, is driven by the concentration of Solution A first and foremost. As usual, for a given concentration of Solution A, Sandy's information above is correct.
What is the point?
If you find that you need more development, increase the concentration of Solution A and Solution B and keep all the other development variables the same...
I had been using Pyrocat-MC at 1:20 dilution for both Solution A and Solution B. And, I found that I was not getting sufficient development in a few cases and generally could use more development. I now develop all my film with a Jobo processor at 75 deg. for 5 minutes using Pyrocat-MC at 1:10 dilution for Solution A and Solution B. This development has worked well for everything that I've tried thus far. I do develop different films together, e.g., TXP, FP4+, and Ekfe 25, that are exposed at the manufactures' rate film speed, and everything comes out well for scanning.
At any given temperature and concentration maximum transfer of reducer into the emulsion is increased by agitation.
With any given film the more reducer you can get into the emulsion the higher will be the final contrast, keeping all factors equal with development in Solution B.
The goal in maximizing absorption is to adjust for the different absorption potential of different films, other factors kept the same. For example, if you develop TMY-2 the same way you develop Fuji Acros the former will have lower contrast than the latter. If you wanted to develop TMY to the same contrast as Acros you would want to increase absorption by either, 1) increasing the temperature of Solution A so the gelatin will aborb more reducer, or 2) increase the concentration of Solution A, say from 1:20 to 1:10, or 3) increase frequency of agitation.
In theory you could check for absorption by weighing a sample of film before and after it has been in Solution A but you would need a scale capable of measuring very small amounts. I actually do this with carbon tissue to determine absorption of dichromate but with film I don't believe my instruments have enough precision, so I test empirically by testing two samples, one with agitation and one without, then develop the two the same in Solution B. The only thing that could explain an increase in contrast, if you observe it, is the increased agitation.
Sandy
Thanks -
I just read the recommended procedure on Pyrocat as a Two-Bath Developer on Pyrocat HD site.
I had missed a few important points, namely
- 1:10 dilution
- 5 minute pre-soak
- 6 minutes in Part A
- 5 minute post-soak in water
Jay,
Varying the concentrations of the baths makes perfect sense to me, and is the approach I use when using Hypercat as a 2-bath developer. I use Hypercat A solution 1:10, and use a 1% solution of TSP as my B bath. My development times are much shorter than those reported here; I develop 2 min in A, and 1 min in B, at 70F. This works very well for me, even I'm very flat lighting. Is there some advantage to using a more dilute solution with longer development times?
The purpose of the longer development time of Solution A is to get 100% absorption, or close to it, without having to worry about temperature. You could also run Pyrocat with much shorter times if that is considered important but there would be some difference in final contrast between 5+5 and 2+2 depending on temperature. Development in Solution B is almost instantaneous as the image comes up immediately (as in pt/pd printing for example) but you can coax a bit more shadow detail from the negative with longer development times. Bottom line is that you won't see a lot of difference in final result between 2+2 and 6+6 but the longer times even out results without having to worry about temperature between 70F and 80F.
Sandy
Sandy,
I'm afraid I still don't understand how agitation increases absorption, but I don't understand a lot of things.
It seems to me you're saying contrast is controlled by: time, temperature, concentration, and agitation in the A bath. If this is true, it seems to contradict a lot of the claims made for "automatic" 2-bath development. To develop to a predictable contrast requires a strategy, and considerable testing. Assuming development time in the B solution is non-critical beyond a minimum time for full development, one should still find it necessary to find the correct combination of time, temp, concentration, agitation in the A bath to achieve the desired contrast. What do you consider the best strategy for adjusting contrast? One strategy is to keep temp, concentration, and agitation constant and adjust time in the A solution. This strategy depends on the absorption rate of the film, which should remain consistent for any given film. This seems like a better strategy than adjusting the concentration of the A bath and keeping the absorption time constant ( maximum), because different images present varying demands on developer, ie a high key image requires more developer than a low key one. I don't think agitation offers much range as a contrast control, but temperature of the A solution might. It would make an interesting experiment, comparing the relative effectiveness of temperature v time as contrast controls. Time is almost certainly the most convenient control, but temp is not terribly inconvenient, especially when using automated processors. Still, if I was a betting man, I'd put my money on time in the A solution as the simplest, most effective contrast control.
There is definitely a lot of misinformation out there about two-bath development but I never worry about that because one can just step over all that and test to determine what is right and wrong. Another issue that needs to be clarified is that there are different kinds of two-bath developers. One kind is Diafine where all of the development takes places in Solution B (Pyrocat and I presume Hypercat are in this category), another kind is divided D23 where considerable development can actually take place in Solution A.
My own approach to two-bath development is to use it when your work flow does not require that negatives be developed to a certain contrast. If you scan it does not make a lot of difference whether your negative has a CI of .45 or .65, or even more extreme contrast than that. If you need to develop negatives to a specific contrast you are better off following Zone or BTZS type procedures with traditional one bath formulas.
If you must for some reason adjust contrast with two-bath developers the easiest way to do so is by adjusting the dilution of the reducer in Solution A. However, within limits you can also increase or decrease contrast by type of agitation in Solution A, and/or by length of time in Solution A, or by the temperature of the solution. In the article that I published in View Camera a couple of years ago I found that with most films using both D23 and Diafine it was possible to approximately equal contrast with rotary/continuous development compared to normal intermittent development by using a weaker dilution, say 1:120 instead of 1:10.
The amount of control possible with temperature and time is limited by a finite amount of solution that the gelatin can absorb, and heating it more and/or leaving the film in the solution for a longer period of time, will not in result in more absorption.
All that said, if one has a need to develop film to a specific CI I would recommend traditional one bath development with time and temperature control, not two bath development.
Sandy King
http://www.kennethleegallery.com/ima...rum/img272.jpg
Patrick
Sinar P, 450mm Fujinon C
5x7 HP5+, Divided Pyrocat HD
http://www.kennethleegallery.com/ima...m/img271dp.jpg
Lake, Massachusetts
Sinar P, 450mm Fujinon C, Light Yellow Filter
5x7 HP5+, Divided Pyrocat HD
There are all kinds of scenes that I now look forward to shooting.
They posess a special richness and subtley of tone, but were previouly out-of-bounds because of their impossible contrast range. Now, they are laughable.