Originally Posted by Ronald Moravec
Unless there's a lot of general stain or fog, which *can* vary considerably from one developer to the next. Caffenol and some pyro formulae, for instance, produce significant general stain, which will increase overall printing time. Old film can have some level of silver fog in many developers, even when the final contrast (measured from base+fog) is correct. Anything that increases the Dmin will increase printing time (assuming same light, magnification, and aperture), because it simply takes longer to get a max black on the print.
Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.
I will not stick my head in the sand and not try your suggestion, If it is better I will obviously switch.
I can relate a bit of a humouros story revolving around film developers and different films. When I first opened my shop I decided to do a lecture with the PPOC (proffesional photographers of Canada). This lecture was to be at my shop and I confirmed 50 people. The topic was film and different developers . I got all the major suppliers to provide me with buckets of their film and I hired a studio photographer to shoot all the film and I processed them in wads of different, developers to recommended times. I then printed all the prints to a pleasing common balance.
Here is where it gets painful for me, As I printed the week before I had no chance to gracefully cancel the lecture. Why would I cancel you say?
Every print did look the same there were no major differences to be seen, yes some improvements but basically I was now forced to stand in front of 50 photographers and show them the differences. This was 1993 and since I have been very loyal and consistant with my developer choices.
At our shop D76 and Pyro are our main developers closley followed by tmax and then rodinal and microphen.
Learning a new developer takes me a long time , but as you and others suggest , it may be worth the time.
I will indeed try an increase in A as you suggest.
The problems with Pyro and roller transport is well recorded at our end. It took us numerous film runs to get all the bugs sorted out.
To say it does not work , to me is not valid as I have processed a lot of film with this method as well I have printed many shows over the years with this film. The prints that I have made are by my humble estimation good enough to hang, I have seen many others work in gallerys over the years and feel confident enough to use this film developer combination. I do promise to try pyrocat face to face with Mr Hutchings formula and I will make side by side prints to compare. I do not want to go into all aspects of our learning curve with this Mr Hutchings developer but I may be of the mind to not tamper with a good thing, and adding a new developer to our workflow is a daunting task as I cannot run my clients film as tests.Therefore I will need to do this on my own with my personal projects rather than clients. And this will take time.
Bob - I would like to suggest that you get a nitrogen tank with regulator and some 3/16" tygon tubing and make a nitrogen purge system for your Jobo. I did this recently and I found it not only extended the developing capacity of the PMK, but it also shortened my development times. Sonce you are running a commercial lab, this would in the long run save you time, money, and increase the flexibilty of your process.
Originally Posted by Bob Carnie
As an example, I used to process at 24C with 1.5 L of PMK and my developer pretty much tapered off around 15 minutes, just as you have found. My Normal time was about 10 minutes. By setting up the nitrogen tank (see the description in the Book of Pyro), I run the nitrgen into the 3010 tank and I have the nitrogen fowing at around 1L/minute. My Mormal Time is now 7 minutes.
I start the flow at the beginning of the run and I do a several minute water bath/soak on the film before the developer step. This allows the tank to be pretty much flushed out of any air. The developer before I started using the nitrogen flow would exit the tank looking black, and now it is a pale orange color.
Using a nitrogen tank sounds complicated I'm sure, but it is really easy to do.
Kirk - www.keyesphoto.com
We are using two Alt2300 . the problem is that the chemistry is pumped automatically by the processors.
Do you think if we took off the tank after the pre soak. then manually pump in nitrogen , then put the tank on the machine and start the developing stage, we would in effect mimic what you are doing.
I imagine you are using a cpe or cpp system where you fill the drum manually then add the nitrogen?
I am concerned in adding nitrogen after the developer is in the tank, the time to do so would be a problem as the first stage in developing is critical, causing
disastorus results if agitation is not started immediately.
We do use a two 7min stage dev with 1litre per stage to help with the exhaustion problems.
I would indeed be very happy to get pyro development under 10min as you suggest.
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Originally Posted by Bob Carnie
Just to be clear, I am not one of the persons who says that PMK will not work with rotary processing. But there are definitely problems that must be overcome. You don't have to search too deep into the literature to know that when PMK first came out there were numerous complaints from persons who experienced problems when using it for rotary processsing, including uneven streaking, staining, and heavy general stain. There are solutions to these problems, such as splitting the working solution into two parts, as you do, increasing the amount of A solution, or adding a small amount of either ascorbic acid or suilphite. But if you don't do anything you are likely to get more general stain from oxidation, especially with long development times. The advantage of both Rollo Pyro and Pyrocat-HD with rotary processing is that you don't need to do any of these things to get good results.
Last edited by sanking; 06-16-2005 at 09:01 PM. Click to view previous post history.
I will pile on and say I used a jobo and PMK for several months and I could never could make the same quality neg I could in a tray development enviroment. After trying all the known adjustments to PMK (the ones Sandy mentioned in the above post) I sold the jobo for more than I paid but now that I use Pyrocat-HD I wish I had the jobo back. I was committed to PMK for years (over 8) and I can say without a doubt that Pyrocat-HD suits my film developing purposes now (lgformat).
Originally Posted by Bob Carnie
I've never seen an ATL processor so I can't give any specific instructions. Yes, I'm using a CPA-2.
Here's some more specifics on what I did - I bought a length of 3/16 (5/32 maybe) tygon tubing (Tygon is pretty resistant to chemicals). I connected it to the nitrogen regulator outlet, and then threaded the other end into the drain tube of the Jobo lift. If you look down the throat of the lift drain tube, you will see an air breather tube in there as well to allow air to enter the drum while the liquid comes back out the drain. I just ran the Tygon down into the lift drain along side the breather tube. It's a little tricky getting the tubing to make the final bend into the bottom end of the lift drain - a small screwdriver or something stiff may help to direct the tubing the right direction. Once I got it through, I pull it so a couple of inches of tube are showing. I just tuck that exposed tubing into the drum as I put the drum on the Jobo.
So now I have this tube sticking into the lift fill opening, and it looks like it may interfer with the actual use of the lift when dumping the chems - it does a little, the lift will not go quite as high, but it is more than sufficent. The tygon gets a little pinched when the lift is up, but the tubing is soft and flexible and it works fine.
Before I put the tube into the lift, I adjusted the nitrogen flow to about 1 L/min by taking a bucket and filling it with water and then putting an 1 liter graduated cylinder filled with water to the top of the cylinder into the bucket upside down. Place your hand over the top of the clyinder to hold the water in place as you quickly invert it and then put it into the bucket. Do this quickly and almost all the water will stay in the cylinder. Then place the Tygon tube under the end of the cylinder and let the nitrogen flow into the cylinder. You can adjust the flow to get it somewhere around 1 L/min. Or you can get a flow meter to connect inline to make direct measurements. But the bucket method is cheap and easy - it may take a few trials to get it where you want. The actual pressure is so low that it doesn't register any pressure on my regulator when I have the flow set this low. Don't touch the regulator once you get is adjusted.
So for you - how does the ATL dump the chemistry? Does it lift the drum up like the CPA or does it pump it out somehow? If the ATL dumps the chems by lifting the drum, then you probably have a drain tube that is about as large as the opening on the drum lids. If it does, you may be able to thread a tygon tube into the drum drain, maybe from your floor drain? Or make a modification to the drain plumbing somewhere closer to the drum.
Or - here's an idea- you could try just flowing nitrogen into your drain line. Since the drum is fairly well sealed to the machine, everytime you pumped liquid out of the drum, it would pull some nitrogen into the drum, as well as keep a blanket of nitrogen above the drum to exclude any air/oxygen from getting into it.
I hope you'll see some way to apply these ideas, as I think it really works well, and as I said, the materials aren't that expensive. You can get an N2 regulator for around $40, and and tanks are not too expensive either. And a large tank should last quite some time at a flow rate this low. And you can turn the gas off (use the tank valve instead of touching the regulator once you get the flow adjusted) when you have dumped the PMK - you don't need the nitrogen for the rest of the run.
If you have any other questions, please ask.