From: clay (wcharmon@wt.net)
Date: 11/25/01-08:12:31 PM Z
I've had the same problem with Rollo Pyro (ABC+) resulting in incredibly
long exposure times although I use mostly TMax 400 and TriX. I get a very
high base+fog using the technique outlined in the Weese article in Photo
Techniques with the Rollo Pyro. For what its worth, I DO NOT have the same
problems with Sandy's Pyrocat-HD, but do agree that adding an extra stop of
exposure (just in case) is a very bad idea with Pt/Pd printing in mind. In
fact, the whiz-bang analysis tools in the BTZS plotter program indicate that
my actual film speed with Tmax 400 and Pyrocat-HD is actually around ISO
600.
I have been advised (but haven't yet tried) that skipping the second, post
development metaborate bath with Rollo pyro will reduce some of the high
degree of overall staining you seem to be getting. I'm going to give that a
shot this week now that I have some time and curiosity to do a little
investigation into the staining problem. I'll let the list know if anything
earth shaking results. I CAN say that the Pyrocat-HD has pretty much solved
the problem for me though, and it seems to give all the benefits
attributable to a pyro developer (e.g. high acutance, great highlight
definition, actinic filtering for UV sensitive processes, and reasonably
short development times) without the high base+fog and toxicity. Check out
www.unblinkingeye.com for the formula. It is incredibly cheap and easy to
mix yourself.
Good luck. Just wanted to let you know that you are not alone in finding
this difficulty with Rollo pyro.
Best,
Clay
----------
>From: Jeff Buckels <jeffbuck@swcp.com>
>To: alt-photo-process-l@skyway.usask.ca
>Subject: Re: Dense or Density
>Date: Sun, Nov 25, 2001, 7:28 PM
>
>OK: I've been making the FO the night before and actually using it late morning
>or so the next day.... The ambient humidity lately has been 30 to 40%. Before
>coating, I humidify the paper (Platine) in front of a smallish sonic humidifier
>for about a minute. After coating, I dry the paper (cold air double window fan
>at four feet dries to 75% or so, then med-heat hair dryer till dry), then
>re-humidify as before, then expose. The range has been pretty good, but not
>great -- I'm not getting to real black black (brown brown). I used sodium
>dichromate just with this one print; mind you, the brightness range of the
>subject was a good stop short of normal. I exposed and developed normally,
>figuring to kick up the contrast a bit with the sod dichromate. This worked
>pretty good. It was not full range, but I intended the look I got (pretty much)
>from the get-go. Believe me, if the exp. time hadn't been 50 minutes, I
>wouldn't have thought there was a "problem"... I've only done two non-pyro
>negatives. The exposure times were well within normal ranges, around 5-7
>minutes.... Finally, these pyro negatives that have printed so slow in pt/pd
>are correspondingly slow on Azo. For this reason, I think we can eliminate bad
>FO or bad pt/pd or bad humidifying etc. ... I sure appreciate these responses.
>-jb
>
>Eric Neilsen wrote:
>
>> Jeff, There seems to be many things left unsaid by you about your whole set
>> up.
>>
>> FO should be well mixed and will take hours (pushing it) and a day or so to
>> fully dissolve. It will last many many months. Mixing it fresh is a
>> problem, not only to get it mixed, but weight properly the same for small
>> batches. If you are using AFO, that is a different animal.
>>
>> Are you drying your paper? dry palladium paper or one with a low RH is
>> slower than a humidified paper?
>>
>> Is the film printing full range? 80 minutes seems quite long. How much
>> dichromate in your developer? this will also slow your print times.
>>
>> What are your times for a non pyro negative?
>>
>> EJ Neilsen
>>
>> ----- Original Message -----
>> From: "Jeff Buckels" <jeffbuck@swcp.com>
>> To: <alt-photo-process-l@usask.ca>
>> Sent: Sunday, November 25, 2001 10:04 AM
>> Subject: Dense or Density
>>
>> > Hello from Albuquerque NM. This is my first posting to this fine
>> > list....
>> >
>> > I've started doing platinum/palladium. Have done two sessions in my
>> > newly up and running home rig. I'm excited by the results I'm getting
>> > but am plagued by preposterously long exposures. Here's what I do: I'm
>> > shooting FP4+ (5x7 and 8x10) @ EI 64, erring on the side of
>> > over-exposure. Nothing fancy as to reading; for the time being, to keep
>> > it simple, I'm just doing split readings (mostly between the darkest and
>> > lightest readings on the palm of my hand), leaving any particular
>> > contrast control to the printing stage. I'm developing the film in PMK
>> > for 12 minutes at 70F. All exposures, regardless. The printing is on
>> > Platine. I've done a couple prints with pure palladium, a couple with
>> > about 55/45 Pt to Pd, adding some contrast on one occasion with a small
>> > amount of sodium dichromate in the pot/oxalate developer. The color and
>> > contrast need tweaking but I'm happy with both. The exposure times are
>> > an outrage: From 20 to 80 minutes. I can live with 20, and I
>> > understand there's only 2 stops difference between that and 80, but most
>> > the exposures are over 50. The light source is a new "oven" from
>> > Edwards, which I feel is working correctly. Can anyone tell me if
>> > anything jumps out of the above procedure as the likely repeat cause of
>> > these pokey exposures?? I'd sure like to stick with Pyro and know that
>> > that is the principal culprit. But, you know, if I could just get to
>> > 15-20 minute exposures, I'd be satisfied.... Thank you.
>> >
>> > jeff buckels (albuquerque nm)
>> >
>> >
>
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