From: Jeff Buck (jeffbuck@swcp.com)
Date: 11/13/02-08:29:26 AM Z
Where are people on the list getting what integrators and how are they
installed? -jb
At 11:10 PM 11/12/2002 -0600, John Campbell wrote:
>Sandy,
>
>Which integrator (manufacturer/brand/model number) is in your configuration?
>
>TIA,
>John
>
>www.photogecko.com
>
>
>
>----- Original Message -----
>From: "Sandy King" <sanking@clemson.edu>
>To: <alt-photo-process-l@skyway.usask.ca>
>Sent: Tuesday, November 12, 2002 10:47 PM
>Subject: Re: Consistency Is No Hobgoblin
>
>
> >
> > Jeff wrote:
> >
> >
> > I am not saying that the variations in temperature and humidity are
> > not an issue. However, I will say with absolute certainty that 2-3
> > minute warm up time is not sufficient for most commercial metal
> > halide lamps to reach full output. With an integrator you calibrate
> > the unit to reach a certain output, which in my case I have set to
> > 100 when the the unit of operation is approximately one second. At
> > 2-3 minutes my unit, as measured by the integrator, has only reached
> > a reading of 20-30 units, that is, less than 25% of full output.
> > Obviously if your exposures are in the 10 minute range and you begin
> > them at 2-3 minutes of turning on the light, you should be seeing
> > significant variations in printing density, irrespective of any other
> > factors.
> >
> > Sandy King
> >
> >
> >
> >
> >
> >
> >
> > >Clay & Sandy: Thanks for the suggestions. As you know, I have a
> > >metal halide HID. I don't worry much about timing the exposure,
> > >because they run 6-8 minutes typically and I don't see how the 2-3
> > >second fudge in my crude timing system can make any difference. The
> > >intensity of the lamp is another matter. When I got the thing last
> > >spring, I followed leads to get an integrator, but pretty much
> > >crapped out when the glass-virtuoso guy proved no help. On the
> > >other hand, looks like I should be doing a longer warm-up. I've
> > >been doing 4 minutes because the electrician said 2-3 minutes would
> > >be plenty. As for the quiet time around the house, I can manage
> > >that sometimes and I try to.... Say, are you guys saying that the
> > >variations in temp and humidity I noted are probably not at issue?
> > >-JB
> > >
> > >At 11:04 PM 11/12/2002 -0500, you wrote:
> > >
> > >>Clay wrote:
> > >>
> > >>>Jeff:
> > >>>
> > >>>What are you using for your light source? And how are you timing
> > >>>it or measuring it. I find I get pretty consistent results with
> > >>>the same materials and ambient conditions... But I'm using a Nuarc
> > >>>most of the time.
> > >>
> > >>
> > >>When using any UV light source without an integrator one is almost
> > >>certain to observe some small differences in print density, even
> > >>when all other things are held to absolute consistency. I find this
> > >>to be true with both my bank of BL tubes and with the HID lamp when
> > >>used without the integrator.
> > >>
> > >>If one must work without the integrator it is best to do so when
> > >>the house is relatively quite and there are no large and sudden
> > >>current drains. Also, for maximum consistency all light sources
> > >>should be allowed to warm up for a few minutes before exposing. Two
> > >>to three minutes is enough for fluorescent tubes, while HID mercury
> > >>vapor and metal halide lamps need from 5-8 minutes to reach maximum
> > >>output.
> > >>
> > >>Sandy King
> > >>
> > >>
> > >>>
> > >>>Clay
> > >>>On Tuesday, November 12, 2002, at 08:58 PM, Jeff Buck wrote:
> > >>>
> > >>>>Actually, it's the tendency of a phenomenon to recur in the same
> > >>>>form.... Anyway, after doing platinum/palladium for about
> > >>>>fifteen months now, I find if very difficult to achieve. I
> > >>>>arrive at a print that is satisfying. I want to repeat it. So,
> > >>>>I use the same paper, the same chemicals (plain FO, pure
> > >>>>palladium, PO w/ sodium dicromate mostly), the same exposure, and
> > >>>>the same developer. As for ambient temperature and humidity, I
> > >>>>can get pretty close to repeating, especially this time of year
> > >>>>when I'm producing both artificially (by and large). Like the
> > >>>>last couple days, I'm printing this negative, and the temp is
> > >>>>between 65F and 70F, the humidity is in the range of 60% to 70%.
> > >>>>In each instance, the paper has been laying out in the area of
> > >>>>that temp and humidity for a few hours; it's a little "heavy" and
> > >>>>tacky to the touch. I guess I made four prints in these
> > >>>>conditions (I was double-coating Platine, if that makes any
> > >>>>difference). There were notable differences in the overall
> > >>>>darkness of the prints and in degree of contrast. Would you
> > >>>>expect discernible differences working within these variations in
> > >>>>temp and humidity? How do you measure the temperature of the FO
> > >>>>and platinum or palladium? I'm squeamish, maybe for no reason,
> > >>>>about putting a thermometer into a bottle of precious metal....
> > >>
> > >>
> > >>--
> >
> >
> > --
> >
> >
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