From: Steve Shapiro (sgshiya@redshift.com)
Date: 09/11/02-03:11:31 AM Z
----- Original Message -----
From: "shannon stoney" <sstoney@pdq.net>
Subject: printing with light bulbs; Swiffers
> My excuse for asking this question is that we discussed a month or so
> ago the fact that Weston printed with a light bulb. It was suggested
> that you could do this nowadays by using a 7 1/2 watt bulb and
> regular silver gelatin paper. I did that today, somewhat
> successfully, but the printing times were really short, like 8
> seconds. The light bulb is about 40" above the paper, as high as I
> can reach. IT's an unfrosted bulb. I had a reflector on it but that
> caused hot spots, so I took it off. How can I slow these times down
> to have more time to manipulate the print? These modern papers are
> shockingly fast! And their scale is shockingly short!
>
> The other burning question is: would Weston have used Swiffers to
> clean his negatives?
>
> --shannon
> --
>
It's fun reading all the responses that followed this original post.
Guesses, off the wall suggestions, in my experience; and good research on
the Cole Weston quotes.
First: For silver Gelatin contact prints use the FROSTED refrigerator 7 1/2
watt bulb at 36 inches. It is exactly 1/2 foot candle of light to the galss
on the print frame. BTW you only get newton rings if there is any amount of
moisture on the glass. From there you make the time work with that light.
If your exposures are too short, your negatives are too thin. Raise the
light in incriments of 12 inches at a time. (Please don't make me go into
the Coloumb quantim or the Hall effect) Take my word for it.
Cole wrote how he would raise the light by changing the bulb per his
father's notes to a 40 watt or 75 watt bulb, but that was as high as he ever
went.
Second: Using Azo paper ALWAYS use a 300 watt bulb, 36 inches from the
paper. Sometimes my exposures (that actually average from 12 secs on Grade
4 to 24 seconds on Grade 2) are as long as 124 seconds, but that's rare.
Some negaties made for L O N G platinum print times go as long an average of
104 seconds; and then I lower the 300 watt bulb to 24 or 18 seconds and
halve the time. Again, it's a principle in physics I can go into if your
having problems and wish to send me a print, but it's too much to write out.
Disasterous to wrap anything around modern light bulbs and equally a folly
to use a bulb that has the GE label on the top. But I was surprised to read
Michael Smith's post recommending a hood around the light. BAD IDEA. The
diffusion principle dealing with light can fog the paper or benifit the even
dispersal of the light that hits the paper. A hood WILL create hot spots on
the print.
Using Amidol formulas, and I recommend the Weston Kit from the
Photographers' Formulary to begin with . . . . What formula do you plan to
use, Shannon? . . . remember Amidol brings up the image in from 15 secnds to
half a minute and is a 3 minute average developer at 68- 75 degrees. The
strange effect of Amidol is that the longer the print is imersed, the
clearer the highlights. Fog is prevented by less light or the adjustment of
citric acid to POT bromide balance in the Amidol with SOD sulfite.
Both the light bulb and that 36 inch distance along with the 3 minute
emersion in Amidol developer are consistant, constants. Any adjustments can
be made with the time of esposure or an intermediate water bath while
developing. It is important to begin with the light constant described and
the emersion time for the first prints. Make a step tablet and derrive from
there.
Let me know. It's sooooo gratifying to make contact prints.
Steve Shapiro
sgshiya@redshift.com
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