Re: solarplate images up on my website
Notice the difference though. Chris' measles are dark in the light areas, while Susan's are white in the dark areas.
My .02 cents/sense is the causes are related, but are manifested for different reasons. I've suffered through both of them. Both have to do with uneven contact during exposure, as you may have guessed.
Susan, however, unlike Chris, is using a vacuum frame. Contact should be flawless, right? Wrong. Why, has to do with the "tackiness" between OHP and the KM73 plate which was documented in my procedure. Took me about a year to figure this problem out, but my excuse is I had to go between Boulder and Denver once a week to actually print the tests, like Chris. But, I'm not as bright as her either.
Susan: If you want to test this, take a virgin KM73 plate with the mylar removed, and a virgin piece of OHP (without an image printed on it), sandwich them under the vacuum frame and hit the switch on the vacuum. I'll bet you see a similar, but subtle pattern of patches manifesting like leprosy within the first minute of drawdown. The aquatint screen, unlike your image transparency, is made of real film and doesn't have this issue, but the OHP is tackier against the KM73 plate and this is the problem. The remedy for me has been baby powder, very lightly dusted over plate with a hake brush (Jan gave me the idea several years ago). If you were using baby powder, the other key is to not let the image exposure draw down too exceedingly long. I basically wait until the Krene goes flat against the bed, then hit the exposure switch with no extra drawdown time beyond that. Since the screen exposure is not the issue, you can draw down on it as long as you want. I do things in this order:
Expose Screen to plate
Dust plate with baby powder
Expose Image to plate (minimal drawdown time)
Hope that helps.
I've got some other things I'm testing out to help with the OHP issue with the KM73 plates and will report back if I come up with anything better than the above.
Christine and all... I also posted some gravures tonight at http://sssusans-studio.blogspot.com/ Christine... mine also have a case of what I call the midtone measels. I just came in from the studio, and I'm so sleepy I can't keep my eyes open. I will take a better look at your many (!!!!) wonderful experiments in the morning. Thank you for making them available. yawnnnn... Susan www.dalyvoss.com On 2/19/07, email@example.com <firstname.lastname@example.org> wrote:Dear all, Camden was kind enough to put up my solarplate images today on my website seeing as I am "website challenged". Here is the URL: http://czaphotography.com/show.php?what=learning&which=4 If this doesn't work, then it is at: CZAphotography.com>Learning>Solarplate. I have added text to the images to show you some problems, issues, etc. I have had with the stuff. They are not perfect images by FAR and I consider myself a neophyte solarplatist. But at least you can see what it looks like for those who don't know what solarplate is. A couple of the images are "combotypes"--solarplate/cyanotype and solarplate/woodblock oh and solarplate/watercolor. A bunch of the images are printed using a bitmap black ink only neg (Epson 2200) 600 dpi in and out--very low tech (the orchid, the Boy Doesn't Meet Girl, the Kissing Chickens--had to add a little humor in there). Hopefully this will continue the dialogue. I just ordered KM73 plates today. I wish I could say I just ordered a vacuum frame today, too :) Chris Assistant Professor of Photography Photography Option Coordinator Montana State University College of Arts and Architecture Department of Media and Theatre Arts, Room 220 P.O. Box 173350 Bozeman, MT 59717-3350 Tel (406) 994 6219 CZAphotography.com