RE: Extending gum range and the tone reversal.
So Marek, do you just put the coated paper under UV and not in a contact frame for 5 seconds or do you put it in the contact frame, flash, then put the negative in? chris ----- Original Message Follows ----- From: Marek Matusz <marekmatusz@hotmail.com> To: alt-photo-process-l@usask.ca Subject: RE: Extending gum range and the tone reversal. Date: Tue, 09 Dec 2008 16:11:18 +0000 >Chris, >I did not clear this test strip, I could do it as well. >I have been flashing my gums for 2 to 5 seconds routinely >now depending how dense my negatives happen to be. Even on >the test strip you can see the much more delicate gradation >in the highlights. Almost like printing in palladium. This >really shows in tri-color gum with the cyan layer, which >defines most of the contrast and tonal gradation. I have >just finished a family portrait that I have done flash and >no flash version. What a difference in the skin tones that >additional flash exposure delivers. Will scan and post >later tonight. Eliminating the stain delivers brighter, >more saturated colours as well. Marek > > > >Date: Tue, 9 Dec 2008 08:16:25 -0700From: >zphoto@montana.netSubject: Re: Extending gum range and the >tone reversal.To: alt-photo-process-l@usask.ca > > >Thanks for this Marek. It is always heartening to see >someone else testing things for the heck of it and you are >the test King! Bleaching, pinhole, yupo, solarization... > >I love how Picasa has that magnifying glass option so we >can really get close in to the test strips. Almost like >being in your dimroom. > >I like also how you can see on your wedges where the >numbers are dull with too little exposure. > >So do you think you will use the flash technique in your >practice in general or only with dense film negs? > >One question: did you clear your step wedges in potassium >metabisulfite or whatnot? It can be hard to determine how >long gum's tonal range is at times because of the fact that >the dichromate gets darker and darker and darker with >exposure and gives a bit of a false read to the step wedge >when, in fact, gum has reached "max black" before the >dichromate has reached "max brown". I don't ever clear >unless I am doing step wedges. I find that gum has a 4-6 >stop range, with 6 stretching it. This is certainly longer >than some books that say it has a 2 stop range, though, and >it looks like from your step wedges you are getting more >like the 4 stops. Do you find this to be the case in >general? I'm including max black and paper white in the >range as steps (wanted to clarify because some don't >include paper white). > >Off to work, though I'd love to have this convo instead... >Chris >__________________ > >Christina Z. >Andersonhttp://christinaZanderson.com/__________________ > >----- Original Message ----- >From: Marek Matusz >To: alt-photo-process-l@usask.ca >Sent: Monday, December 08, 2008 10:55 PM >Subject: Extending gum range and the tone reversal. >AllA few weeks ago I was printing gum from a negative that >was way too dense. It was not my nagative, so I really >could not do anything with it. When I printed a thalo blue >layer I noticed a tone reversal and a heavy stain in the >highlights. I typically do not encounter either as my gum >negatives are not that dense. This was an opportunity to >learn so I printed some step tablet tests and determined >that indeed a little exposure was needed or else a "tone >reversal" or heavy stain resulted in the test prints. That >prompted me to add some 'flash' exposure, no negative in my >UV box. I am posting a test printed with thalo green, one >of the most staining pigments. I had a test strip with >thalo blue and indanthrone blue, but can't find them now. >On the test strip there are 1, 1:30 and 2 min exposures. >You can easily see the tone reversal on the 1 min exposure >where the number 21 is much lighter then say 8. I also >posted RGB readings to illustrate the stain. I wish I had >done a 4 minute exposure as well, next time > I suppose.The center 3 strips are 1:30 second exposure >with 2, 5 and 10 second post flash with no negative. Steps >1-7 are visible on the print, maybe not quite on the scan. >There is also very little stain and no tone reversal. this >is a remarkable density range for gum. This was all printed >and developed on one piece of paper to have the development >constant. I have been printing with a flash for a while >now. This really opens up the highlights, but requires >somewhat denser negatives than typical gum.For those ready >to experiment I would suggest using step tablet and not >existing negatives to test this idea.Always something new >and exciting with gum.Marekjust one picture >http://picasaweb.google.com/marekmatusz1/ExtendedGumRange?authkey=AKZxcCQlqts#5277658299253953138 > >Send e-mail anywhere. No map, no compass. Get your HotmailŪ >account now. >___________________________________________________________ >______ Send e-mail anywhere. No map, no compass. >http://windowslive.com/Explore/hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_anywhere_122008 > 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 |