RE: Carbon on glass with back exposure
Thanks Marek. Since making carbon tissue is quite burdensome (when compared to the simple task of coating paper with a brush and then letting it dry for a couple of minutes), I wanted to know if there's a special knack... Thanks for the tips about clouds and sun's path! For exposure (+ digital negative calibration), I plan to use our local "UV Index" value. (Accessed through internet, given in a pretty precise manner like 9.8... Data is pseudo-actual since readings are made every 5 minutes.) The index is linear, therefore I will just define and convert the times using the UV index as a factor... The station that takes the UV radiation readings is about 14 miles away of my current location, so I hope there will be not much variation between there and here. (Such as; clouds over there, clear here and v.v.) I know about carbon and did some test prints before... (Thanks to Sandy's book + the workshop we took from him few years ago in Istanbul.) Regards, Loris. 3 Temmuz 2008, Perşembe, 9:22 pm tarihinde, Marek Matusz yazmış: > > Loris, > Carbon prints were made routinely at the turn of century with sun > exposure. We are not inventing anything new here. To keep exposure > variations to minimum try to make prints at the same time each day. Make > sure there is no cloud in the sun's path during the exposure. That will > ruin the print as the sharp shadows will disappear. Face the print to the > sun and align it perpendicular to the sun's rays to keep shadows as short > as possible. I guess it would be good to just record light intensity with > a lightmeter. Integrator might be OK, I do not have and never used one. > Exposing film test strips (traditional silver film based) is a great way > to learn carbon. It will also allow you to pick negative density that you > like. You already know how to translate this to a digital negative. > Exposure is tied to dichromate concentration and negative density, but 10 > or 20 % variation will have little effect. > Best of all read some good literature on carbon. > > Marek >> Date: Thu, 3 Jul 2008 11:59:45 +0300> From: mail@loris.medici.name> >> Subject: Re: Carbon on glass with back exposure> To: >> alt-photo-process-l@usask.ca> > Thanks Marek!> > A question about >> exposure: how sensitive is the process to exposure> variations? How did >> you calibrate your negatives for the process? How do> you manage to >> decide the correct exposure time? What is your procedure? Do> you use a >> light integrator?> > Regards,> Loris.> > 28 Haziran 2008, Cumartesi, >> 11:31 pm tarihinde, Marek Matusz yazmış:> >> >> > Carbon on Glass (Back >> Exposure).> >> > ...> > Walk outside, remove the top black cover and >> expose. 1-2 minute of direct> > sun is a good start for testing.> > ...>
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