Flashing a B&W Printgreenspun.com : LUSENET : Large format photography : One Thread
I would like to flash a small portion of a B&W print in the darkroom. The manuals I have all suggest that I run out and get a density screen to achieve this effect. However, my enlarger has a color head (Saunders LPL 4550), and my thought is that (perhaps) there must be a way I can take advantage of the colorhead to achieve the same effect (without buying a screen).
Can someone tell me if it is possible to use a colorhead in this manner? If so, any idea as to what the proper filtration settings would be to flash for 5%, 10%, 25% (I use Ilford Multgrade fiber based papers).
Many Thanks, Robert
-- Robert Ruderman (firstname.lastname@example.org), December 26, 2000
Trial and error. That's it. Calibrate it the same as anything else. It isn't just 10% or 21.653%. Get a small night light and attach it to a timer and you have a light source to flash what ever you need. James
-- lumberjack (email@example.com), December 26, 2000.
Dial in some filtration (I would go with yellow for a VC paper), set your lens to a smaller aperture and, with no negative in the carrier, begin making step exposures on a piece of paper. Develop it completely. Find the exposure that just begins to show some faint density on the paper, then back off a bit from that for your flash exposure. The idea is to get the paper just to the edge of being developable--then, when you put the negative in and make your regular exposure, the tiny extra exposure provided in the highlight areas will be enough to cause them to show detail when developed. You may have to adjust the flash exposure a few times to get it just right. If you only wish to flash a limited area, you will have to work out some means of masking the paper before flashing.
-- Ed Buffaloe (firstname.lastname@example.org), December 27, 2000.
I find that a pre or post flash will be to much if it is more than 15% but this is for my system. An easy way of doing this is to take a burn card (small card with a hole in it used for burning a section), tape a piece of frosted mylar over the whole... your small area flash card! With the negative still in the enlarger, dial in the appropriate time and flash away. Do the testing that Ed mentions though. You will need to test for an aquired taste. Cheers
-- Scott Walton (email@example.com), December 27, 2000.
I made a "flashing" light out of a light switch, a 12V yellow side light for a trailer and a 12VAC transformer. I drilled a hole in the yellow plastic cover for the actinic light and mounted the light on the ceiling. I tested it as per above suggestions. If you're only flashing one area, I put a waste sheet (old throw away print)in the easel under the projected image and draw the area of concern with a marker pen. Cut out that area and align the mask with the unexposed (or even exposed) sheet and expose for your pre-determined time.
-- George Nedleman (firstname.lastname@example.org), December 27, 2000.