using enlarger for contact printinggreenspun.com : LUSENET : Large format photography : One Thread
I recently moved up from 35mm to lf with an 8x10 field camera and 5x7 reducing back. I contact print both formats on a C700 condenser enlarger with 35mm neg carrier in place, sandwiching neg and enlarging paper between plate glass and foam pad. So far, results aren't bad, but a major problem is the short exposure time, e.g. 6 seconds for polycontrast III RC with the head at maximum height and my 50/4 enlarging lens stopped all the way down to f/16, making dodging and burning difficult, if not impossible. I don't want to detach the base because I still need the enlarger for 35mm. Because I like the controls the enlarger makes possible, I'm not ready for a light bulb either. Slower papers, Azo and POP's, to judge form previous postings, aren't going to allow the same range of choices as do enlarging papers. For money reasons, a bigger enlarger is out of the question. So I'm trying to make do with my little Omega. Is there such a thing as a ND filter for the filter drawer? I'm thinking about a lens with a smaller minimum aperture, say f/32, but this idea has got me wondering about the effects, if any, of printing with the lens stopped all the way down. I could use some help here. And while I'm at it, a couple of related questions. Do the much discussed limitations of condenser (vs. diffusion) enlargers (esp. increased contrast and Callier effect) apply when contact printing on an enlarger? Also, Ansel says (Print, pp. 68-69) to set the lens focus *forward* from the position that produces sharp edges of the negative carrier, so that the "image" of the enlarger's diffusing screen, or dust on the condenser, will not be projected on the paper ... esp. when the lens is stopped down. Which direction is forward? In any case, here stopping down does seem to bear on image quality. Thanks in advance for any help with these issues.
-- Nick Jones (email@example.com), December 28, 2000
Extend the lens cone downwards, you might need to remove the film carrier too. Then try putting some diffusion material (like tracing paper) below the lens. You can add layers to get more density.
-- Ellis Vener (firstname.lastname@example.org), December 28, 2000.
You could choose a cokin ND filter or some other brand to add density in order to increase the exposure time.
But you might want to find some gel sample packages that can do the job.
I guess that I should explain what I mean by gel samples. Although the brand name escapes me at present there are companies that make gels for filtering lights - most often for movies. They sample these gels in little packs, kind of like paint swatches. One company makes these swatches in about 2 1/2" squares and there must be close to a hundred different types including colour correction and neutral density ones, in a pack.
Now you may not want to use these non optically corrected filters on your camera - although I did some colour copying, needed the blue filter to compensate for the incandescent lights, and got excellent results. In any event the way that you are planning on using the filters then optical excellence is moot, and you won't get them any cheaper.
-- David Grandy (email@example.com), December 28, 2000.
You can adjust the focus to spread light over a larger area (move towards the negative carrier). This will reduce the intensity somewhat.
You could make a large ND filter to fit your largest negative carrier by exposing your 5x7 film to a completely smooth surface (make the image out of focus in the camera to make it completely smooth). You could use 35mm to make a small ND filter this way. Best to use a film with a clear or neutral tint base. The steps for your film speed test would probably suffice.
I am astounded at your printing time. Does a 35mm negative blown up to 8x10 print as fast with this paper? Maybe you just need a slower paper?
The Callier does not apply to contact printing in this fashion.
-- Charlie Strack (firstname.lastname@example.org), December 28, 2000.
I'm also pretty surprised by your exposure times. Presuming you've got the correct bulb in the enlarger, and you're not developing in straight Dektol, maybe your negatives are thin. Ask someone experienced and known to be a good printer if you can compare negs sometime.
Try Azo--you might like it. I do. Multicontrast filters are handy, but you can adjust the contrast in other ways.
-- David Goldfarb (email@example.com), December 28, 2000.
Optical sharpness from the lens is not an issue here, only the evenness of the illumination. Opal glass, tracing paper and anything else that is translucent but not uneven in texture will work as a diffusing/light attenuating material. You must have a hell of a bright light source to get such short printing times though, maybe a change of bulb is in order as well. Regards, ;^D)
-- Doremus Scudder (ScudderLandreth@compuserve.com), December 29, 2000.
This sounds very strange. I sometimes contact print 8x10 negatives using my enlarger, which has an Aristo 4500 VCL head which I set at a contrast of 2.0 (on a scale of 5.1, 5.1 being the brightest). I set the head at 13" and remove the lens and negative carrier. With all of that, I still get exposure times with enlarging paper in the 15- 45 second range and when I switch to Azo I get times so slow (60 - 90 seconds) that I switch to a light bulb for Azo. Maybe you just have a very bright light source, or maybe as someone else suggested your negatives are on the thin side. FWIW, stopping the enlarger lens all the way down will have no adverse effect when contact printing because you're not really using the lens for anything. I doubt that the Callier effect is relevant when contact printing either but since I use a cold light I don't know much about it.
-- Brian Ellis (firstname.lastname@example.org), December 29, 2000.
Thanks to all for your replies and good suggestions. I went with a Kodak Wratten neutral density gelatin 0.90 three-stop filter. The 75mm x 75 mm size just fits the filter drawer on my enlarger. The eight times longer exposure now gives more latitude for error and ability to dodge and burn.
-- Nick Jones (email@example.com), January 14, 2001.