Another trick I've used when the print I'm copying is very
glossy/reflective, is to get an 11x14 piece of black board, cut out a
hole in the center the size of the lens, and slip this on the lens
right before you shoot. That way, any shiny bit of your camera won't
be reflected in the print.
Also, never wear a white shirt while copying highly-reflective art. ;-)
----- Original Message ----- From: "Nick Zentena" <zentena@xxxxxxxxxxxx> To: <pure-silver@xxxxxxxxxxxxx> Sent: Friday, June 24, 2005 9:28 AM Subject: [pure-silver] Re: duplicate info
On Friday 24 June 2005 12:24, Chuck . wrote:
get the image he needs with little distortion. The WA has the advantage of being a closer focusing lens than other lenses of longer focal length...
The problem is he'll have to focus closer with the short lens. No? To get the same size image on the negative the camera will need to be closer with the 55mm.
Or should I go for lunch?-))
Nick
The problem with a wide angle lens is the light fall off away from the center of the image. Also, most wide angle lenses are more sensitive to object distance as far as loss of correction. A normal or somewhat long lens is better.
I also disagree with the idea of using diffuse light. For copying photos one needs cross lighting at about a 20 to 45 degree angle. A polarizing filter on the camera is helpful in suppressing reflections from the surface of the print. The position of the lights will depend on the nature of the surface of the photo to be copied. The best copies will be from glossy surface paper. Suppressing the texture of textured surfaces will requrire some experimentation. If you can obtain sheets of polarizing material large enough to cover the lights they can be used in conjuction with a polarizer on the camera to reduce the effect of texture.
Other choices will depend on what equipment is available. A sheet film camera is desirable but not necessary. Where they can be adapted to the camera enlarging lenses are ideal for copying.
A note on distortion: Most camera and enlarging lenses are rectininear, that means that a flat surface with squares on it will be reproduced exactly regardless of the focal length or distance. The "distortion" seen in photos taken with wide angle lenses (but not fisheyes) is from viewing the picture from the wrong distance. The effect does not appear when copying. Most reasonably modern lenses are designed for a flat field although enlarging lenses and process lenses are probably better than average camera lenses for this. Also, slow lenses are less affected by loss of correction when the object is a different distance than the designe optimum, which is infinity for the usual camera lens.
--- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx
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