I'm thinking of using a lens of maybe 180 or 210 mm focal length with my 8 x 10 to do macro work, > 1:1. These lenses normally won't cover the 8 x 10 format but it seems to me that if I use them at a longer extension for the close up work they will cover just fine since the image circle should expand to fit. The reason for thinking of this is the expense of a normal 4 x 5 lens vs. that for 8 x 10. Can anyone think of a reason why this is a bad idea? I know I'm asking for some long exposure times but most of the work would be indoors in pretty calm and stable conditions.

-- Dick Watson (watsonrm@erols.com), December 07, 1998

Answers

FWIW... I have used my 210 mm Osaka as a C.U. and E.C.U. lens on 8 X 10 and been happy with the results. It's a tessar design, no great shakes, just a good general purpose lens and for contact prints it's working out fine.

As I recall, there was an article in View Camera Mag about shooting 8 X 10 inexpensively some time in '93 or '94. The author relates using a 210mm also, but I think it was an Ektar or similar lens of better quality for the same general purpose. I know Weston mentions using one for some of his vegetable close-ups in his Daybooks. He even tried a 5 inch lens.

Along similar lines, I have used my 150 Rodenstock enlarging lens reversed as a close-up lens for 4 X 5 and 5 X 7. It was awkward, but I was using slow copy film stock, ASA 80 (+/-) so the hat/lens cap shutter method worked fine.

-- Sean yates (yatescats@yahoo.com), December 07, 1998.

The downside would be that general purpose lenses are not optimised to work in this way. The drop in quality may not matter, of course.

If you need magnifications much larger than 1:1, you could even use, say, a reversed 35mm lens.

-- Alan Gibson (Alan.Gibson@technologist.com), December 08, 1998.

At 1:1, the circle of coverage should be twice the diameter of its circle at infinity, so it should work, I would think. I remember reading somewhere that the Kodak 203mm Ektar held its corrections at 1:1, and they can be found listed in shutterbug all the time. I think it covers 5x7, so 8x10 at 1:1 should be ok, coverage wise.

-- Ron Shaw (shaw9@llnl.gov), December 08, 1998.

The 300M nikkor might be your answer. It works very well at 1:1 and offers the option of using the Nikon close up multi element screw in 52mm filter which really keeps bellows extension at a minimum.

-- Dan Smith (shooter@brigham.net), December 09, 1998.

LF lenses not specifically designed for macro work are best corrected for use with the long conjugate (distance to focus) in front of the lens. At reproduction ratios greater than 1:1, the long conjugate is behind the lens. Such lenses often work better if mounted backwards on the lensboard, so that the long conjugate is on the optimal side of the lens.

-- Sean Donnelly (donnelly@c-com.net), December 12, 1998.

I used to routinely use a 203 Ektar on my 8 x 10 Deardorff for life sized images of objects about the size of an apple. The results were as good as anything else I have seen. I also gained enough coverage to use some camera movements. Go ahead and try some exposures and see what you come up with. It worked for Edward Weston.

-- Tony Brent (ajbrent@mich.com), December 12, 1998.