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SolsticePhoto
12-Mar-2011, 08:12
I'll caveat my question with "newbie here"

I am trying to figure out what lens will let me take a 1/2 to full frame shot of a flower (say a 3" rose) on a 4x5 camera. Using the standard lens equation I find that I am going to need an extremely long bellows for this. Are there a class of macro lenses that somehow cheat this need ? The kind of parameters I am looking for are a 3"(75mm) rose at ~1000mm subject distance. My maximum bellows extension (w/o any gymnastics) is 340mm. By my calculation to get this to work with a 210mm lens I think I'll need upwards 700mm of extension.

If someone could point me in the right direction that would be wonderful

aduncanson
12-Mar-2011, 11:00
You have described making images at magnifications from about 0.6x to 1.2x. There are no macro lenses that cheat the lens equation. A telephoto design does that (in a way) by pushing the rear nodal point out in front the lens board, but only by about half the focal length, not nearly as much as you require.

If you have the budget for one, Rodenstock, Schneider and Nikon all make (made in the case of Nikon) special macro LF lenses in the 120mm focal length that will perform beautifully, assuming you want a sharp image. For far less money, you will probably find that a 150mm/9 Schneider G-Claron process lens will work just as well, but be less easy to focus than the f/5.6 macro lenses. These lenses will not give you the 1000mm subject distance you described, but rather 275 to 400mm (for the 150, proportionally shorter for the 120mm lenses.)

You might find that the 1000mm subject distance is not as critical to your vision as you imagine. Even at only 275mm subject distance, the near and far parts of a 75mm flower are magnified pretty uniformly. If you really do require the 1000mm subject distance then you might look for a 480mm process lens like an Artar, Apo-Ronar or Nikon, and rig a couple of inexpensive monorail cameras together to give you the 1 meter of bellows that you will need.

Good Luck!

Paul Fitzgerald
12-Mar-2011, 11:25
For your 3" flower to be 3" on the film is 1 - 1 OR 4X focal length from target to GG.

For your 340mm bellows a 180mm lens would just work, longer would not get the magnification and shorter would move closer to the target. You could look for a 250 - 300mm telephoto lens, longer would not focus down to 1 meter with your bellows.

Have fun with it.