I would like to photograph an object of around 30mm (1.25") in diameter on a 5x4" monorail so that it is around 80mm in diameter.

I have two lenses, a 90mm and a 210mm, and around 40 to 50cm of bellows draw.

My initial question is, will I be able to achieve this magnification with the equipment I have.

Also, I have a "semi-silvered mirror" that sits in a format frame on the monorail (I picked it up cheaply a while ago). I believe it makes it easier to light macro work, but I'm not sure how to use it. If I put it on the monorail, it increases the minimum subject to lens distance quite considerably, and I'm not sure at what angle to position it, and also how to light it.

Any help would be much appreciated.

-- David Nash (nashcom@btinternet.com), September 14, 1999

Answers

lens to film distance = lens focal length (magnification + 1)

Your magnification is about two and a third (8/3). Plug the numbers in and see if your bellows draw handles it. I think you'll make it with the 90 (you should need about 33 cm of bellows draw with this) but not with the 210 (you'll need 77 cm extension). Hope this helps.

DJ

-- N Dhananjay (ndhanu@umich.edu), September 14, 1999.