Re: lens fabricator required - urgent!

Ron Gibbs writes:

Object-image distance is fixed 300mm, including 50mm glass
beamsplitter. Continuous magnification range 2.5 - 5.5x, aperture
~F/2.0. MTF>0.5 @30 lp/mm up to 15mm off-axis image field with <10%
vignetting. Do you know any camera or enlarger lenses that will do
this?

Canon "L" prime lenses in 50mm f/1.4 or 85mm f/1.4 would be candidates.
They are supposed to out-resolve 70 lp/mm sensor chips, and I think Canon
has MTF charts online. Not sure about how you plan to both focus and
magnify with a fixed distance. You need two degrees of freedom. Zoom
lenses are limited to f2.8. And you haven't specified field sizes.

A 5X magnification is about the end of macro and the start of microscopy,
and I sure don't know of any f/2 microscopes.

If by "vignetting" you mean cos^4 dropoff, digital compensation would be in
my mind.
.