Epson TVglass + ;+ P-Distaagon 75mm f 3,5

Today I found two Epson heavy and fat zooms intended for projection, one "ELPM05" and one unmarked. optically longer one with the same mechanical dimensions and the same back focus; not yet measured, but estimated by the usual method.

Their image circles are intended to tolerate some perspective control movement. They do illuminate 24x36, but it remains to be seen how flat , sharp and evenly illuminated it is (probably a very small chip provides the input, so a very small sharp picture should be expected (my optics text book claims that TV lenses are optimized for high contrast at low resolutions aand not for the higher frequencies I assume that also applies to lecture-hall projectors))

Any info ad the origin and construction of these (assembled in China) is welcome.

The third piece of glass i got today was a P-Distagon for a Hasselblad-projector. This obviously has no problems with 24x36 or flatness of field but has a longer back focus than any of my helix candidates. Strangte that it woul need a retrofocal contruction, but Zeiss usually knows what they intend to achieve.

Obviously quite some time before I manage to fit these strange beasts securely to the camera mounts. thin metal, Araldite or mere gaffattape does not seem to be the solution.

p.