Konica Omega 90mm Lens Coverage

[Curtis Mack]

I am considering the Konica Omega Rapid for Instax conversion. Will the lens cover the format (62mm x 98mm)?

 

[Dan Fromm]

Probably not. I have 58/5.6 and 60/5.6 lenses for Koni Omegas. They cover 2x3, i.e., 100 mm but not much more. And the 90/4.5 is a fast tessar type, will probably cover ~ 110 % of its focal length. If the Instax format really is 62 x 98 -- pardon my ignorance, its out of my territory -- it wants lenses that cover at least 115 mm.

 

[Curtis Mack]

Please forgive my ignorance. Since there are no movements, why would it need the extra coverage?

 

[Dan Fromm]

The diagonal of a 62 x 98 mm rectangle is ~ 115 mm, not 100 mm. That's why you should want a lens that covers 115 mm. If you don't care what's in the corners, you can get away with a lens with less coverage.

The Koni Omega shoots 6x7. The format's diagonal is 90 mm and that's all lenses for it have to cover. That the w/a lenses will cover 2x3 and can sometimes be nice economical w/a lenses for 2x3 Graphics is a pleasant surprise.

 

[Curtis Mack]

Thanks. I forgot about the diagonal.

 

[dynachrome]

It might be easier to adapt that film size to a 4X5 camera with a back you can fabricate. If you can accept the nominal 60mm side of a 6X9 roll film adapter you could lengthen the 90mm side by about 10mm and go from there. This sounds like a job for Hin Man.