Dear All
I have just acquired a 127 mm aperture, f 3.6 Focal length 600 mm) lens made by Charles Beseler in the USA, see
http://alag3.mfa.kfki.hu/astro/giantlenses/127mm.htm.
The only info I can find is that it is a triplet (therefore should be an apochromat)
I have found one mention only of using a lens of this character in a refractor (with good results).
Has anyone got any leads (I've spent a good deal of today on Google with little to show)
Regards
R