Oh dear: another "alternative" lens that demands a not-inconsiderable amount of creativity in order to produce a usable image. This is a 50/2.3 Baltar from Bausch & Lomb; I'm honestly not sure whether it's an f2.3 or a T2.3 (f2). I am sure, however, that it's a fixed-focus lens in some odd-size thread mount, and that its diaphragm has been removed, relegating it to wide-open-only applications. As I said: oh dear. But on the other hand... The Baltar is one of the truly legendary cine lenses. My copy of the Vade Mecum describes the 50mm Baltar as a 6-element, 4-group configuration, and calls the Baltar a "prestige series." A point of interest: a sibling series, the Super-Baltar, was used in the filming of Gone with the Wind. A "prestige" lens indeed! The lens was used here on an embarrassingly homemade-looking "adapter" involving an M39-to-M42 step-up ring and a lavish amount of blue painter's tape, with the contraption mounted on a helicoid focusing tube fitted to my M42-to-m4/3 helicoid adapter. I'm no fan of duct-tape engineering, but I'm also reluctant to make irreversible lens modifications unless absolutely necessary. The results, I think, are excellent by any objective standard, but out-and-out stunning when one takes into account the limitations inherent in this cobbled-together setup. Wide-open sharpness is exceptionally good, color is vibrant and accurate, and the images have (to my eye) great "plasticity." A significant investment of time and effort, to be sure; but one amply repaid, I think, by the outcome.