Two near-identical 43cm + 47cm groups together would give a combination much closer to 22.3cm. Cleaning micro-scratches and other damage can cause a severe degradation of performance.įWIW, the combination of a 32cm lens with a 47cm lens ought to give a 19cm lens by my calculation.
However, Meyer were late to the table in applying AR coatings to their lenses and an uncoated version will obviously have lower contrast than a coated example.Īlso, condition is everything with a lens. I imagine the IQ will be similar to that got from the more common Schneider 'convertible' Symmars of 210mm FL. The fact that two of those lenses gave inferior image quality didn't seem to worry them much! If three focal lengths and apertures are given, then the two longer FLs will be those of the front and rear groups separately and the shortest FL that of the combination.Ĭompendium lenses like this were once popular with frugal photographers, who effectively got 3 lenses for the price of one. This is usually to the detriment of the combined image quality at the shorter focal length. With most 'covertible' Plasmats, you remove the front group to get the longer focal-length (and smaller aperture).
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