12-30-2016, 03:19 PM
Well, in any camera with exchangeable lenses the view finder is shimmed one way or another. With fixed focusing screens it generally is the focusing screen, with exchangeable focusing screens it normally is the frame into which the focusing screens are inserted.
What also is shimmed is the lens mount, to make sure it is exactly at the right distance and parallel to the sensor. Besides this, obviously mirror assembky and sub-assembly for AF etc. are adjusted as well.
Lenses are shimmed as well, as in, the lens mounts are.
Even with all this adjustment, it still is almost impossible to get it 100% right, but mostly it falls within tolerances, after all the shimming done, apart from focusing by means of AF - as lenses need to move relatively loosely, it sometimes requires individual adjustment per camerabody.
In short, all focusing screens are shimmed, whether that is doen directly or indirectly, or at least are shimmable, as indeed occasionally no shims are needed.
Do also note that shims are not necessarily equally thick on all sides. They come in a lost of varieties tfor exact positioning on all sides.
Kind regards, Wim
What also is shimmed is the lens mount, to make sure it is exactly at the right distance and parallel to the sensor. Besides this, obviously mirror assembky and sub-assembly for AF etc. are adjusted as well.
Lenses are shimmed as well, as in, the lens mounts are.
Even with all this adjustment, it still is almost impossible to get it 100% right, but mostly it falls within tolerances, after all the shimming done, apart from focusing by means of AF - as lenses need to move relatively loosely, it sometimes requires individual adjustment per camerabody.
In short, all focusing screens are shimmed, whether that is doen directly or indirectly, or at least are shimmable, as indeed occasionally no shims are needed.
Do also note that shims are not necessarily equally thick on all sides. They come in a lost of varieties tfor exact positioning on all sides.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....