>>3766907if i get the wrong/broken thing.
>>3767257yes:
MTO-11CA__MTO-11 1000 mm f10 Maksutov Tele-Optic
SMC Pentax Reflex 1000mm f11
Tamron Adaptall2 SP 500mm f8 mirror 55BB
Tamron SP 350mm f5.6 reflex
ZM-6A 500mm f6.3 Mirror M42 882482
no:
Sigma 600mm f8 reflex
almost all of the shit ones like Bower are ripoffs of this.
...actually It's not so much the design thats flawed, because the physically large diameter is a good thing, and the sigmas construction/helicoid etc is quite good, but the coatings in them seem to be generally shit, or maybe the final assembly of lenses at the rear inside the mount is lame.. i don't really know. Maybe i'm just biased by mine having aluminium (the reflective/mirror part of the lens) separation and not having a good one since the 80's when mine was new. (its fucked now)
I suspect the sigma dedigns all separate fairly quickly due to the design/applicaiton process.
It looks like this, but it's on the FRONT element (the disk in the front lens), so being able to look 600mm down a lens thats 200mm long takes some practice, PLUS its microscopic. So people dont usually see it. and asking sellers to check is pointless.
