Bill beat me to it. They are not assembled in a clean room. And FWIW Skywatcher USA is one heck of a top flight vendor! I have always been impressed by them and am a big fan of their products because of how they stand behind them and work to make it right if it is something they did wrong. The other vendor that really impresses me when it comes to customer support is Explore Scientific.
Particles between lenses of a new SW Esprit 120 Triplet
Posted 17 February 2020 - 06:08 AM
FWIW, I highly doubt that much of any of the consumer-level scopes are assembled in an actual "clean room" due to the expense. Maybe for military specs or very demanding commercial specs, but for consumer equipment? I think doubtful. Anyway, at the bottom of this link are the various standards ratings for clean rooms - https://www.cleanair...tions-class.php
Even if the telescope is not assembled in a clean room particles of that size ,cannot be accepted. The tube surface should undergo cleaning before Assy. Assembly must be done carefully, and quality controlled.
Posted 18 February 2020 - 09:31 PM
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Posted 18 February 2020 - 11:16 PM
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Posted 19 February 2020 - 09:22 AM
Some big over reactions here from people replying. Normally these are on the exterior surfaces, the lens cell is certainly assembled in a clean room but I would bet that the scope is not.
Agree that this was a total over-reaction. There are ways to clean the dust off of the rear of a lens without taking the telescope apart.
I doubt that the lens is assembled in a clean room. If anything, it may be assembled on a laminar flow work bench, but its not a clean room akin to the type that you would see in a laboratory environment.
Edited by peleuba, 19 February 2020 - 09:24 AM.
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