What is this part of an eyepiece?

[Adz]

Hey all,

Quick question, what does the bottom part of an eyepiece that screws away serve a purpose for?

here is a picture

[Bizibilder]

That's the bit that fits into the focusser. It is removeable so that different sizes / adaptors / filters etc etc may be added/swapped. It also allows easier access to the lens fittings within the eyepiece itself during manufacture. The shallow depression around it is there so that locking screws that throw up a burr when tightened don't cause the eyepiece to get jambed in the focusser tube.

[Adz]

That's the bit that fits into the focusser. It is removeable so that different sizes / adaptors / filters etc etc may be added/swapped. It also allows easier access to the lens fittings within the eyepiece itself during manufacture. The shallow depression around it is there so that locking screws that throw up a burr when tightened don't cause the eyepiece to get jambed in the focusser tube.

Thanks for the help, I should have made myself clearer. I wanted to know why it was detachable, now I know Whats the best policy for cleaning an eyepiece?

[Pete Presland]

Thanks for the help, I should have made myself clearer. I wanted to know why it was detachable, now I know Whats the best policy for cleaning an eyepiece?

don't i think is the best answer and definitely do not take one apart

[Bizibilder]

You can clean your eyepieces but only if they REALLY need it! Most dust etc will be out of focus and therefore pretty much invisible anyway! If you must clean then DO NOT wipe with a soft cloth!!!!! Use a "blower" from a photography shop to blow any loose dust off then, if necessary, you can clean with "cotton buds" and a proper optical cleaning fluid. There are several tutorials here and on other sites that give detailed advice on exactly what to do.