Primary mirror

[griff44]

Just bought my scope and already i have bits on the mirror - can anyone advise how to remove them??

[Chris H]

What are the bits? If they are specks of dust or even slightly larger bits then they won't affect your viewing so I'd leave well alone for the time being.

[NGC 1502]

The bits wont affect the image, but they can be very annoying, especially

on a new scope.

You could remove the cell and use a bulb blower, this may remove loose bits,

but go carefully, it's easy to do damage.

Best to remove the cell as suggested, or live with it I think.

HTH, Ed.

[griff44]

I think they're loose, well must be as only just bought the scope - i was thinking of using a long feather duster but gently brushing the mirror??

[Chris H]

DO NOT TOUCH THE MIRROR

If you are determined to remove them then you have to drop the primary mirror out of the bottom of the tube by removing the screws which hold it in place. As NGC1502 said you could blow the 'bits' of with a hurricane blower, like this http://www.scopesnskies.com/images/astroboot/Image-14_2010-05-30.JPG, or if they are really stuck you can wash the mirror using purified water. But I really would not worry too much about bits on the mirror. Have you seen these bits by looking at the mirror whilst shinning a torch light on it? If so you should see the state of my mirror when doing the same it looks filthy but it works perfectly fine.

[yeti monster]

I've had a primary out 3 times today. Resetting is a doddle and so long as you use some (not so) common sense whilst handling them, there is nothing to fear except fear itself.

A lens brush/hurricane blower shifts anything that wants to be shifted and a lens pen will move any accidental fingerprints. But, unless there is a better reason for removal of a primary than just a few dust particles, better to leave well alone.

[NGC 1502]

I fully agree with Chris, a filthy looking mirror still works ok !!

When I first joined my local astronomy club in 2002, I was shocked at the state

of some members mirrors --- looked like the bottom of a garbage bin !!

I don't like it that bad, but it's best to relax about it, as best you can.

Cheers, Ed.

[griff44]

Thanks for the sound advice, they look to be loose bits so I'm sure the air blaster will take care of them if I need to - if it's not going to affect the view then I might leave alone

[Astro_Baby]

It wont affect the view and if you take the primary out you'll need to recollimate and believe me as a beginner you wont want to get your head into that right now - best to leave it alone. Get some eyetime in firts with the scope while you get your bearings as it were - time to collimate later when you need to.

[griff44]

I've checked the collimation already, "a bit of a [removed word]" i know what you mean but the scope is bang on - as one would expect from a new scope. Even did the star defocus check and was perfect!