Glass filter to eliminate dust

[shyam]

Hi

can i put a glass near the opening end of the telescope  for eliminating dust on to the primary mirror of celestone 114 eq newtonian telescope

[laudropb]

This not really recommended as the glass will almost certainly cause some distortion to your image.

[Cornelius Varley]

24 minutes ago, laudropb said:

This not really recommended as the glass will almost certainly cause some distortion to your image.

What he said. A small amount of dust isn't going to significantly affect the optical performance of the telescope.

[mikeDnight]

It is entirely possible to replace the spider with an optical window, which would have the secondary attached to it. An optical window however would be an expensive item, as it would need to be made of optical crown, polished and figured to be optically flat and would need anti reflection coatings. It would then need a lens cell to hold it in position. So in answer to your question, Yes you could use a glass window to protect the primary and secondary mirror, but it would be costly.

Modern mirrors are well protected by overcoating. Dust can be removed by washing if the dust was excessive, but a dirty lens or mirror is better than a damaged one. I'd be inclined to blow off any dust if possible, and keep the scope capped when not in use.

Mike

[acey]

1 hour ago, shyam said:

Hi

can i put a glass near the opening end of the telescope  for eliminating dust on to the primary mirror of celestone 114 eq newtonian telescope

Sure. If it's anti-reflection coated it'll only cause a small amount of light loss and if it's of high enough quality it won't distort the image unduly. But it'll be expensive and it'll dew up quickly unless you take further measures. And, er, it'll get dusty. So what's the point?

[shyam]

 whats the best solution, India is a land of dust and pollution. 

[JOC]

I guess it might also slow down the cooling time?

[Charic]

.......as above, it could be done, but another option that will require less worry  from you and less cleaning would be to buy a refractor telescope?
That said even a lot of dust  in the open Newtonian won't hurt the mirror for visual use, it only affects your will power to leave well alone, but a proper strip and clean will improve your knowledge of how the telescope works, remembering that you'll have to put it all back  together again then collimate!

[Peter Drew]

 

The best solution for India, or wherever for that matter is not to worry about it until you can't see your face in the mirror. Good practice to keep the telescope capped when not in use.