Filter required for the moon?

Discuss practical questions about using equipment,
finding celestial objects etc.
Posts: 40
Joined: 05 Dec 2006, 12:44

Filter required for the moon?

Postby NightHawk » 07 Dec 2006, 00:29

I'm thinking of purchasing a telescope in the near future.

I was told by somebody a while ago, that you need a filter for looking at the moon since it is so bright. It has been on my mind for a while now.

Is this true?

Any explanations or advice appreciated. Thanks :D

Posts: 285
Joined: 15 Nov 2006, 22:17

Moon filter

Postby pbholmes » 07 Dec 2006, 18:56

I know you can get them, e.g. from
but I've never used one myself.

With my compact and bijou 114mm Newtonian, I've looked at the moon a few times without finding it painfully bright.

I've never looked at the moon through a bigger scope, so maybe you need one for those.

Solar B
Posts: 162
Joined: 07 Dec 2006, 23:00

Postby Solar B » 07 Dec 2006, 23:20

unless you are using a very large aperature telescope ie 250mm on a near full moon you should not need a polarising filter to cut the glare.
brian :D

Posts: 40
Joined: 05 Dec 2006, 12:44

Postby NightHawk » 08 Dec 2006, 00:13

Thank you for your replies.

I don't know much about sizes.

The person that told me about the filter worked with the 10" and 16" at my university. Thanks for clearing things up! (250 millimeters = 9.84251969 inch)

You are saying that 250mm is large. They have a 37"! I never saw that one though. Must be enormous!

Solar B
Posts: 162
Joined: 07 Dec 2006, 23:00

Postby Solar B » 09 Dec 2006, 00:39

Even if you were thinking of purchasing a large app telescope a polarizing filter for your eye piece would only cost about £11 and you could have
mine at any time. brian :)

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Joined: 11 Dec 2006, 15:32

Postby bhenderson50 » 15 Dec 2006, 18:53

I have been observing the moon through my 12" scope, and although it appears bright at first, the eye pupil soon contracts to compensate. I don't think a moon filter is necessary - just don't try observing any faint objects any time soon afterwards! You will not be able to see too much for a few minutes after.

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