Neutal Density, Polarising or Moon filter ?

gaa_ian (Ian) · #1 17-09-2005, 08:34 PM

Ok ...I have seen all of the above recommended for lunar viewing.
I have a typical giveaway "Moon" filter as supplied by Andrews with their scopes.
Which is which & what is the difference/ Is one better than the other

ballaratdragons (Ken) · #2 17-09-2005, 08:41 PM

Yes they are different Ian. Polarising filters are adjustable, ND filters block stray and excess light and a Moon Filter is usually just darkened glass to cut glare.

See here:http://sciastro.net/portia/advice/filters.htm

gaa_ian (Ian) · #3 17-09-2005, 08:56 PM

Thanks Ken
The polarising filer might be best as it suits differnt phases of the moon.
I am interested to find the best as I did an astronomy night for a School camp the other night and the moon through my 10" Dob left everyone feeling a bit stunned by the brightness, but I'm not keen on the green cast given by the traditional "Moon Filter"
It gives a false impression of what the moon looks like in reality.

ballaratdragons (Ken) · #4 17-09-2005, 09:15 PM

And the Moon filter isn't much good on any other object either! It's just TOO dark.

h0ughy (David) · #5 17-09-2005, 09:40 PM

get an orion variable polarising filter! you can adjust it to suit no matter what your looking at

ballaratdragons (Ken) · #6 17-09-2005, 09:44 PM

Sounds good Houghy! but what is it like for DSO's LOL!!

h0ughy (David) · #7 17-09-2005, 09:52 PM

Quote:

Originally Posted by ballaratdragons

Sounds good Houghy! but what is it like for DSO's LOL!!

I don't know ken,
the serious answer
maybe if the light is travelling in one particular linear plane you might be able to tease out some detail. But I would say that it would dim it for sure.

Now I am finished with the serious answer, I would have it in the eyepiece and get a DSO in the eyepiece, then just before I ask you to look, turn it 90 degrees to give you the best view

ballaratdragons (Ken) · #8 17-09-2005, 09:56 PM

Haha!

I have seen the multiple filter attachments advertised. You would have to be doing a serious night of viewing/photography to use one (or want a scope that is full of gadgets).

ballaratdragons (Ken) · #9 17-09-2005, 10:00 PM

A warning for anyone using filters (especially Moon filters).

Remember to take it out of your EP when you have finished using it.

Don't make my mistake of leaving it in! Makes it very hard to see other objects with a Moon filter left in

and I do it quite often

h0ughy (David) · #10 17-09-2005, 10:01 PM

Quote:

Originally Posted by ballaratdragons

Haha!

I have seen the multiple filter attachments advertised. You would have to be doing a serious night of viewing/photography to use one (or want a scope that is full of gadgets).

there might be a few guys on this site that could vouch for that! i have a CPF for my 18-125 sigma lens, and one for the 50-500, and at QLD astrofest i bought an orion VP for 2" eyepieces. it is excellent

square_peg114GT · #11 18-09-2005, 02:21 AM

Quote:

Originally Posted by h0ughy

get an orion variable polarising filter! you can adjust it to suit no matter what your looking at

I'll 2nd that. The Orion VP also makes a great Mars filter for scopes 8" and larger.

johnno · #12 18-09-2005, 02:49 AM

Quote:

Originally Posted by ballaratdragons

A warning for anyone using filters (especially Moon filters).

Remember to take it out of your EP when you have finished using it.

Don't make my mistake of leaving it in! Makes it very hard to see other objects with a Moon filter left in

and I do it quite often

You,Me, and I bet quite a few others Ken.
Regards.John

ausastronomer (John Bambury) · #13 18-09-2005, 10:19 AM

I have a 2" orion Variable Polariser and it works well. Remember however, that any filter that reduces the amount of light reaching your eye also reduces the amount of fine detail reaching your eye.

CS-John B

Miaplacidus (Brian) · #14 18-09-2005, 10:25 AM

I've been trying to track down a local supplier for the 1.25" and 2" Orion Variable Polarisers. Where did you guys get yours?

Cheers,

Brian.

ausastronomer (John Bambury) · #15 18-09-2005, 11:04 AM

Quote:

Originally Posted by Miaplacidus

I've been trying to track down a local supplier for the 1.25" and 2" Orion Variable Polarisers. Where did you guys get yours?

Cheers,

Brian.

Brian,

Bintel carry the 1.25" version in stock and do a special order on the 2". It took them about a week to get the 2" version in for me.

CS-John B

Starkler (Geoff) · #16 18-09-2005, 11:35 AM

Quote:

Originally Posted by ausastronomer

Remember however, that any filter that reduces the amount of light reaching your eye also reduces the amount of fine detail reaching your eye.

Yes and for this reason I dont use any kind of filter for viewing the moon.
I own an Antares brand variable polarising type and just dont use it.
Sure when you first look you get a bit of eye-shock, but the eye adjusts quickly enough.

square_peg114GT · #17 18-09-2005, 02:21 PM

Quote:

Originally Posted by Starkler

Sure when you first look you get a bit of eye-shock, but the eye adjusts quickly enough.

That can't be good for your eyes! Your eye was never meant to to view the moon thru a 10" pupil! Owwww!

Dave47tuc (David) · #18 18-09-2005, 03:01 PM

I have a Variable Polariser filter and a No 96-0.6 filter
(really just a blockout filter )

I use neither, cuts out to much light for me IMO.

I find using the 80A blue filter and 15 Yellow helps bring out fine detail for my eyes.

IMO I think the Variable Polariser is a waste of money.

h0ughy (David) · #19 18-09-2005, 03:40 PM

Quote:

Originally Posted by Dave47tuc

IMO I think the Variable Polariser is a waste of money.

thank goodness that's only your opinion

i find that it decreased surface brightness,

but increases contrast and you get to choose by how much.

best thing since sliced bread

Dave47tuc (David) · #20 18-09-2005, 03:52 PM

Quote:

Originally Posted by h0ughy

thank goodness that's only your opinion

i find that it decreased surface brightness,

but increases contrast and you get to choose by how much.

best thing since sliced bread

As I said IMO.

One mans sliced bread is another mans toast.