Moon Filter Necessary with 8" Dob?

[Rich_B]

Hi 

Will I need a moon filter for lunar observations with my soon to arrive 8" Dob?

I seem to remember reading somewhere that the brightness may be blinding without one.

Many thanks

Rich

[gnomus]

I find the brightness of the moon blinding through even smaller scopes.  I got a Baader ND (in fact I bought two) and I am happy with it (them).

[John]

I don't find the need to use a moon filter with any of my scopes, including my 12" dobsonian.

You will get differing views from folks on this one - it seems a personal thing !

 

[nightfisher]

If you find it a bit bright just up the magnification, this will dim the surface to your eye

[Gazabone]

2 minutes ago, John said:

I don't find the need to use a moon filter with any of my scopes, including my 12" dobsonian.

You will get differing views from folks on this one - it seems a personal thing !

 

 Could only get away with that with very grubby eps of mirror (or both).  

On a more down to earth (?!?!?!) note, may depend if you want to look at fainter objects after the moon!

[LukeSkywatcher]

I dont use one.

[swamp thing]

28 minutes ago, Rich_B said:

Hi 

Will I need a moon filter for lunar observations with my soon to arrive 8" Dob?

 

Rich

Short answer, no  

Save your money for a more worthwhile accessory  

[Mr Spock]

No need for a moon filter at all

[John]

21 minutes ago, Gazabone said:

 Could only get away with that with very grubby eps of mirror (or both).  

On a more down to earth (?!?!?!) note, may depend if you want to look at fainter objects after the moon!

I use my 12" dob to see deep sky objects down to 14th magnitude, but not on nights when the moon is in the sky !

My optics are always pristine of course

Seriously - a moon filter is really not an essential piece of kit at all IMHO.

[SacRiker]

Depends on your sensitivity. Take a look without one -- you'll soon figure out if you need a filter! I know when I look at the moon even with just binos it is too bright. I need the filter. Luckily my scope came with one packed in.

[SilverAstro]

37 minutes ago, Rich_B said:

Will I need a moon filter

As you can see, ask 10 A.A.'s and you'll get at least 11 answers It all depends on what you mean by "need" ,,

You will not need one to protect your eye from damage, no risk there,,

,, but you may wish to use one for your own comfortable viewing. Experienced viewers like to keep to a minimum any intervening glass between them and the view and this depends upon persuading the eye ( actually the pupil) that you are viewing a daylight scene even though your brain knows it is the middle of the night The bottom line is try it if you have not already ordered one, ie. if your scope is about to arrive without one ! In my experience ( with a 6" Newt ) I could determine no advantage in persuading my eye to do without and to  accept the brighness, so I used a filter. In any case you will probably 'need' one when you show the magnificent sight to your nearest&dearest, for they will almost certainly protest without

 

[Putaendo Patrick]

In the mean time, you can just put a lens from a pair of sunglasses over the eyepiece. This will give you an idea of whether you personally will be more comfortable with a filter.

If you do end up buying a filter, don't buy one with a plastic ring. I my experience these rings wear out and get chewed by the EP thread very quickly.

[cloudsweeper]

I went from a 5 inch to an 8 inch, and the Moon and Jupiter (as examples) can now be quite bright and merit use of a filter.  An Nd has high transmission, whereas a Moon filter has lower transmission, so reduces glare more.  A variable Moon filter would allow you to be more selective of how much reduction you employed.

And as another contributor said, you can always up the mag to reduce the brightness.

Doug.

[Rich_B]

Thanks all for the advice.

I am about to order some BST Starguider EP's (8mm & 25mm) and a Celestron Omni Barlow and wondered if I should add a moon filter to the order.

I'll leave it for now and see how I get on without first.

Rich

[BGazing]

I have 0.6 filter, but I reckon I will also get a 0.9, because when it is over half full I find the brightness blinding. YMMW.

[Wabbit]

OP as you can see, this is easily a question of personal preference. For my 8 inch Dob I prefer a moon filter simply because without one I have to cut short my gazing times. (Far too bright/too much strain on the eyes) For what it's worth I would pick one up and add it to your kit.

[Dave In Vermont]

Yes - your mileage may vary. But if you do want one, I suggest a variable polarizing-filter. These can act as a dimmer-switch for a telescope, and is useful for other things than just the Moon - like double-stars where one is many times brighter than the other, phases of Venus and Mercury, etc. These are sold as a pair and reduce the light coming through from 1% to 40%. Here's an example:

http://www.amazon.com/Orion-5560-1-25-Inch-Variable-Polarizing/dp/B0069VY9CO/191-9976517-8304637?ie=UTF8&*Version*=1&*entries*=0

On the Moon I find them cool for making shadows along the terminator (the imaginary line between the light and shadow) more stark and detailed.

Have fun,

Dave

[spike95609]

I think it really depends on what sort of magnification you'll be using. If you're using about 150-200x then that should dim the moon sufficiently without a filter being needed. If you want to use lower power though, for a steadier and wider view, it can be quite uncomfortable on the eye, and if you're referring to a moon map at the same time it'll take a few seconds before you can even see it nevermind read it!

[Jimtheslim]

I have a 10" dob, I have never felt the need for one

[MarkVIIIMarc]

After looking through the scope at the moon for a bit with my right eye I find my night vision is humorously skewed. Try closing one eye afterwards then the other.

Personally I don't use the filter but I can see where it might be useful.

[big9erfan]

I have an 8" dob, for me it's not NECESSARY, but could be nice to have.  

[gls]

On 03/06/2016 at 17:38, Putaendo Patrick said:

In the mean time, you can just put a lens from a pair of sunglasses over the eyepiece. This will give you an idea of whether you personally will be more comfortable with a filter

I wear my sunglasses because I find it easier than using my moon filter lol.

They're probably not as good as the filter though.

[MattJenko]

Having taken my 10" Dob to outreach, the general consensus is that you don't need one. However, it will absolutely ruin any nightvision and make other objects harder to see and also care needs to be taken when moving around after a minute or two looking at an unfiltered moon with lots of other people and scopes about

[Charic]

Blinding but not damaging, just be careful where you tread on your way back into the house, in-case you trip over?

To reduce the brightness I often leave the dust cap on the end of the telescope? On the face of the dust cap there are two raised 2" caps? only one can be removed, and stowed over the other. This reduces the glare quite a bit, but also reduces some contrast, and aperture, but the Moon still looks stunning, as its so close and bright. The other method is to wear sunglasses, or a Moon filter. I have a Moon filter, it stays in the box for what its worth, preferring to use the dust cap, when viewing at higher magnifications.

[Steve]

On 3 June 2016 at 16:34, Rich_B said:

Will I need a moon filter for lunar observations with my soon to arrive 8" Dob?

I find viewing the Moon without a Moon filter is uncomfortable (perhaps I am more sensitive to glare than some others) and it wrecks my night vision.

But if you are observing only the Moon and don't mind the glare then a Moon filter isn't necessary and, like Charic says, you can improvise with sunglasses. The telescope cap's inner aperture can be used to reduce glare, though it also reduces resolution. 

HTH