Neutral Density Filters for Lunar Viewing?

[Mak the Night]

Does anyone use an ND filter for observing the Moon? If so, have you ever compared it with a neodymium filter? I have a Baader Neodymium and a Celestron 0.9 ND filter. Unfortunately the Celestron won't thread into all of my diagonals or even eyepieces (not unusual for Celestron filters of any description).

Baader Neutral Density Filter

I'm just curious in hearing anyone's experiences with ND filters.

[Piero]

I don't use filters on the Moon. Most of the details are there before the first quarter or after the third quarter. At those times the glare is not so high to require a filter. You can always reduce the brightness by increasing the magnification, or decreasing the exit pupil.

[Mak the Night]

31 minutes ago, Piero said:

I don't use filters on the Moon. Most of the details are there before the first quarter or after the third quarter. At those times the glare is not so high to require a filter. You can always reduce the brightness by increasing the magnification, or decreasing the exit pupil.

OK thanks. That sounds about right. I have found a neodymium useful though in twilight conditions. I was wondering if an ND filter may be useful in twilight. I've used a Wratten No. 12 Deep Yellow at twilight and it did seem to darken the background a tad.

[Knighty2112]

Plus on most scope end  caps you can leave the main one on, and just take out the smaller aperture cap to reduce the glare from the moon too when it is past first quarter etc. 

[Mak the Night]

33 minutes ago, Knighty2112 said:

Plus on most scope end  caps you can leave the main one on, and just take out the smaller aperture cap to reduce the glare from the moon too when it is past first quarter etc. 

Doesn't quite work on SCT's & Mak's lol.

[Mak the Night]

I've always wondered why filter threads aren't universal. My Lumicons won't thread into TV eyepieces or a WO diagonal I have. Yet they thread into everything else. Baaders seem to thread into everything. Weird.

[ronin]

I suspect that for the moon a moon filter is more for comfort for the observer and so falls into personel preference. I know that the full moon is not the best time to observe but it sure is the most spectacular time, especially with people around that have not used a scope.

I have never used a moon filter but my scopes fall into the 100mm bracket so light gather is not excessive from such an object. Have observed it full through a 6" SCT and it was bright, left a residual image on the retina for about 30-60 seconds.

If you have the Baader filter then give it a try, all it takes is about 5 minutes, but do it as an experiment only.

[Mak the Night]

6 hours ago, ronin said:

I suspect that for the moon a moon filter is more for comfort for the observer and so falls into personel preference. I know that the full moon is not the best time to observe but it sure is the most spectacular time, especially with people around that have not used a scope.

I have never used a moon filter but my scopes fall into the 100mm bracket so light gather is not excessive from such an object. Have observed it full through a 6" SCT and it was bright, left a residual image on the retina for about 30-60 seconds.

If you have the Baader filter then give it a try, all it takes is about 5 minutes, but do it as an experiment only.

I have slightly light sensitive eyes and often need to wear shades during daylight. I found the Full Moon's brightness tolerable with a 130mm aperture but the only filter I've really used with 102mm & 90mm scopes is the Baader Neodymium. However, I shall soon be acquiring a 235mm SCT and I was curious as to people's individual experiences with ND filters. The most common ND's transmit 13% of the available light but there are weaker and stronger variants. I know filters are very subjective in use, I was interested in any personal accounts of using an ND filter. You're right, of course, I'll have to try it myself lol.

[Knighty2112]

I remember posting a query about filters a while back, and one of the replies I got back from a member was along the lines of you don't need a filter to look at the moon, just wear a pair of sunglasses to look at it through the EP. Not tried it so can't vouch how good or not the images might be! Hehe!  

[Stu]

You could try a variable polarizing filter. One filter on the diagonal and one on the eyepiece then just rotate the eyepiece to get the brightness you need.

There are many different views on the usefulness of filters, all the way from the 'never use them' up to the people who really find benefit from them. I suspect the main differentiating factor is people's vision. With my left (observing) eye, I have no problem, but the view with my right eye is much brighter and more dazzling so I would feel the need to use a filter if my observing eye was like this.

[Mak the Night]

1 hour ago, Knighty2112 said:

I remember posting a query about filters a while back, and one of the replies I got back from a member was along the lines of you don't need a filter to look at the moon, just wear a pair of sunglasses to look at it through the EP. Not tried it so can't vouch how good or not the images might be! Hehe!  

That's so crazy it might just work lol.

[Mak the Night]

53 minutes ago, Stu said:

You could try a variable polarizing filter. One filter on the diagonal and one on the eyepiece then just rotate the eyepiece to get the brightness you need.

There are many different views on the usefulness of filters, all the way from the 'never use them' up to the people who really find benefit from them. I suspect the main differentiating factor is people's vision. With my left (observing) eye, I have no problem, but the view with my right eye is much brighter and more dazzling so I would feel the need to use a filter if my observing eye was like this.

Yeah, I suppose a variable polariser is the logical way to go as it is relatively customisable to the individual and conditions. I know ND filters are used a lot in photography, astronomy or otherwise, but as most ND filters block 87% of the available light I'd have thought they were quite an aggressive filter.

[Louis D]

Get a binoviewer to look at the full moon.  It's a match made in heaven.  The splitter cuts the brightness by slightly over 50% to each eye.  Second, both eyes adapt to the brightness greatly reducing glare and eye strain.  Third, the moon looks almost three dimensional.  It's almost addictive to just pan around the surface and see details normally washed out monoviewing.  Easily one of the most satisfying binoviewing targets out there.

[Mak the Night]

31 minutes ago, Louis D said:

Get a binoviewer to look at the full moon.  It's a match made in heaven.  The splitter cuts the brightness by slightly over 50% to each eye.  Second, both eyes adapt to the brightness greatly reducing glare and eye strain.  Third, the moon looks almost three dimensional.  It's almost addictive to just pan around the surface and see details normally washed out monoviewing.  Easily one of the most satisfying binoviewing targets out there.

Yes, I've done this with my WO bino and Hutech and Baader ortho's and it does look pretty stunning. I normally use a Baader Neodymium filter as well. 50% seems a lot of light loss, it is difficult to tell on a 102mm Mak though.

[Mak the Night]

I may have solved the problem of my Celestron ND filter not threading onto everything.

It fits into this Celestron (Synta) AstroMaster T-Adaptor/Barlow, which in turn, being bereft of an undercut, fits every diagonal I have.

[rwilkey]

I have found that ND (0.9) filters work very well, I prefer fixed density to the variables as you know what you are getting.  Of course, the idea is to reduce the light, this helps identify the craters and mountains more clearly in my view.  The Baader Neodymium filter does a similar job, but I find I prefer to use the ND filters in the long run.  I use the Lumicon ones which I find are the best.

[Mak the Night]

2 minutes ago, rwilkey said:

I have found that ND (0.9) filters work very well, I prefer fixed density to the variables as you know what you are getting.  Of course, the idea is to reduce the light, this helps identify the craters and mountains more clearly in my view.  The Baader Neodymium filter does a similar job, but I find I prefer to use the ND filters in the long run.  I use the Lumicon ones which I find are the best.

OK thanks. I will definitely try my Celestron ND when I get the chance. I guessed there might be similarities with the Baader Neodymium. If I like the ND I may even splash out on a Lumicon.

[Mak the Night]

This Orion 13% ND filter (artwork from their site) below

is remarkably similar to my Celestron ND 0.9 (13%) 'Moon' filter. Orion USA also sell Celestron ND filters. What's the betting that they came from the same Pacific Rim factory? Mine says 'China' on the filter itself so I'm guessing Yunnan Province, very probably Kunming where a great deal of optics are manufactured.

[niallk]

On 03/05/2016 at 22:26, Louis D said:

Get a binoviewer to look at the full moon.  It's a match made in heaven.  The splitter cuts the brightness by slightly over 50% to each eye.  Second, both eyes adapt to the brightness greatly reducing glare and eye strain.  Third, the moon looks almost three dimensional.  It's almost addictive to just pan around the surface and see details normally washed out monoviewing.  Easily one of the most satisfying binoviewing targets out there.

+1

[Dave In Vermont]

I play with 3 filters for the Moon, depending on the phase and what I'm up to: 80A Blue, Baader Neodymium, and a Polarizing 1% - 40% 2-filter set.

These all have many other uses as well. So one can feel justified in buying them for more than just the Moon. As an aside, my polarizing-filters are made in Japan, and came from Orion-USA, and it's great for Venus.

Dave

[Mak the Night]

4 hours ago, Dave In Vermont said:

I play with 3 filters for the Moon, depending on the phase and what I'm up to: 80A Blue, Baader Neodymium, and a Polarizing 1% - 40% 2-filter set.

These all have many other uses as well. So one can feel justified in buying them for more than just the Moon. As an aside, my polarizing-filters are made in Japan, and came from Orion-USA, and it's great for Venus.

Dave

Do you use the 80A for a very bright Full Moon Dave? I believe it only transmits around 30% of the available light. Although that isn't as aggressive as a basic 0.9 ND (13% transmission).

[Dave In Vermont]

Gotta run -

80A Blue may be good on a full Moon. But I tend to avoid the 'searchlight' stage of our neighbor.

Dave

[Mak the Night]

12 minutes ago, Dave In Vermont said:

Gotta run -

80A Blue may be good on a full Moon. But I tend to avoid the 'searchlight' stage of our neighbor.

Dave

OK thanks Dave. I'm going to have to experiment more with my 80A I think.

[Knighty2112]

35 minutes ago, Mak the Night said:

OK thanks Dave. I'm going to have to experiment more with my 80A I think.

80A Blue is also good for Jupiter too. I use it quite often when viewing it when I want to tease out a little more detail on the planet. 

[Mak the Night]

7 minutes ago, Knighty2112 said:

80A Blue is also good for Jupiter too. I use it quite often when viewing it when I want to tease out a little more detail on the planet. 

I actually tried an 80A on Jupiter with my 102mm Mak, but totally forgot to take exit pupil length into account and it wasn't much of a success. I'm getting much more aperture very soon, so I'll try again.