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Moon filter


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Hello

my first question (takes deep breath) I’m looking at buying a moon filter I have a nexstar 6se, now it’s possible I’ve had an information overload but I’m sure I read or watched a video that said SCT type scopes  dim the light of the image  because of the design  

with that said the standard density of a moon filter I’m looking at (Baader Neutral Density Moon filters) is 0.9. Because of image being dim (if that’s correct)would I be better off getting a filter with 0.6 density to avoid the image being too dim.

i know the filter is there to help your eyesight etc ive had the scope for a couple of days and haven’t actually used it during the night yet so I have no idea how bright the moon would be.

Any advice would be much appreciated even to tell me I’m barking up the wrong tree 

Andy

 

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I have a 6SE and in my experience the Moon is not too bright in this telescope. No filter needed.

You could try looking through sunglasses. If that improves the image, you might want a filter. (For me, the image just got dimmer, not better.)

SCTs, btw, have a secondary through which no light can enter, but apart from that, the optics of the 6SE are quite bright. 

 

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Sunglasses work, as does reducing the aperture ?
The Moon being so bright, on my scope, I often leave the  telescopes dust cap in place but remove the smaller 2" aperture cap!
This reduces the glare somewhat, great for the Moon.
I discovered today that I have a Moon & Skyglow filter, but cant remember the last time I used it, because of the two methods I use.

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The moon is not going to be too dim but I do recommend a variable polarizing filter... with it you can adjust your brightness and i find that it allows be to pick out a fair amount more of detail due to the much increased contrast... even the full moon looks detailed through it.

 

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1 hour ago, Demonperformer said:

I bought a moon filter when I first got my 6SE (later upgraded to an 8SE) and I think it came out of its box precisely once ... to try it and decide I didn't need it.

Cannot comment on the SE line, but I have an 8" Dob and had a similar experience to this. Used the Moon filter one time and then decided I did not need it. The moon is extremely bright (even to the point of being a little shocking), but I just don't want to use the filter. 

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I would not say it is correct that SCTs produce a dimmer image than other scopes. They have a long focal length so operate at higher power for each given eyepiece than faster scopes, but at the same magnification (and exit pupil) the image should be very similar.

Alot depends upon the sensitivity of your eyes. We are all different and people will say they observe the moon with no filter with no problem and they are correct. However I'm sure there are others who would find it too bright and would benefit from a filter. A variable polarising filter can be quite handy, particularly if you put one part on the barrel of the diagonal, and the other on the eyepiece then you can simply turn the eyepiece to adjust brightness.

Masking the scope down to a smaller aperture does work too, but also cuts the resolution down so you won't see as much detail. Not ideal.

I normally use a Baader Neodymium filter which does a great job of knocking back the brightness just enough, and also works very well on Mars and Jupiter to cut the glare and improve contrast.

Maybe just have a try first and see how you go. Upping the magnification is a great way of spreading the brightness out and making it more acceptable if you struggle with it, providing you don't go too high of course.

Welcome to the forum by the way :)

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Thank you all for the great responses. Much appreciated , being new to astronomy there certainly are many factors to take into account, much food for thought  

I’m  hoping for a break in the clouds tonight so I can try the scope on the moon. 

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First welcome to SGL.
As you have just found when asking a question we all have our ideas, it is rare to get complete agreement.
I'm with @Demonperformer, bought a moon filter when I started and used it once/twice, It's stayed unloved and unused in my eyepiece case since.
Use your scope and make your own decision.
Good luck and enjoy your time under the night sky.

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