Viewing the Moon

[Miles]

Evening all,

So, I am very much a beginner (at the moment I can recognise Orion... a lot to learn). Anyway, it's a lovely full moon this evening, so like an excited but naive beginner, I went outside and pointed my scope straight at it. It was so exciting, however I couldn't look for long as it hurt my eye. I really should have known better.

Anyway, in the future, what is the safe way to view the Moon? Should I be using a filter of some sort? Unfortunately, it made star hopping rather uncomfortable for the evening. Oh well, live and learn...

[Ally8446]

Hi Miles

What type of telescope do you have ? This will entente us to give you the best advice. 

Regards 

Al

[John]

You can't actually damage your eye but a full moon is bright and can dazzle you for a while. A filter helps to tone down the brightness. Also using higher magnification reduceds the brightness of the surface and makes it easier to observe.

I have been observing the moon myself this evening with my 12 inch dobsonian but at high power (300x plus) and I've not needed a filter.

But if you feel you want to use one, by all means to. They are not too expensive after all.

 

[Miles]

Hi,

So I have a Skywatcher 130p. I was viewing the surface with a 10mm eyepiece on a 2x Barlow.

[Miles]

1 minute ago, John said:

You can't actually damage your eye but a full moon is bright and can dazzle you for a while. A filter helps to tone down the brightness. Also using higher magnification reduceds the brightness of the surface and makes it easier to observe.

I have been observing the moon myself this evening with my 12 inch dobsonian but at high power (300x plus) and I've not needed a filter.

But if you feel you want to use one, by all means to. They are not too expensive after all.

 

Ok, that's a relief (that I won't have damaged my eye). I think I may get a filter (I'll google around),

[Ruud]

When you view the Moon through a telescope, the biggest risk you run is that you lose your dark adaptation. The Moon is as bright as a stretch of asphalt on a sunny day. Watching it with any telescope won't hurt you.

If the Moon's brightness bothers you, three things will reduce  it: 1) use a higher magnification, 2)  use a Moon filter or 3) use sunglasses. A filter is the least convenient because you screw it on the end of the eyepiece.

I use method 1.

 

 

[Paz]

Filters will help but as has been said you can view the moon without them. If you give your eye time to adjust to the brightness slowly you should find it ok. I was checking out the fill moon this evening after looking at darker things and it took probably half a minute of squinting until I had adjusted and then it was ok.

[cletrac1922]

Miles

Use a ND69 lunar filter

You will find will reduce the glare, and also bring out the features on the moon

We have a super moon tomorrow night, peaking at  around 7pm where I am

Night before last was trying to view Comet Iwamoto, just after sunset, located adjacent to the twins in Gemini, and moon was close as well, blocking out what attempting to view

John

[John]

A night with a 99% illuminated moon high in the sky (ie: like tonight) is not a great night for observing deep sky objects. Double stars and the planets (when positioned conveniently) still show well though.

I did manage to get quite a nice view of the Eskimo Nebula in Gemini this evening despite the moonlight so not all DSO's are out of bounds when the moon is bright. Galaxies in particular though take a real hit from the moonlight so it's best to wait for a moonless evening to observe those.

 

[Miles]

Thank you for the advice everybody! At present I am a little clueless, however I'm reading "The Practical Astronomer" at the moment. Also, I notice that the Open University have some introductory materials online.

[MarkBass]

34 minutes ago, Miles said:

Thank you for the advice everybody! At present I am a little clueless, however I'm reading "The Practical Astronomer" at the moment. Also, I notice that the Open University have some introductory materials online.

Yes under their Open Learn courses they have several free ones in astronomy.  You get a certificate of completion at the end of each one. I particularly liked the one on the moons of our solar system. 

[Miles]

27 minutes ago, MarkBass said:

Yes under their Open Learn courses they have several free ones in astronomy.  You get a certificate of completion at the end of each one. I particularly liked the one on the moons of our solar system. 

I have downloaded a Yale lecture series also, though this is for later on. Not wanting to run before I can walk.

[djpaul]

Just come in from a great nights lunar observing . 

Yes I find when the moon is this full it does tend to blur my eyesight for a few seconds after leaving the eyepiece. I have a filter which I do use sometimes. 

[Stu]

A variable polarising filter can be useful, particularly if using a refractor or SCT/Mak. You put one part on the diagonal and the other on the barrel of the eyepiece, then turning the eyepiece allows you to adjust the brightness. Very handy!

[Aldebaran5]

Watched the moon last night with a lunar filter attached, it just takes that bite off the glare when viewing.

Keith

[Astro Imp]

We all have different ideas on the subject of lunar viewing, it's best to find what suits you. There is no right or wrong answer, just your own preference. 
When the moon is about you will find it best to make it the last object of your observing session, that way it won't matter you have lost any dark adaption you may have. 
Good luck and enjoy.

[RT65CB-SWL]

23 hours ago, Stu said:

A variable polarising filter can be useful, particularly if using a refractor or SCT/Mak. You put one part on the diagonal and the other on the barrel of the eyepiece, then turning the eyepiece allows you to adjust the brightness. Very handy!

I use this type ---> ...of variable polarising filter. One of the filters screws on to the 1.25" star diagonal nosepiece and the other filter attached to the supplied eyepiece holder. I do not use the supplied eyepiece holder with my 'top-heavy' eyepieces, (i.e. TeleVue 13mm Nagler/type 1, TeleVue 6mm Radian, Meade 8.8mm/series 4000 UWA... images below).

[Alan64]

Hello Miles, and welcome to our hallowed pastime. 

I second the choice of a variable-polariser, as it will also help to dim down Venus to see its Moon-like phases, and for Jupiter to see more detail.  The polariser will also reduce and even eliminate those pesky spider-vane flares...

That was my experience when using my 150mm f/5 Newtonian.  You have just the next size down, a 130mm f/5, and quite a light-gatherer in its own right.

You can get two of these and screw them together, then rotate to adjust the level of dimness or brightness...

https://www.365astronomy.com/Polarisation-filter-with-30-transmission-level-1.25-inch-M28-5X0.6.html

It's the same filter, if I'm not mistaken, as this one...

https://agenaastro.com/gso-1-25-polarizing-filter.html

Note within that listing that one gets a discount if they purchase two of them, and for a variable-polariser.  The Orion unit is the same thing...

https://www.amazon.co.uk/Orion-5560-1-25-Inch-Variable-Polarizing/dp/B0069VY9CO

This is my own, and I've had it for many years.  I wouldn't be without it...

[rwilkey]

16 hours ago, cletrac1922 said:

Use a ND69 lunar filter

John, you mean the ND96 filter, the best one is the ND96 (0.9) also knlown as ND13 as it gives 13% light transmission.  Miles, I have found this one the best all-round filter. 

[Miles]

4 hours ago, Astro Imp said:

We all have different ideas on the subject of lunar viewing, it's best to find what suits you. There is no right or wrong answer, just your own preference. 
When the moon is about you will find it best to make it the last object of your observing session, that way it won't matter you have lost any dark adaption you may have. 
Good luck and enjoy.

Yes, I think this is how I shall do it from now on; Moon last. It's not exactly difficult to locate.

[Miles]

Thanks for the advice everyone. I shall read up on filters as it did really hurt my eye. Also, I'm going to get some different eyepieces for different magnification when I'm a bit more experienced.

[Unklewhale]

I also find a variable polariser set very useful. The idea of splitting into two locations and just twisting the eyepiece is a nice touch I hadn’t thought of. I’m going to give that a try.

 

[reezeh]

Hi Miles and welcome!

If you're anything like me you'll tire of looking at the full moon; not only is it over-bright, but it is flat, dull and samey - the only real draw are the crater rays. Wait till there's shadows; it'll knock your socks off!

[cletrac1922]

When doing astronomy presentation to joeys/cubs, scouting movement, and observing the moon

Lot of the kids say I cannot see it, and when you look at their face, and big white dot high lightening their face, from the moon reflecting through the eyepiece of my 10" dob

When finally adjust their eye to eye piece, lot of WOWS

So rewarding  

[rwilkey]

On 18/02/2019 at 22:31, Ruud said:

A filter is the least convenient because you screw it on the end of the eyepiece.

You do not have to screw the filter to the eyepiece, it can be placed anywhere in the focal chain.  If you have a 2"-1.25" adaptor you can screw the filter on to it and consequently you can use it in combination with 2" or 1.25" eyepieces, this is the method I use and it works very well, the only disadvantage is that 2" filters are more expensive, but more versatile (you get what you pay for!)