Lunar 'scope set-up suggestions?

[Jamie Carter]

I'm a keen moon observer (and new here), primarily using 15x50 Canon image-stabilized binoculars, but also an old 4-inch 'scope that recently broke. 

 

I want to take things to the next level and invest in a 'scope powerful enough to study lunar features as the terminator creeps, including craters, mountain ranges, and perhaps even the lunar X, etc. It would be great to have the option of photography in future if that doesn't hugely change what I should buy, but observing is by far my primary goal here. Any suggestions please? Budget is £1.5k+. 

 

Thanks! 

Jamie

 

[vlaiv]

Hi and welcome to SGL.

I find your post very interesting simply because you have budget is allowing for so many options. It's usually the other way around - people have limited budget and want to be able to do all sorts of things.

You on the other hand want to observe the Moon and have more than adequate budget for it

I think it would be best if you consider other aspects like portability, ease of use and setup, size and weight, do you want tracking mount.

Aperture is key for high power observing, but sometimes can hurt - in poor seeing smaller scope will be less affected and provide you sharper more pleasing image. With larger scope you will be able to counter this by using aperture mask to obtain - small clear aperture (no central obstruction) less affected by seeing and slow F/ratio - helps with focusing and easy on eyepieces.

My personal choices would be:

8" or 10" dob being F/6 or slower (small secondary optimized for planets/moon) with some sort of tracking - either goto dob mount or eq platform - with selection of barlows and eyepieces.

Or slower ED refractor on tracking mount. Here you will run into budget issues soon if you go for larger aperture, you will be limited to about 5" max and mount will take a way part of budget.

Other good options to consider would be 180mm Maksutov, or 8"-9.25" SCT - both requiring EQ type mount and with potential issues with Dew and cool down - but are considered good planetary scopes.

As for lunar photography - if scope can be used visually and has tracking - you will just need to add planetary camera and suitable barlow or telecentric lens. You will need a laptop or computer that you can use "in the field" - camera + barlow can be as little as £250 or £400-£500 for "state of the art" (a bit more if you add accessories like filters/filter wheels and want to automate everything but it's not needed for great lunar shots)

[Mark at Beaufort]

Hello Jamie and welcome to SGL.

I believe that a quality APO or ED Refractor would best meet your needs. This 4" Refractor will give brilliant views of the Moon - https://www.firstlightoptics.com/pro-series/skywatcher-evostar-100ed-ds-pro-outfit.html - and if you decide to go into astro photography, in the future, this will still be an ideal scope.

The next question is a suitable mount. For general visual observing an Alt/Az mount is the easiest to use but it has limitations as regards Astro Photography. For imaging you really need an Equatorial mount. This mount has both Alt/Az and Eq but  your budget is being stretch to its limit - https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-az-eq5-gt-geq-alt-az-mount.html

Although the Scope 9mentioned above) has an eyepiece, for visual observing, you will need some more which adds to your expenses.

One of the best views I have had of the Moon was using a 4" APO Frac and binoviewers which gives a wonderful 3D effect.

Hopefully, you will get further advice - but you may wish to attend this astro event on the 9th March - https://practicalastroshow.com/ where you will be able to talk with vendors and see the scopes to get an idea of size and weight.

[Davey-T]

Hi Jamie and welcome to SGL.

I have a 10"SCT that is ideal for observing and imaging the Moon but the price is a bit of a jump from 8" to 10".

An alt/az mount is a lot more convenient for observing and imaging the Moon and avoids annoying meridian flips just as you get settled.

Something like this is in budget and leaves enough for a planetary camera.

https://www.firstlightoptics.com/se-series/celestron-nexstar-8se.html

Dave

[jetstream]

1 hour ago, Jamie Carter said:

I'm a keen moon observer (and new here), primarily using 15x50 Canon image-stabilized binoculars, but also an old 4-inch 'scope that recently broke. 

 

I want to take things to the next level and invest in a 'scope powerful enough to study lunar features as the terminator creeps, including craters, mountain ranges, and perhaps even the lunar X, etc. It would be great to have the option of photography in future if that doesn't hugely change what I should buy, but observing is by far my primary goal here. Any suggestions please? Budget is £1.5k+. 

 

Thanks! 

Jamie

 

I imaging is seriously in the cards down the road a C8 SCT or bigger can meet your needs. If imaging is not a consideration, and if seeing is good a large, low obstruction dob ticks boxes IMHO. A 12" f5.3 OOUK? btw the views  of the moon through my 15" dob with nice mirrors gives stunning views with piles of fine detail.

Aperture determines the amount of fine detail theoretically visible and the the optical quality of the scope,seeing and thermals determine how much of it you will see.

[Davey-T]

Ideal scope here.

Dave

 

 

 

[John]

Hello and welcome to the forum !

For the budget you have, the choices will be overwhelming as Mark suggests above.

My suggestion would be to take your time, visit the show if you can and see what others are using who seem to share your interests.

Personally I would not let a possible interest in imaging somewhere in the future dominate a definite interest in lunar observing now - some of the equipment is complimentary to both pursuits, but some not.

[Jamie Carter]

Wow, thanks so much to all, your advice is much appreciated. 

I need to rule out a big Dob (I would love one, but lack the space). 

I'm also not likely to use laptops/webcams etc. outside BUT I do have a Canon 6D I currently use for wide-field Milky Way etc. It would be great if I could use that occasionally to get a half-decent image of the Moon. 

Luckily, I am in no rush so will examine in detail all of your excellent advice, get to the  https://practicalastroshow.com, and likely bother you all with more questions!  

[Alan64]

You can't beat a fine refractor, and for the sharpest and most contrasty images....

https://www.altairastro.com/Starwave-102ED-FPL53-Refractor.html

That one comes with a no-nonsense, tried-and-true rack-and-pinion focusser.  It is also an FPL-53 doublet, which would acclimate to the outdoor conditions almost immediately, and ready to ramp up the power.  A Maksutov takes about an hour.  Maksutovs have been described as "refractor like" in the quality of the images, and the only reflective design so described.  In any event, a Maksutov is almost there in that regard, quite close at times, but not quite to the same level in the end.

This one is of a practically identical configuration, but with an FPL-51 doublet instead... https://www.teleskop-express.de/shop/product_info.php/info/p4964_TS-Optics-ED-102mm-f-7-Refractor-Telescope-with-2-5--R-P-focuser.html

Then there is this 110mm f/7, with a 10mm increase in aperture... https://www.altairastro.com/Starwave-110ED-Refractor-Telescope-RP-Geared-Focuser.html

In "refractorland", every single, extra millimeter counts.

As for a mount, you could go with a manual alt-azimuth for visual... https://www.firstlightoptics.com/alt-azimuth.html

Or, you could get this equatorial now with a single-motor drive for the RA-axis, for automatic tracking, and for visual, but also perhaps for a bit of dabbling with a camera...

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eq5-deluxe.html

https://www.firstlightoptics.com/sky-watcher-mount-accessories/single-axis-dc-motor-drive-for-eq5.html  

...and upgrade the mount with a go-to kit in future, when you're ready.

I have a 102mm f/8 fluorite doublet...

...and I like to observe the Moon, too...

[vlaiv]

This might cause a bit of "war", but I have to say it:

Any diffraction limited 8" scope with reasonable central obstruction (less than 35% or there about) will simply be better than premium 4" apo (unobstructed aperture, premium figure - 0.98+ Strehl class) in both contrast and detail for same magnification when conditions are right.

There, I've said it

 

[Davey-T]

16 minutes ago, vlaiv said:

This might cause a bit of "war", but I have to say it:

Any diffraction limited 8" scope with reasonable central obstruction (less than 35% or there about) will simply be better than premium 4" apo (unobstructed aperture, premium figure - 0.98+ Strehl class) in both contrast and detail for same magnification when conditions are right.

There, I've said it

 

Just read Avanis post and having tried no end of scopes he reckons the ideal Lunar scope is a 8" / 9.25" SCT.

Dave

[Scooot]

I think these are pretty much designed for Luna & planets

https://www.orionoptics.co.uk/OMC/omcmaksutovcasse.html

[John]

I'm just looking down the lists of posts to see what scope design has NOT been advocated yet - then I'll suggest one of those !

[Davey-T]

1 minute ago, John said:

I'm just looking down the lists of posts to see what scope design has NOT been advocated yet - then I'll suggest one of those !

Lunt 

Dave

[vlaiv]

3 minutes ago, John said:

I'm just looking down the lists of posts to see what scope design has NOT been advocated yet - then I'll suggest one of those !

I think that classical Cassegrain is definitively overlooked type, and certainly so in this context - would you mind taking that one (at least one with small CO)?

 

[John]

Maksutov-Newtonian ?

Superb and versatile design in my opinion. Very much "apo refractor-like" planetary and lunar performance

 

[vlaiv]

7 minutes ago, John said:

Maksutov-Newtonian ?

Superb and versatile design in my opinion. Very much "apo refractor-like" planetary and lunar performance

 

You just had to pick and "exotic" type there?

On a more serious note, any real advantage Mak-Newtonian would have over MCT for stated purpose (Moon - I know it will have better wide field performance and be better all rounder and even photographic instrument with flat field, but for high power lunar only)?

[John]

Smaller secondary obstruction mainly.

I had an Intes made MN61 (150mm F/5.9) mak-newt and it was a stunning scope at high powers (about the same as an excellent 5 inch apo) but also delivered wide views when needed.

The downside is the length and weight of the MN optical tube compared to a maksutov-cassegrain of course.