Telescope for moon photography on a budget?

[AstroRoad]

Hi All,

I've done a fair bit of untracked landscape astro photography over the past few years (12mm - 50mm focal lengths), and during the last few months my interest in taking close up high quality moon photography suitable for large print has really started to develop. I shoot on a Sony A7S and A7R , so no standard telephoto lens is going to give me the reach I want. I used stellarium to simulate focal length and I think around 1500mm is where I want to be at the wide end.

Because I have very limited funds my thoughts were to by a used telescope now that is compact and lightweight enough to mount on my existing tripod which has a head load capacity of about 6kg (tripod is about 15kg from memory). Once my hobby funds recover in a year or so I could then look to get a heavy tripod / equatorial mount I can grow into a bit for extended and accurate tracking. I aware this hobby could develop into something more, so want to get as much ongoing value as I can from my purchasing decisions.

Optical quality of the scope is my biggest consideration as I want to be able to produce large prints. As such I *think* most refractor scopes in my price range ($500aud at most) are not suitable as I understand it I should be looking at an ED Doublet or APO scope for CA minimisation as well as needing a high quality Barlow lens (for magnification) and matched field flattener (lens curvature correction). That route seemed to quickly escalate out of my price range.

I'm currently have an eye on getting myself a used Skywatcher 102/1300 mak which will put me in the focal range ball park I'm looking for and is also very compact and lightweight (about 2kg I think). Not a particularly fast scope, however optically the images taken with this scope of the moon I've seen look very decent. Unless I get lucky with a used scope that includes a good quality Barlow, I was thinking I could look at getting a good quality 2.5x or 3x Barlow down the track a bit for getting those really close up shots I'm looking for.

Would really appreciate any feedback or advice on my direction for my intended use case. It's all a lot to take in and some of the $$ involved are a bit mind boggling to someone with pretty limited funds and high expectations 🤪.

[barkingsteve]

Hi AstroRoad and welcome.

First off you do not need a 'fast' scope for imaging the moon, it is very different from astrophotography. You take a video at high speed and stack the best percentage to produce a high quality image, look up lucky imaging. Tracking is not so important, as long as you can track well enough to take around 2+k of high speed frames ( 60+ fps ) the higher the better. The idea behind this is to image the clearest frames between the atmospheric disturbances and stack the best ones using ( free ) software such as autostakkert or registax.

If you want close up images then the higher the F ratio the better, you also need to consider pixel size of your camera to get the best scale, it is never as easy as point and click  have you considered a 6" rc for the moon ?  weight is just under 6kg with an F ratio of 9 ( 1370 fl ) if you are not afraid to learn how to collimate ( if needed ) then this would make a great moon scope ( imo ) 

https://www.firstlightoptics.com/ioptron-telescopes/ioptron-photron-6-ritchey-chretien-telescope.html

I would also suggest having a look around the Moon imaging sub forum and check out what other people use.

https://stargazerslounge.com/forum/35-imaging-lunar/

Hope some of this info helps and good luck in your adventure into moon imaging.

[johninderby]

Unfortunately the 6” RC is slightly over your budget. 

https://www.bintel.com.au/product/bintel-gso-rc6-f9-astrograph-metal-tube/?v=322b26af01d5

[CraigT82]

Yeah a little mak is probably going to be best for what you want to do. Either the 102mm or a 127mm if you think the ball head can handle it. Great little scopes in a small package and perfect for lunar  snapping. 

Just a point to note. Lunar photography is best done with the moon high in the sky, to minimise atmospheric effects, so you may end up spending lots of time with the scope pointing up high which will be a pain with a ball head especially with a dslr hanging off the back of the scope.  You may want to consider something like a used skywatcher AZ4 mount, or even a used eq3-2 in your budget. Will make things a lot easier and the eq3-2 will track (with some motors added).

As mentioned above the really close in stuff is done by 'lucky imaging', where you used a snall format video camera to shoot fast frames (50 to 150fps) which the enables to you catch the brief moments of good seeing. Software then isolates these sharpest frames and stacks them to improve the SNR and allow sharpening. Not sure what the sony A7 does video wise but worth investigating. 

[AstroRoad]

Thanks everyone for the replies, I'll certainly have a look at lucky imaging. I had read some bits and pieces about stacking frames, though I wasn't entirely sure how much this applied to lunar. I guess I'm about to find out, though the vintage of my Sony cameras isn't going to do me a great deal of favors in terms of video capability. I actually have a little Panasonic GX85 that can do 4k 24p, other than that it is FHD at 60FPS or the Sony cameras at FullHD 30fps. Something more to get my head around, guess I'll be off to the lunar forums to get myself up to speed on the post processing side of things.

 

Thanks again.