Lunar shots with a dob

I recently purchased a Meade LPI with the intention of snapping the moon, I have a 10" dob and wondered if anyone out there has tried something similar. I also have a 4" TAL refractor on an equatorial mount, undriven, which I would like to try with the LPI. Any help?

Considering the Moon is your objective, it may not appear as hard as you might think, to try and capture a couple of shots with an undriven scope. I'll dispense some of my advice here.

For either of your two scopes, make sure your finderscope is bang on with what you see in the eyepiece. You can use the LPI in the eyepiece, swing the scope(s) at the Moon using the finder as your guide, let go, and then when steady, take a couple of frames.

As it is the Moon, you will not need many frames - it is bright enough, and therefore, sharp enough as it is. It's a simple way of using an undriven scope, and with a little practice, you'll easily get the hang of it - particularly as it can be difficult to hand-control a dob (usually, once you have removed your hands, there is still a slight shift in position as it balances its own weight to come to rest - I have the TAS 12 inch Dob, so I know the feeling!).

After that, just practice with the software for different exposure and processing techniques!

Seanie.

I know what you mean about the movement of the dob, sometimes it can be annoying and one light touch sends it off on its own. I own a Revelation 10 and the movements are so smooth, too smooth maybe, that this happens regularly. Therefore, I think I start off with the refractor and see what results come out before I consider using the dob.

Hi Lunaratic,

I have done alot of webcam imaging through my 222mm Dobsonian but I had to build a tracking platform for it to make it possible. (See galeries on Kerryastronomy Club link below)
The practicality of imaging without tracking really depends on the focal length (hence magnification) of the telescope you intend to use.
Inital attempts through the Dobsonian (focal length 1280mm) without tracking on Mars back in 2004 resulted in an out of focus Mars being recorded on only 4 of 5 frames of the video as it sped accross the screen! This caused so much frustration that I gave up and started to build the platform.
To record a usable AVI, first of all you must get the target on the screen. Then set the exposure levels, then the focus, (this alone can take minutes) then take at least a 10 second video. Without tracking of some sort the image will cross my screen in about 10 seconds.
I have used the webcam on the 70mm Skylux without tracking quite sucessfully (see images of Venus transit on www.kerryastromomyclub.com/gallery-solar.htm ). Its focal length is only 700mm and hence you get half the magnification. Registax will do the tracking for you then.
To make things more difficult, any planetry imaging really requires a barlow to increase the magnification and hence the difficulty.
I hope I have not put off giving it a go but do start with the shortest focal length scope you have.

Very much in agreement about the tracking.

Post processing such as sharpening or wavelet processing will degrade the image unless you've stacked many frames. I will seldom use less than 600 frames to produce an image of the moon, this means at least a minutes tracking is necessary (at 10fps), and the moon moves quickly through the field of an unguided scope. You can certainly get images with less tracking but getting the best out of them requires some tracking.