thenews24

Hey thats nice, thanks for posting. I was going to ask if you're mono or colour, and where does your Ha filter go? Also, It looks like youre not using the Geoptik as a support, so how is the camera/lens supported? Using the lens support foot?

I do use the Geoptik. Here's a quick video of the adapter to lens, with 1.25" HA filter threaded in. You can use 2" in this adapter if needed.

geoptik_to_lens.wmv

Ah, so that's where the focussing is hiding. (Doh!)

Quite a nifty idea, given the limited back-focus...

I'll have to see if merely "clamping" suffices.

A Bahtinov mask helps. This was shot with the 200mm f/2.8 with that microfucser and bahtinov mask. Even with a HA filter in the train, I can get nice diffraction spikes with enough exp bin combo:

foucisng 200mmf2.8withmask.wmv

I personally love the 200mm f2.8, which I always shoot wide opne. With the help of a microfocuser, I can get sharp, pinpoint stars edge to edge. I am currently using the lens coupled to the Atik 314. Although this is not the ideal combination in temrs of image scale, I can still achieve nice round stars and the FOV is decent. When m tired of using ccd's, I'll throw the lens on the DSLR for some really wide views, and the reults are superb. For under $1,000 USD, this lens is the best option for fast, wide field imaging on a budget, although the geoptik adapter will add to the cost.

Here's my setup. I guide with a 400mm f/5 orion shortube. It is overkill really, but by inmaging at half of the guide FL, i can get up to 20- 30 min subs no problem.

Inspiring!

My first DSO. Of course M42. Using a C8 (with focal reducer), Losmandy GM-8, Cannon 60D (not modded). Unfortunately couldn't manage anything more than 30 seconds, so had to crank up iso. Having problems, not with polar alignment, but with input voltage to the mount. It seems to give out in RA every so often and image drifts west just slightly enough to give me trails. I was told to try using more amps but stay at 12volts. I have been using 12v and 1amp. But going to try 12v 3amps to see of that fixes my problem. Hopefully it is just a power issue. It's a used gm-8, but everything looks good and sounds good.

This was roughly 12 X 30 sec, @ 3200 iso. Think I used 5 darks.