Vixen first light

[LewisM]

First light for the Vixen VC200L. 12 minutes total of 30 images, with 3 darks and 3 bias. Haven't added flats yet. NO guiding, ISO 1250. Unmodified Canon 5D MkII. 20" exposures. First attempt using H-alpha filter as well - you can JUST see the red fringe. Fitted with f/6.3 reducer.

Slightly out of focus, and a bit of collimating to do, but getting a LOT better. This was taken last night, with the moon high and bright, in town. Haven't edited much - if someone wants to have a go and say what they used and which process :)

[Terry B]

Great start.
The scope holds collimation very well. I haven't recollimated mine for years.
Focus is very easy with a Bahtinov mask. I just added a simple motor focusser to assist. These are cheap and fit perfectly http://www.myastroshop.com.au/products/details.asp?id=MAS-051A
My Bahtinov mask is home made from a piece of 3mm foam board.
All adds up to a great imaging scope.
The vixen focal reducer seems to be quite finnicky about the image plane distance. With no focal reducer the image plane is perfectly flat. When I introduced a focal reducer it seemed to introduce a little curvature resulting in elongated stars at the corners of the image. I experimented a bit with the distance but didn't find the perfect diatance. I currently don't bother with the focal reducer but this is because I cant reach focus with it in place using my SBIG camera with a filter wheel and an AO unit. It's just too long.

[LewisM]

Terry, already got 2 Bahtinov masks - work fine, but need a bigger image - I'll be hooking the laptop up tonight (if the weather stays good) to have a crack.

I fitted the Vixen microfocuser on this - big improvement, but still needs tweaking - I will add a robofocus I think.

Going to try it without the reducer next, but quite happy with the progress with it as-is. Reading Steve's info on the reducer, it seems it needs to be 63cm, whereas with the standard Vixen arrangement just as they prescribe, it is 55mm. I guess I'll have a custom 8cm spacer made (I have enough GSO made-out-of-whack tubes here to have a crack at it via my machinist mate).

Guide setup should be installed next week, and then I should be able to crack so real exposure times, considering how solid this entire setup is on the NEQ6.

The very firt image I took with the Vixen - Alpha Centaurus of course - just awed me - I knew I have a LOT of potential in this girl! Tweak the collimation and clean the mirror a touch, and watch out Hubble :rofl:

[Terry B]

It should hold focus perfectly well. Just aim at a bright star and focus on it first with the mask and camera in place. Then slew to your target.