250px as an imaging system?

[MattJenko]

I have had the idea of converting my 250px 10" dob into an imaging setup for the galaxy seasons and for when long FL is required for a while now. I bought some tube rings and tried it out on an elderly EQ6 last night. My rationale is that if this looks promising, then I will get my own mount for it, and look to upgrade various aspects of the 250px to get it up to scratch rather than buy a whole new custom scope.

I managed to get focus with my Atik 414 + SX filter wheel which was my main worry, although the focus range is extremely tight and with a manual single speed focuser it was very tricky.

I used an ST80 on the back for guiding, so not ideal, but this was just to see if it all works.

This image is 15 x 5 mins L only of M82. I tried a 10 min shot, but it blew out the core and lots more, which is in complete contrast to my ED80!

I think this has lots of promise and I think it is worth getting some losmandy dovetails, moonlite + motor focuser, OAG, secondary dewheater etc etc.

I guess I just want some confirmation that I am not being silly in doing this and wasting my money and time, as the upgrades are more $$$ than the scope   !! 

[blinky]

I think the only real problem is the size of the scope and the danger of wind affecting the guiding. If your in an obsy or a sheltered position it should be fine. Im sure FLO used to sell the 250 and EQ6 as a package?

[steppenwolf]

I have used my 250PX for deep sky imaging and it makes an excellent ' scope for this purpose especially when used with a coma corrector.

Sent from my iPhone from somewhere dark .....

[MattJenko]

I have used my 250PX for deep sky imaging and it makes an excellent ' scope for this purpose especially when used with a coma corrector.

Sent from my iPhone from somewhere dark .....

Good to know from someone who knows! I'm guess that coma corrector would be the Baader, non-reducing one? I have the Skywatcher one and I fear for my focus distance with it. I only have a tiny chipped CCD though, so think I can get away with it for now.

Blinky raises a very good point - it was calm last night, and I would more than a little afraid if the wind picked up

[steppenwolf]

The 'sail' issue is certainly a consideration and I used mine long before I got an observatory but I guess you choose your nights and avoid windy ones but I don't ever recall this being an issue for my own imaging sessions.

A standard Baader MPCC is all I use and it gives a useful 10mm of extra back focus as a bonus!

Sent from my iPhone from somewhere dark .....

[bish]

I've thought about trying that. This chap did the same thing  http://www.mattastro.com/dso.html

[MattJenko]

Bit of a delay in replying, but thanks all for the encouragement. I have decided to go ahead and stage one, upgrading the focuser is underway with a Moonlite ordered from FLO. This can be used in Dob mode as well, so am hoping this great OTA can become a truly multifunctional instrument for me - Dob for me, AzEQ6 for outreach Alt-Az observing and of course EQ AP. Shame funds are such that it needs to be done in stages

[Pompey Monkey]

Matt,

Where did you get your tube rings? I have a 10" revelation Dob that I'm thinking to put on my pier mounted AZ-EQ6 for some longer FL stuff than my 150P-DS.

I'm going to have to either move the focuser and spider down the tube or get some longer screws for the primary to achieve sufficient back-focus. I will probably go for the former, as the latter will probably increase the risk of mirror flop!

Nice image, BTW!

Paul

[tich]

I love mine managed to do some imaging with it last week in the Brecons, just a shame it doesn't get used more often but that's due to my circumstances at work right now but hope to get that changed in the future. Although my first taste of CCD imaging was a bit of a failure but hopefully I'll get it sorted.
I to use a Baader MPCC with mine like Steve has done using the Canon 1000D & I've had some pretty good results so far with it, only downside weight & it being suseptable to wind but then most Newtonians are anyway.





 

[MattJenko]

The rings I have are these (288mm version) : http://www.firstlightoptics.com/tube-rings/skywatcher-telescope-tube-rings.html

They are decent enough, although I want to get a Losmandy dovetail as the main dovetail and use my current vixen-style one for the top for extra robustness.

Moving the primary up the tube would be my preferred change rather than a spider/focuser move!

[MattJenko]

Certainly looks the part! Like the tent as well!

Have you taken the side dob things off then? I was thinking of just leaving those on.

[tich]

When I got mine it didn't come with the Dob base so I removed them as I couldn't see the point leaving them fitted, but you should be able to use it ok with the Dob parts on it as I know a few who do.

 

[ollypenrice]

Probably because of the slightly intimidating size of the beast not too many folks go down this road but those who do seem to post great results.

Good on yer! Go for it.

Olly