Astrophotography with a Revelation Dob - weights?

I have the clubs 12" Dob made by Revelation. Now that I have the Canon 350D to play around with, I am considering getting a T-adapter to connect it to any scopes eyepiece. But with the Revelation series, have any of you tried it? If so, how did you attached any kind of counterweights at the bottom end of the tube? Tension is a bit of a problem on these scopes to stop them from simply giving into gravity if pointed too low towards the horizon, so I guess it will just fall with the weight of the camera unless pointed straight towards the zenith anyway.

Any ideas?

Seanie.

Although small children and animals are easy to use for counterweights for this job, her indoors complains a bit when I do this. :twisted:

I'm in the same boat and was thinking of purchasing some cradle rings to make the Dob into a Newt?

My 10" Dob is somewhat front heavy with a DSLR attached but in practice the tensioner will hold it. That's not the problem though - it's what you do next! My 10" f4.8 has a focal length of 1200mm and applying the rule of thumb that a 50mm lens is good for 10secs without tracking, the longest exposure you'll get without trailing being visible would be 0.4 secs neglecting any vibraton effects. This means you'll be confined to photographing the Moon, the bright planets and some bright stars. No DSOs or anything.

My solution was to buy a set of rings to get it up on my LXD75 mount - that way I have a photographic solution as well as a quick viewing solution.

There are such things as platforms for Dobs that will make them track for short periods though they tend to be made for one latitude only.

John,
interetsing solution, but I currently come up short (save for the cat).

Paul,
I don't know about whether the tensioners will do it for the coupling of scope+DSLR. I know the Canon body is quite light. I'll probably get a T-adapter and barrel anyway and give it a go. I am reluctant to add straps etc as it is not my scope.

Any more suggestions are welcome.

Hey guys,
when you're talking about using the 12" as the lens for the 350D, and it being necessary for such short exposures to prevent trailing (and thus limiting what you can pick up), would it work to use the rapid fire selection whilst in manual mode, having set the settings, then taking all those exposures and using software to allign them? Even at that, can something like Registax allign such a moving sequence of stills?

Seanie.

yes, but sometimes the periphery of the image can become distorted if there is alot of movement, not usually a problem with planets, but with widefield images of the moon it can be a problem.