Mounting Camera on top of Telescope thoughts

[scaramanga]

Hi folks ,

I have a C8 Celestron sitting on a CG-5 Equatorial mount I am thinking that I would like to try and mount my Canon 40d with my fairly substancial Canon L 300mm F2.8 prime lens on top of it for guiding, is this possible ,if so how do I do it?

Or am I wasting my time , I had hoped the fast F number of this lens would work well?

Cheers

Harvey

[ollypenrice]

If I were you I would do it the other way round. Guide with the SCT and image with the lens. The fast f ratio of the lens will indeed work well and the short FL will require a fraction of the guiding accuracy. When you are up and running you might try imaging at long FL but I think you will see why I suggest the reverse order approach!!

Olly

[scaramanga]

Hi Olly,

sorry mate unless Ive misunderstood you I think that is what I was asking , I meant that I wanted to guide with the SCT still attached to the EQ mount and some how mount the camera to the top of the SCT but I am not sure how I would mount it.

cheers

Harvey

[ollypenrice]

Hi Harvey,

Ah yes, good idea. First tip, don't buy one of these;

Tiltable Piggyback Mount 12"

They are truly awful!

Baader make an upside down Vixen rail which bolts to the top of the OTA using the little black Allen key screws intended for accessory mounting. To this you attach one of their clamps, essentially like a saddle plate. Put the camera on that.

http://www.baader-planetarium.de/sektion/s03/s03.htm

Alternatively you could use the accessory screws on the OTA to hold a home made device of some kind.

Olly

[Merlin66]

You could set up an ADM minirail system.

It has a camera attachment for the 1/4" screw in the camera and you could give the front of the lens more support by fitting a guide ring up front.

[scouse123]

I have a 7d which i piggy back using a JOBO Gorilla GRIP, Zip tied onto my Nexstar 8i on CG5 Goto.

Seems ok.