CG-5 and C11 - ok for short exposures?

What are the chances that a C11 mounted on a new CG-5 mount will be able to take unguided 56 second images without trailing? I know that this is quite a load for the mount. But I will be using anti-vibe pads and will be careful to balance well. Nothing piggybacked on the scope. I will have a 9x50 finder mounted and I’m using a Mallincam video camera. I would be happy to get un-trailed images maybe 75% of the time with such a setup. Any chance of getting that performance? I can only integrate up to 56 sec with this camera so I don’t need to go longer. If I want to expose longer in the future I will upgrade to a beefier mount for sure. Just curious as to what I could expect with the CG-5. Thanks.

John

John, indeed, that is quite a load for a CG-5. I doubt you would be able to get past 30secs without trailing. You could use focal reducers/correctors to bring down the magnification, maybe allowing you to extend a bit the exposure, but IMHO 30secs would be your limit, if your mount can handle it... but in all reality the C11 is way too bulky/heavy for it.

John Miele said:

What are the chances that a C11 mounted on a new CG-5 mount will be able to take unguided 56 second images without trailing? I know that this is quite a load for the mount. But I will be using anti-vibe pads and will be careful to balance well. Nothing piggybacked on the scope. I will have a 9x50 finder mounted and I’m using a Mallincam video camera. I would be happy to get un-trailed images maybe 75% of the time with such a setup. Any chance of getting that performance? I can only integrate up to 56 sec with this camera so I don’t need to go longer. If I want to expose longer in the future I will upgrade to a beefier mount for sure. Just curious as to what I could expect with the CG-5. Thanks.

John

"Slim to none." I have been able to do decent 30 second unguided images (not all frames perfect) with this mount and a C8. OTOH, I can autoguide it for as long as needed, and have done 20-minute guided exposures with the C8 at f/4 regularly with good results.

The C11 will make things tougher because of its longer focal length and because it will be even more prone to shaking if the wind comes up--that has spoiled more than one imaging session with this mount for me despite the fact I was using a Stellacam II and a C8, which meant shorter exposures and less focal length. You'll also be dealing with a small chip, which will make things even harder vis-a-vis trailing.

Bottom line? Very good as a low cost imaging platform with a C8...C11? Not so much. If you want better, and really want most frames perfect, the place to start would be the Atlas (EQ6) mount and work your way up from there. You'll also want to get your focal length _down_ with a 3.3 reducer.