Which mount?

swannies1983 (Dan) · #1 13-06-2006, 04:55 PM

Hi there. I'm in the process of getting a secondhand TAL 200K OTA and am debating on what would be the best mount to get. A majority of people have said the absolute minimum would be a HEQ5 mount but this would depend on what I want to use it for and what additional items I will be connecting to the scope. I'm primarily interested in planetary viewing and astrophotography and perhaps some brights DSOs and therefore, tracking will not be that long. I will be using a Toucam for imaging. As cost is a limiting factor I would prefer not to have to buy a EQ6 assuming the HEQ5 can hold the scope. Alternatively, the original owner of the TAL 200K had his set up on a LXD75 mount. Just wanting to get your opinion on the best mount for such a scope. Cheers

avandonk · #2 13-06-2006, 05:25 PM

I have a HEQ5 and a Tal 200K and the mount is quite adequate. The weight is not the problem it is the motors and gears that let you down with a focal length of 2000mm. For short exposures (60s) unguided is OK. The backlash in the gears (and gearbox on the motors) have noticeble slack. If you load the mount so it never has to go very often from + to - on either axis you should be OK. I have taken many pictures using autoguiding for up to eight minutes and this is OK at FL of 600mm. The Tal200K loses about half of the images due to 'jumps'. I do not know whether the HEQ6 is better.

If you need any more info just ask.

Bert

swannies1983 (Dan) · #3 13-06-2006, 09:20 PM

Hi Bert. Thanks for your input. I don't quite get what you mean about the motor and gears letting you down due to the FL of 2000mm. You also mentioned that you had no problems with long exposures at a FL of 600mm. Did you use a focal reducer with the TAL 200K? I have read up that sometimes it is difficult achieving focus with a focus reducer due to the short travel distance of the rack and pinion focuser. People have made some modifications so that they can infact use a focal reducer. Cheers