200PDS vs 250PDS vs Quattro f/4

[SAW]

Hi,

I want something with a long'ish focal length for galaxy imaging. I'll be using a 183MM and it will be mounted on GEM45 I'm not sure which of the above scopes to go for ? My current imaging set up, Stellamira 90mm with 2600MM, filter wheel etc etc weighs 8kg and the mount is fine with it. Is the 250PDS and Quattro going to be too much for the Gem45 ?

Thanks.

[Clarkey]

I don't have a GEM45, but it suggests in the blurb a limit of 20 Kg. For imaging you probably do not want to go more than 2/3 of this which puts it in the same range as an HEQ5. I think the 250 may be pushing it. Not just weight, but any breeze is likely to cause problems unless you are in a very sheltered spot. Which Quattro? I assume the 10", which although smaller than the 250PDS is still big. Have you considered an RC8?

[SAW]

I think the 200PDS will be the safest choice.

[wimvb]

As @Clarkey wrote, it's not so much the weight. It's the size. A larger telescope will catch more wind, which will affect a mount's tracking. Unless you can have the telescope in a dome, you're probably better off with the 200PDS. With cmos cameras that have "small" pixels, you'll be hard pushed to see the difference in image quality between a 200PDS and a large telescope with a 400 mm mirror. Unless you have that telescope on a dry and cold mountain top. But if you want a managable scope with long fl, you should probably check out RC scopes.

Edited June 18, 2023 by wimvb

[Jerry Barnes]

My GEM45 seems quite happy with my 200PDS for what its worth.