Meade ETX 125 as a guide scope?

[White Rabbit]

Whadaya reckon, would a mak be any good for this? I dont see why not, but they I dont know anything about it.

I just bought an 8" newt for my Eq5 and want to start some photography.

I could buy an ED80 but if I can use the 125 as a guide scope I can put the money towards a better camera. Besides if the girlfriend sees yet another scope in the house, I'm for it.

The only thing I can see wrong with this is maybe the weight factor.

Thanks
Sandy

[Alchemy (Clive)]

the f ratio might be a bit of a killer if its too high as it will make finding a guide star harder, not sure what the etx is but the ed80 is about 7.5 i tried an f11 once and gave up, some areas that are full of bright stars are ok but if youre after galaxies often theres not enough around particularly as you have a smaller field of view.

[White Rabbit]

I think it's an F15 so yeah that might be a bit of a problem.

thanks for the reply

[pjphilli (Peter)]

Hi Sandy
I use two scopes, a Meade 80mm f6 and a Mak 150mm f13. I found that the 1950mm focal length of the Mak did not permit stable guiding and guiding stars were hard to find. So I bought a cheap focal reducer and set it at maximum spacing before the Mak runs out of focuser travel. This reduced
the focal length to about 950mm which provides good guiding for my Meade 80mm. Finding guiding stars is also easier. Since this arrangement gives a 2:1 focal length ratio over the Meade it means that a say 1 pixel movement in the guiding camera gives only a half pixel movement in the Meade imaging camera.
Cheers Peter

[g__day (Matthew)]

Possible on a good mount with alot of carrying capacity and excellent (rigid) mounting (e.g. Losmandy side saddle bars) to minimise differential flexure for such a heavy OTA.