Maximum weight on nexstar mount

[tarqs101]

Hi

Does anybody know what the heaviest OTA is that the nexstar mount will take??

Gavin:)

[sgazer]

do you mean the SE mount? That comes with a 8" SCT which are about 6kg, on an SLT I had a C80-ED, Canon 300d, Mintron and lens, so about 3kg. It worked ok, but was pushing it a bit for imaging.

[step_hen]

From Gavins sig i think he is refering to the slt mount. I think the heaviest scope these are sold with are 130mm Newts- not sure what one weighs though!

Stephen

[sgazer]

doh, yes, should have read that. I think the 102 frac and 300d should work nicely for 30s'ish subs if that's what you are thinking Gavin.

[tarqs101]

That's brill, cheers.

Do you think the CG-4 mount would be more stable and have a larger payload as there is a good deal on ebay at the mo?

[jgs001]

I was able to get 2 minutes with my st80 on my sly with my 450d, I think that's about 1.5kg. With the c89ed I was only able to hey 15 seconds but that combo is nearer 3kg and a lot longer. A ch4 being an eq mount would be a better bet though. Not ideal as possibly a little light but better than the sly.

[sgazer]

with the CG4 you wouldn't suffer from field rotation as it's an EQ mount, however you can get 30s-2min exposures without field rotation anyway on an ALT/AZ (providing the tracking is good and depending where it is pointing in the sky) which may be all you could hope for on the CG4 without guiding.

[jgs001]

As you have the SLT mount... I'd suggest just giving it a try and see how you get on. One thing you could always do... remove the OTA, bye a dovetail, mount the camera and a lens on the dovetail and use that.

[tarqs101]

Never thought of that John,

Is there a way I could make the SLT mount more stable?

I'm sure I remember reading a while back that it is possible to fill the legs with sand??!!

Gavin

[tarqs101]

with the CG4 you wouldn't suffer from field rotation as it's an EQ mount, however you can get 30s-2min exposures without field rotation anyway on an ALT/AZ (providing the tracking is good and depending where it is pointing in the sky) which may be all you could hope for on the CG4 without guiding.

Thanks for the reply. The mount is very acurate at tracking, keeping Saturn in the FoV of a 6mm and 2x barlow for over half an hour without adjustment!

So, quite good.

Gavin