Upgrading to a new scope

Dave G,
The greater the ptp error, the harder the autoguiding has to work.
Regards,

:oops: :oops:

Spot on as usual Dave However I dont think it changes the conclusions drawn.

You're absolutely right Dave - your conclusions are still sound and your advice on the ball - as usual

Dave

Dave G,
The greater the ptp error, the harder the autoguiding has to work.
Regards,

I think Dave alluded to periodicity too. If you have two mounts with the same periodic error, the one that has a 'smoother' periodicity will be easier to guide rather than the one that is jumping quickly all over the place.

I guess I'm sweating the really small stuff though ... :oops:

Dave G,
The greater the ptp error, the harder the autoguiding has to work.

Agreed. It is obvious that the mount with the smaller PEC is far more desireable. What I am saying is that I don't beleive either of these mounts would have any trouble being autoguided, and I doubt if PEC will absolve either of the need to be autoguided. So assuming they do need to be guided then the question is are they both capable of doing so? Given that the CGE mount I got to use was capable of being autoguided to < 1" then the G11 will perform even better still. <1" guiding is better than the seeing on most nights, i'd simply go for the one with the better price.

<1" guiding is better than the seeing on most nights, i'd simply go for the one with the better price.

Amen