oag setup??

[iwols]

hi does my oag need setting up apart from putting in the chain and getting good focus,does it need aligning in any way with my main scope camera cheers

[vlaiv]

Nothing special, just make sure that OAG prism is deep enough in light cone to pick up enough light, but not deep enough to cast shadow on sensor. It is usually best to place prism next to longer sensor edge as that way it can be closer to optical axis without casting shadow on chip.

[iwols]

thanks thats what i have done,does the orintation matter

[vlaiv]

2 minutes ago, iwols said:

thanks thats what i have done,does the orintation matter

In what sense? Some OAGs are made so you can rotate pick off prism - this is used if you can't find suitable guide star. I did not have any issues with mine OAG so far and I just put it on longer sensor edge. I don't particularly pay attention to way it's "sticking out" of the optical train - too small mass to make difference to balance with my mount. But you might choose certain orientation like parallel to DEC axis (pointing "down" when scope is parked).

[RolandKol]

And as you will be playing and wasting time focusing OAG cam,

keep in mind, it is better to rotate camera in a holder in such a way, - that once PHD drifts for example North, - star should go Vertical or Horizontal, but not diagonall.

Not sure, how much value it has, but PHD2 developer suggests it as a good practice.

[iwols]

suppose the guide camera can be any angle as long as a recalibration in phd is performed when it is altered??

[RolandKol]

yep, in fact, I have not noticed any particular advantage while camera was placed as advised.

So I just wasted my time, as I had my stars moving diagonal initially and had to re-focus and re-calibrate.

However, if you have not yet focused it, - you can place and focus it as PHD2 advises, without any additional waste of time (or with a minimal loss).