Any Ideas?

[Kaliska]

Ok, so I'm still very green around the ears here, but any idea whats happening here?

I'm taking 300sec lights, PHD guided with a GP-CAM on an ST-80, SW80ED on a AZEQ6 GT and getting these double stars...and this is happening on all of them so far.

[Tim]

Does your guiding graph show any aggressive corrections?

Where in the sky was your target, or what were you shooting?

How good is the balance on your mount?

Is it windy? Do you perhaps have any trailing cables that might snag or move in the wind?

What do short, say 30 second exposures look like? What if you take 20 x 30 seconds and compare the first to the last image?

There could be a few reasons for stars like that, are they over the whole image?

The answers to these questions might help us diagnose for you

[bobro]

I get a similar effect if focus is off.

[Kaliska]

My guiding graph was like a cross-section of the French Alps and the culprit was a snagged cable from the guide camera.

Another thing goes down on my ever increasing check list.