M17 Omega Nebula (Swan Nebula)

[wayne anderson]

Still working on best autoguiding settings to use. The off axis guider seems to give very elongated stars with 2 bright sections one at each edge, its almost like guiding on a double star every time, the autoguider keeps losing the star and swaps to other side of the very elongated star.

M17 Omega Nebula:
30 x 120s subs (gain 90 bin2x2)
20 dark frames, Processed with Startools and gimp.

Scope: 12inch Meade LX200 at f6.3 (alt/az de-rotated)
Camera: ZWO ASI071MC pro
Guider: ZWO ASI120MM-S
ZWO ASIAIR pro

Larger image:
https://www.astrobin.com/full/69o7eo/0/

[PKay]

Hi Wayne

Aside from your guiding problems, you managed a result.

Well done.

[wayne anderson]

Thanks Peter, i think i found one reason why i have guiding issues with very elongated guide stars.

I noticed the OAG pick off prism shaft was too far down and guide camera mount assembly were not aligned so the guide star light was reaching the camera chip at an angle giving very elongated guide stars, all fixed now by raising the shaft just 2mm allowing guide camera assembly and shaft to grip better and be better aligned.

[ChrisV]

Very nice indeed Wayne! Got that camera singing.

I can't see the elongated stars that indicate tracking issues - although I'm looking at it on my crappy little phone. I see a few elongated ones on the lower left which suggests a bit of tilt in the camera or the imaging train somewhere with the weight of the camera?

[LostInSp_ce]

Great image Wayne I really like your choice of framing. I wouldn't worry too much about the guiding issues unless you pixel creep you barely notice them.

[Sunfish]

Looks very good to me. You have a great range of colour and detail. That is a difficult target to image.

The oval stars are barely noticeable even at the edges.My guiding will loose a star momentarily in the wind or high cloud but does not seem to create oval stars unevenly, more a general lack of sharpness.