Veil Nebula ISO 1600 140x30s unguided

[Daniel]

Hi All, finally got my camera modded and wow, what a difference, this part of the sky used to show up just black with stars before even guided on 5 min subs.

Anyway, despite getting my 12"SCT finally mounted, and guiding, I used the 80ED on its own for this, and considering I had to keep exposures under 30 secs and had to crank up the ISO to compensate i was suprised it came out ok.

also had a little time last week to take out the 12", stars looked a little more blurry than im used to, trying to work out wether it was slippage on the focus or just the longer focal length.

Anyway, here it is, ignore the squiggly lines, they appeared when I was trying out a new stacking method, but weren't there on an older stack, will re-stack when I get the time!

[RobertM]

Thats a great shot Daniel, could you post details of the camera, exposures and filter.

[Daniel]

Hi Robert. this is a mixture of about 40 30s ISO 800 subs and 100 30s ISO 1600 subs, taken with a modded Canon 40D using a CLS filter, seeing wasn't great, but transparency was one of the best nights I've seen in ages

Oh, and no darks or flats, still haven't had time to finish my light box

[JohnP]

Nice Daniel - Looks great - It'll be great to see how it comes out with longer subs... John

[Fay]

Fantastic Image Daniel. Well worth waiting for!

Fay

[MarkS]

That's image shows great promise Daniel.  Plenty of H-alpha!  If you can use guiding and use subs of around 5min then the image will come out an order of magnitude better.

Love the squiggles! Putting on my Sherlock Holmes hat I deduce the following about the periodic error on your mount:
1) It has an excellent sinusoidal characteristic
2) Peak to peak error around 60 arcseconds
3) Worm gear revolves once every 8 minutes
Also your mount wasn't very accurately polar aligned that night

So which mount are you using?

[Daniel]

that was done on the old CG5, it was very late in the day so we decided to go for the quick set up, quite glad we did too, I have a new appreciation for refractors!

[MarkS]

Makes sense - my old CG5 was also 60 arcsec peak to peak.