Flame Nebula

[PhilB]

This is 20 x 60s stacked in DSS and final processed in CS2. Taken though 80mm f6.1 'scope fitted with Atik 320e with HA filter. Conditions, on 8 Jan last, were rather poor, with a fine mist making it difficult to get a halfway decent final image; it's been something of a fight:

[Carole]

That's a nice big flame Phil and for 60 sec exposures showing very well, not over processed. 
Well done.

If the FOV had been a bit wider you'de have got the horsehead too.
Did you take any darks? 

Carole

[Mike]

Pretty nice Phil considering the conditions. Can you stretch to 2 or 3 mins ?

[Fay]

well done Phil, try for longer exposures next time, you have it in your sights 

[RobertM]

Good attempt Phil despite the mist which is probably causing a lot of that noise you're having to deal with.

You can try longer exposures or many short ones but in either case it will be the total exposure time that counts.  I think you've done well for 20 mins of total exposure but you'd see much more detail and a cleaner image if you were to do 60-80 mins total or preferably more if you can.  There's also a little tracking error or coma in there too but I can't tell which.

Is that the full frame or crop ?

Hope that helps
Robert

[PhilB]

Thanks, everyone.

I'll add a 0.5 FR into the mix next time to increase the field. The darks and flats didn't seem to help too much on this occasion.

Tracking has been an issue, hence the trailed stars. However, I spent the next night aligning the mount which can now hold stars centred for at least 5 minutes without any noticeable movement. It should now be possible for me to increase the exposure times.

The final image was lightly cropped.

[MarkS]

Great image Phil.  It's rare to see one of the flame nebula in its own right!  You must be pleased with that image given the conditions and the limited total exposure.  Nicely processed as well.

I've just looked up the Atik 320e.  It's a great small chip camera using a Sony HAD chip with an incredibly low read noise (3e-).

A few technical comments:
1) Check each individual sub for that star distortion.  It looks a bit like coma or some other optical aberration to me.  If every sub shows the same distortion then it may not be a guiding problem.
2) The Sony HAD chip (especially when cooled) has almost no dark current so I'm not surprised that darks did not help
3) Unless you have dust on your chip (which you don't appear to), flats will also make no difference when using such a small chip in your optical train because there will be no vignetting.

Mark

[RobertM]

I'd agree with Mark about the Darks and flats, those Sony chips have such low dark current that they are not necessary and the chip is quite small.  I read an article a few years ago where the author found that darks could actually contribute to image noise in cameras with those Sony CCD's.  I know some persist in doing darks anyway but why waste time doing unnecessary darks when you can be catching more lights

[PhilB]

The manufactures blurb does suggest that darks aren't necessary, but having been caught out by over the top claims before, I was unsure whether to believe it! I'll give it a try and see what the results are.

I'll also have a look through the light frames to see what the stars look like. I'm hoping that this is a tracking problem as the 'scope in question is a refractor and any optical problem might be nigh on impossible to fix.