Another Helix...

[BruceG]

Hi all, I've been wanting to have a crack at this one for a couple of months now. Last night was pretty poor seeing and transparency but because it has been soooo cloudy here for so long, I ventured out to setup the rig anyway.
This is also the first time I took my DSLR off 1600 ISO to try to achieve less noise. I now see I should have given it at least another 2 hours. Anyway, I am happy with the fact that it is at least recognizable.
Any tips on adding more data another night will be welcomed.
Higher resolution here (http://www.astrobin.com/117745/B/)


29 x 4 minute subs at 800 ISO with 11 darks.

[raymo]

Hi Bruce, very nice. At this time of year the noise should be acceptable
using 1600.
raymo

[nebulosity.]

That's great Bruce! :thumbsup: Your going nice and deep.

Would be really awesome with a few more hours as you say, hope you get them.

Cheers
Jo

[BruceG]

Thanks Raymo & Jo, This is a challenge for my little refractor and obviously needs more time and effort. It's an amazing object though and I will try to get some more data if the weather improves.
Bruce.

[Rod771]

Looking good Bruce!

I've found ISO800 to be the sweet spot on my DSLR.

[Rex]

That's a top shot Bruce. Nice detail and your even starting to show the extended nebula around the bottom. Great job.

[BruceG]

Thanks Rod and Rex - a question without notice... As I haven't ever attempted to have a second imaging session and add it to the original, I take it I would subtract the new set of darks from the new set of lights and then stack these light frames with the original light frames? I would also use Align and rotate as the camera alignment will no doubt be different. I know that Backyard EOS has a function to line up subsequent shots but the camera I am using for this doesn't play with BYEOS (300D). Any suggestions or guidance will be gratefully accepted. :)
Bruce.

[Rex]

As for the darks it shouldn't matter that much from one session to the next providex the temp was approximately the same. Flats definately need to be taken each session and as you have mentioned the lights from each session need to be calibrated with only flats from the same session. As for combining i either stack all calibtated frames together or stacke each group and then combine the groups. I dont know if it makes any difference which way, i have had suçess doing it both ways. Just need to do the flats as mentioned. Hope that helps.

[BruceG]

Thanks Rex - unfortunately, being a novice, I have tried to keep it really simple and I have never taken a flat or bias frame. I have only taken some darks at the end of an imaging session. I do the darks after I stop guiding and park the scope. I will look at a method for flats next time (he says a little embarrassed).
Thanks again Rex.

[rustigsmed]

very nice bruce