NGC 6823 and NGC 7000--a comparison in Ha

[ollypenrice]

Great! Paul Kummer and I worked on this region, and somewhat beyond it, last year and this. The Ha is certainly faint. I love that sea-horse like structure on the left.

Olly

[Rodd]

5 hours ago, ollypenrice said:

Great! Paul Kummer and I worked on this region, and somewhat beyond it, last year and this. The Ha is certainly faint. I love that sea-horse like structure on the left.

Olly

Thanks Olly--I didn't even know it existed prior to imaging.  I find planning a framing tricky sometime because for faint objects you need to shoot before you know whats there.  

Rodd

[ollypenrice]

9 hours ago, Rodd said:

Thanks Olly--I didn't even know it existed prior to imaging.  I find planning a framing tricky sometime because for faint objects you need to shoot before you know whats there.  

Rodd

But those are the best kind of objects! A sense of discovery...

Olly

[wimvb]

On 26/08/2018 at 18:54, Rodd said:

I suppose the STF is just that--same level of stretch (unless the software adjusts the stretch level in the auto stretch routine based on SNR or whatever).

Nope. STF is normally calculated for each image separately.

But you can apply the stf of the NA neb by dragging the triangle of the stf process window to the other image. Same goes for any other process, btw.

[Rodd]

On ‎01‎/‎09‎/‎2018 at 16:40, wimvb said:

Nope. STF is normally calculated for each image separately.

But you can apply the stf of the NA neb by dragging the triangle of the stf process window to the other image. Same goes for any other process, btw.

 

On ‎25‎/‎08‎/‎2018 at 13:48, vlaiv said:

On a side note, it looks like NGC 6820 is extremely dim object, have a look here:

http://www.astrokin.com/ngc-6820--ngc-6823.html

It looks like you need at least 30h to complete NB image of this object to be in area of "smooth". There is also RGB version of what is achievable in 3h - not much.

For some reason I could not include Vlaiv in the quote--wouldn't let me include quotes from different pages.  Any way- to be thorough--here is the final, stand alone Ha for NGC 6823.  149 5min subs.  Calibration was complicated by the fact that we were in a heat wave for a couple of the days--so I could not maintain -20 degrees.  The coldest I could get on 2 of the days was -17.5, which required shooting a set of darks at this temp (calibration using temperature scaling of the darks did not work well the first time I tried it with the ASI 1600--so I did not want to take the chance).  The 41 subs collected last night were during "no Moon" and man, what a difference!  The Full Moon subs and the no Moon subs are like night and day. 

 

 

[Rodd]

I thought it might be interesting to try drizzle integration with this data--there are allot of subs and I dithered every one, so it was a good test subject.  I do like the stars better--and  I like the image in general, except I do not like the size it is displayed at full resolution-  At 1:1 it is about the same as the non integrated 2:1.  So I down sampled the image prior to posting.  Not sure which I prefer.  The drizzle image is sharper, brighter, less soft.  And it seems to have more depth.  But the non drizzled image appears softer--less aggressive.