Focus pre and post slew

[Rodd]

I have no real interest in completing either of these images in narrowband but I had nothing else to shoot really--the Moon was at 71% and high, and I had completed most of the available targets recently--I will revisit, but not quite ready to do so.  Not imaging at all?  Well that just wouldn't do.  The other parameter that I needed to suit was I had to get up early for work in the morning so I could not image all night.  So I picked a target (cave) that I could image until about 12:00--then I would slew to the Cone and let the rig run all night, got up and turn it off before work.  I had to make sure there was no chance of a pier collision (tripod in my case), and no chance of rain.  I was set.  I had recently started using the temperature compensation feature in my focus kit--which does a remarkably apt job of maintaining focus through temperature changes once a model is made.  But--my FWHM values just before changing to the Cone were very good for me--I new no focus tweak would likely result in an improvement.  But--the subs of the Cone had a FWHM of at least 1 arcsec greater than the Cave.  At 5 am I refocused and sure enough--brought down the FWHM by 1 arcsec.  Perhaps this is the case of the TAK focuser shifting ever so slightly?  Perhaps a Starlight instruments would not have done so?  I know I should have checked focus after the slew--but time was not available.  So--the question--is the large FWHM visible in the cone image?  I was going to delete the data, but decided to go ahead and process it.   In the end I have learned a valuable lesson.....Always refocus after a slew.

The cave image took quite allot of processing to get to this point--it has 49 5min subs, shot with the FSQ 106 and ASI 1600 under good conditions.  I was a bit surprised how noisy it came out.  At least focus was good.  Double Edit--the subs came out virtually noise free!  This brings up a point I tried to make a while agao--why are some parts of the sky inherently noisy and others not.....at least for me.

Cone image--not much processing at all.  The FWHM tells me the focus was off (confirmed with B-Mask)  but not sure it looks out of focus.  The question is--are the stars obviously bloated?  EDIT--The cone has 50 5 min subs

[RichLD]

The Cone image looks great to me - dare I say it looks sharper to my eye than The Cave, which I know doesn't stack up scientifically but...

Both are lovely BTW!

[HunterHarling]

The cone is my favorite. Both are great though. 

[tomato]

All I can say is if I had captured that data, it wouldn’t be going near the deleted files bin anytime soon.?

[Rodd]

6 hours ago, RichLD said:

The Cone image looks great to me - dare I say it looks sharper to my eye than The Cave, which I know doesn't stack up scientifically but...

Both are lovely BTW!

Thanks Rich--another lesson I learned....don't delete your data, you never know

Rodd

[Rodd]

5 hours ago, HunterHarling said:

The cone is my favorite. Both are great though. 

Thanks Hunter......I plan on getting this target LRGB when the Moon sets

Rodd

[Rodd]

3 hours ago, tomato said:

All I can say is if I had captured that data, it wouldn’t be going near the deleted files bin anytime soon.?

Thanks Tomato--I am glas I refraoined.

Rodd

[toxic]

both are great images Rodd if only my data could be that good 

[Rodd]

4 minutes ago, toxic said:

both are great images Rodd if only my data could be that good 

Thanks Chris--I guess numbers are deceiving

Rodd