Quick Cocoon IC5146

[MarkS]

Here's a quick test image I took on Wednesday night.  It's the Cocoon Nebula taken on Wednesday evening using my new Starizona LF corrector on the Celestron C11 - the LF means "Large Format".  It's the only SCT corrector that covers the sensor of a full frame camera.  As always, I was using the (full frame) H-alpha modified Sony A7S.

This is only 70minutes of exposure taken in 30sec subs at ISO 10000.  The other 90minutes of data was unusable because of the passing clouds.

I've cropped the image because the stars go quite squiffy on the right hand side - I still have some adjustments to make to the collimation and sensor spacing but the nights are not yet long enough.



If you really want to see the squiffy stars, the full version is here:
http://www.markshelley.co.uk/Astronomy/2018/Cocoon20180718_full.jpg

Apparently the alignment of this corrector is quite critical and I'm obviously not quite there yet

Mark

[Carole]

Snap. 

I didn't realise you were planning to do this so soon after your recent comments on mine.

As always, a lovely image Mark, I do think this target is better appreciated close up.

Now I have seen yours I have gone back and tweaked my "close up" some more, (see my post)

Carole

[MarkS]

Snap. 

I didn't realise you were planning to do this so soon after your recent comments on mine.

As always, a lovely image Mark, I do think this target is better appreciated close up.

Now I have seen yours I have gone back and tweaked my "close up" some more, (see my post)

Carole

Thanks.  Your version is looking even better now!

My plan is to repeat some of my C11 images from 10 years ago to show the difference that the latest sensors can make.  The Cocoon is one of those. 

Here is the one from 10 years ago taken with the modified Canon 350D: 



It used nearly 3 hours of data and I still had to bin it right down just to reduce noise to an acceptable level.  The new image shows fainter structures and many more stars and the imaging time was much shorter.

Technology moves on ...

Mark

[Carole]

Yes, good comparison.

How do you Bin DSLR data Mark?

Carole

[MarkS]

How do you Bin DSLR data Mark?

Most astro post-processing packages have a resample functionality that averages together neighbouring pixels.  Photoshop will also do it at a pinch - apply a custom filter - a 2x2 box populated with one's - before downsampling.

Mark

[Carole]

Thanks

[ApophisAstros]

All nice images, love the dark nebulas.
Roger