Shark Nebula in Cepheus

[MarkS]

Here's another load of dust in Cepheus.  Not as striking and 3D looking as the dust near the Iris Nebula but interesting all the same.

This has been my nemesis since last year when I discovered the coloured banding on the Sony A7S sensor.
http://forum.orpington-astronomy.org.uk/index.php?topic=10594.0

Shooting at ISO 10000 (under my conditions) pushes the peak of the back-of-camera histogram more than halfway across and this is sufficient to overcome that particular electronic noise.  So this image is 580 x 30sec at ISO 10000 shot over 2 nights, 9th and 29th August.  A total exposure time of nearly 5 hours with the H-alpha modified Sony A7S on Tak Epsilon 180ED.  SQM was 20.8 mag/arcsec2 both nights.  The image would certainly have come out much better under darker skies.



Larger version here:
http://www.markshelley.co.uk/Astronomy/2016/shark20160829v2.jpg

Just for fun, this is what a single sub looks like:


The Shark Nebula is something I always wanted to tackle after seeing an APOD from last year shot with the same scope: http://apod.nasa.gov/apod/ap150907.html
Maurice Toet did that one with 13 hours LRGB imaging using an Atik 11000 in 10 minute subs on the Tak Epsilon under Olly's darker sky 21.4-21.6 mag/arcsec2.

I think this speaks volumes for the performance of the Sony A7S vs one of the best cooled mono cameras for wideband imaging

Mark

[Fay]

Love it Mark, never seen it before. the star colours are great!

Fay

[RobertM]

That's a wonderful image Mark, one of the best I've ever seen of this nebula.

Robert

[JohnP]

really superb - really like it - you should submit to APOD & make comparison to that earlier APOD. Unbelievable you can go from that single sub final image

[Carole]

Excellent work Mark, and well done on finding a way round the banding problem.

Carole

[Kenny]

Lovely image. Gobsmacked by what a single sub looks like!

[RachelC]

Shark Nebula! You are just making these up!

What an amazing image and such a beautiful capture.

I too am amazed at the before and after.

[The Thing]

I showed this to some of the 20 of us on this pilates/yoga 'retreat' thing we are on down here in Duras and they were gobsmacked. Then I told them it wasn't Hubble but Takubble that took it and their gobs were even more smacked. Superb and very very sharkey.