Dolphin Head Nebula - Sh2-308 with a DSLR

[MarsG76]

Hello Astronomers,

 

This is a center crop of Sh2-308, AKA The Dolphin Head Nebula in the constellation "Canis Major".

I was told that it is a waste of time to image this object with a DSLR. Apparently you need a cooled mono camera to get anything but I figured that my DSLR is cooled somewhat, modded and I have nothing to lose to try.... and IMHO the result is better than I was expecting it to be.

This was imaged through Baader 7.5nm HAlpha & OIII narrowband filters using my full spectrum modded and cooled Canon 40D DSLR and the Bosma 80mm refractor at 500mm focal length. This photo consists of 46x1200s of HII, 35x1200s and 2x600s of OIII and 36x60s, 32x150s and 21x210s of RGB subs @ ISO1600 for a total exposure time of 30.5 hours.

This object is very weak in HAlpha signal but very strong in OIII. The benefit of a color camera is that I captured two spectra lines in one exposure, I had OIII signal in the green channel while simultaneously captured HBeta in the blue channel in the stack. I assembled this image as HAlpha as Red, OIII as green and HBeta as blue.

The weak HAlpha signal outlined some parts of the bubble (the front of the dolphins head) so even if the HAlpha was weak, it was not a waste of time as it added detail to the image. 

One thing that is different with capturing this image than my usual imaging procedure was that during my last imaging project, my USB port on my DSLR failed, meaning that I couldn't dither my subs, which would make a bit of a difference. 

Thank for looking,

Clear Skies,

MG

[Adam1234]

Very nice

[MarkAR]

Excellent image, very well done.

[MarsG76]

On 03/06/2020 at 01:48, Adam1234 said:

Very nice

 

On 03/06/2020 at 01:52, MarkAR said:

Excellent image, very well done.

Thank you

 

[MartinB]

Ooh well done MG.  I'm not familiar with this nebula but it has a lovely delicacy to it in this image.

[x6gas]

Lovely image of a beautiful target...

[des anderson]

A fantastic image, and a big thumbs up from me. Des

[rubecula]

That's a loverly image, I've just added it to my to do list.  Thanks for sharing.

[MarsG76]

Thank you for the kind comments.

 

[MarsG76]

On 17/06/2020 at 22:50, rubecula said:

That's a loverly image, I've just added it to my to do list.  Thanks for sharing.

Thank you, I'm looking forward to seeing it, please tag me when you post it.

 

Edited June 18, 2020 by MarsG76