NGC6992 in H-a and O-III

[derrickf]

The weather has certainly been unfriendly recently but I managed to collect 90 minutes each of H-alpha and O-III data in 10 minute subs in the cloud gaps.

I haven't been able to get any S-II data so this is a H-a O-III O-III composite

Equipment: EQ-6 Pro, SW Quattro 10CF + MPCC, Atik 383L+, TS filter drawer + Baader 1.25" filters.

The filter drawer system puts the filter surface very close to the nosepiece of the camera there is no noticeable vignetting with the 1.25" filters in the uncropped images even at the fast f/4 focal ratio of the Quattro (according to my calculation the diameter of the incoming light cone at the filter is about 27.4mm and the clear aperture of the filters is 27mm).

Thanks for looking

Derrick

[Mark72]

Fantastic DSO!

Just star colors are a bit to the green

Mark

[DirkSteele]

A lovely picture.

[derrickf]

Fantastic DSO!

Just star colors are a bit to the green

Mark

Thanks Mark.

I didn't pay any attention to the star colour since this is a narrowband bi-colour image and the star colours would be nearly impossible to get right. If the weather would cooperate I would finish of the NB data with S-II subs and maybe add a star layer from RGB data but with current weather and light nights that looks unlikely

Regards

Derrick

[The Sailor]

Beauty

Jim

[Mark72]

Derrick,

You can easily correct it; this skews it to the blue which is probably more natural

Mark

[derrickf]

Derrick,

You can easily correct it; this skews it to the blue which is probably more natural

Mark

Thanks again Mark - I'll try this on the uncompressed data.

Derrick

[nytecam]

Suberb result

[Gina]

Very good

[Rihard]

Wonderful Shot derrickf !!!

[astro mick]

Wow Derrick.

Puts my feeble effort to shame.

Great image.

Mick.

[4lefts]

fantastic. can i ask - do you shot any luminance? or is it literally 9x10mins ha, and 9x10 mins oiii?

thanks

stephen

[derrickf]

Thanks to everybody for your kind comments - they are much appreciated.

Mick, it's not really a question of one image being better than another - they are just different; your image is fine and I would be pleased with it. The major factors that differentiate our images are:

• Mine shows more detail because of the image scale (attributable to focal length and camera pixel size) - the image scale of mine is roughly 1 arcseconds per pixel whereas yours is more like 5.5 arseconds/pixel
  
• Mine is deeper because of the longer total exposure time and the large aperture , fast optics.
  

Stephen, no luminance just the 90 minutes each of H-a and O-III; the Quattro really sucks up the photons

Regards

Derrick

[MeyGray3833]

Nice image, love the size of the object in the frame.

[derrickf]

Thanks for the comments - following a suggestion from Mark72 I adjusted the colour balance to suppress the green cast - here's a revised image:

I like both but this version is beginning to grow on me ;-)

Regards

Derrick

[Mark72]

Well done!

[derrickf]

Thanks Mark

Actually HLVG did all the work :-)

Derrick

[ollypenrice]

The second version every time! PNs apart, green is rarely right in DS imaging. Well, that's just me.

Steaming signal and resolution.

I might just see what happened if you clipped three points off the back point...

Olly

Edit; or even black point...

[derrickf]

Thanks Olly, actually there was a quite a bit of movement for the blackpoint - here's how it comes out if I move it just to avoid clipping.

The Quattro and the Atik383L make a good combination IMO - just over 1 arcsecond / pixel (the fullsized version of this image has really good filamentary detail - this is a 50% reduction) and the Quattro really sucks up the photons.

Regards

Derrick

[ollypenrice]

I like it cut back that little bit. Remarkably close to RGB colour apart rom the stars.

Olly