Very large image of Carina in Colour+HA and HDR

[avandonk]

I had very good data for both colour and HA for Carina Nebula so I carefully combined them. Adding the HA helps to suppresss any light pollution in the red channel.
Below is an inverted HA done in HDR of the HA data used.

The colour can be seen in this thread
http://www.iceinspace.com.au/forum/showthread.php?t=24927

I nearly doubled the size of the image for RL enhancement as this leads to rounder small stars and the use of a more meaningful point spread function.
If this is not done the stars tend towards lovely squares. It is also an indication of the quality of the Canon super teles that such a widefield can be done of stars with this high resolution.

Very large image 5.3 MB
http://members.optusnet.com.au/avandonk1/CAR_C+HA_HDR.jpg

I also took jases advice and upped the blue a tad.

Let me know what you think. It has taken me three years to get to this point and I am sure I will be at it for longer to get better.

If you view this on your monitor by clicking the icon in the bottom right hand corner the full image is then 2.2 meters in width!

I forgot to add that the original tiff at this pixel size ie 7500x5367 was 235MB and looks much cleaner.


Bert

[ballaratdragons]

Wow Bert! The 5.5MB is a stunner!!!

Millions of stars visible, and the keyhole Neb is easily seen at full size.
Fantastic work :)

[Garyh]

A beauty Bert! that Ha data really enhances the image.
I compared it with one of my shots with just a 200mm lense and you can see so much more faint red stuff in your image..
Top stuff Bert!

[Ric]

Excellent Bert, that one is a real masterpiece.

Cheers

[jase]

Very nice Bert. The quantity of nebulosity captured is magnificent and colours look good. The key hole looks a little washed out, but still a classic presentation of a crowd pleaser. Well done.

[h0ughy]

I am part of the crowd and very pleased (read that as not easily pleased)

[avandonk]

Thanks all. Jase the keyhole may be washed out but just next to it Eta Carina can be seen clearly elongated with colour. The difference in brightness is huge but the HDR method seems to cope. Of course this depends on the exposure ranges in this case the image potentially has 18 bits of dynamic range or 262,144 levels compressed into first a 16 bit (65,536 levels) tiff and then after a bit of image processing finally converted to an 8 bit (256 levels)jpg that you see here.

Of course the HDR image is linear in response and when this is converted to a tiff with EasyHDR the logarithmic response of the human eye/brain is imposed on the data.

I would be interested to see what a 16 bit camera could do with this method. If you used the same number of exposure ranges ie 6 you would potentially have 22 bits or 4,194,304 linear levels.


Bert

[tornado33]

Very nice especially how you keep the inner detail with the HDR method.
Scott