M42 in Colour and Narrowband HDR

avandonk · #1 18-10-2007, 07:55 AM

This is the result of combining the previous HA+O3 narrowband HDR image (150mm Achro) with a colour HDR image taken last night with the 100ED.
Exposures 30s,1,2,4,8,16 minute at 500 ISO. This potentially covers a dynamic range of 18 bits. That is why you can see the Trap and the faint outer dust and nebula at the same time.

They were combined in ImagesPlus by adding the corresponding colour channels.

Large image 1.3 MB
http://avandonkbl.bigblog.com.au/dat...1018073640.jpg

I think it is a rather pleasing result.

Bert

avandonk · #2 18-10-2007, 08:18 AM

Here are the colour and narrowband images.

Bert

xelasnave · #3 18-10-2007, 10:08 AM

Bert indeed a very pleasing result.
You have the knack of producing an image that looks very natural more in keeping with my visual impressions than any other poster.
I really like the images you produce.
I salute you.
alex

tornado33 · #4 18-10-2007, 09:53 PM

Well done Bert. 18 bits is a lot of levels. Gee how many photographic stops would 18 bits represent I wonder?
Scott

Ric · #5 18-10-2007, 10:42 PM

Fantastic image Bert, you certainly delivered the goods with this one.
Very detailed and visually pleasing.

Cheers

avandonk · #6 19-10-2007, 10:46 AM

Scott 18 bits IS 18 stops. Or if you assume the least significant bit is where the noise is then 17 bits or stops or 131,072 levels. EasyHDR can handle 96 bits. My next imaging will be to use the 300mm F2.8L and collect data at f/11, f/8, f/4, f/2.8 and then double the exposure for another five times at f/2.8. This with the 12 bits of the 5DH's sensor will give me 21 bits potentially. Lets call it 20 bits and then we will have one million levels!

Did you notice that the Trap is almost resolved?

Should be an interesting experiment.

Bert

Rodstar (Rod) · #7 19-10-2007, 10:56 AM

Bert, it sure is hard to image M42, doing justice to the nuances of the nebulosity, without the trap stars becoming too washed out. You seem to have found the right balance, as I can still make out the A, B, C and D.

Nice image!

avandonk · #8 19-10-2007, 12:55 PM

Rod here is a crop of an eight second exposure at 500ISO.

Bert

Rodstar (Rod) · #9 19-10-2007, 03:04 PM

Thanks Bert, even just for 8 seconds, and the 4 main trap stars are so bright their glare completely obscures E & F! Man, that is one hard object to image.