Quote:
Originally Posted by Octane
Bert,
Pinpoint stars and great nebulosity detail.
However, there is a severe glow to the top left, and purple/green noise scattered throughout the image, especially at the lower edge and right edge frames. What is it? Is it a bi-product of HDR (LDR)?
Regards,
Humayun
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It is a combination of factors Humayun. With a full frame sensor at this focal length (290mm)there is vignetting. The vignetting can introduce gradients and increase apparent noise especially in the corners. As I had only two 16m exposures noise could not be minimised by median stacking. The HDR process is very good at showing the dim nebulosity at the same time as the very bright stars without saturating them. It also is very good at faithfully showing any noise that is present.
I did not use any noise suppression or GradientXterminator. More data is needed at the 16m exposure level. With luck the weather will allow me to get this data.
Here is a maximum quality jpg cropped to what a C sensor sized camera would give. 7MB
http://d1355990.i49.quadrahosting.co...08/swanegC.jpg
I have found nearly every optic I have both lenses and telescopes which perform very well with the Canon 20D are found wanting with the full frame of the Canon 5DH.
This proves again the first rule of the Universe. 'There is no free lunch.'
Bert