Quote:
Originally Posted by strongmanmike
He he nice write up Ray, I assume this post was instigated by some of my recent comments on the validity of deconvolution? 
The key here and the bit I am not sure of and questioning is how does the decon algorithm apply a PSF to the non stella detail when the PSF was measured and created from looking at a star..?
Mike |
yuup
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the PSF applies to the whole image, not just the stars. The whole image is blurred by the atmosphere and the optics, so the whole image should be subjected to the reverse process of deconvolution.
An easy way to measure a system Point Spread is to pass light from a point source through the system and what comes out the other end is the PSF - in astro imaging, isolated non-saturated stars provide the point sources you need. Using the stars is just a convenient way to get the PSF for the imaging conditions, but once you have it, it applies to the whole image. Deconvolution is widely applied in microscopy, where there are no readily available point sources. PSF can be determined using tiny fluorescent beads to create artificial equivalents of the stars used in astronomy, but once PSF is determined using such a source, it is applied to the normal images - same thing in astronomy.
I would be most interested in your view on where deconvolution fits in. It does have wide application for technical analysis, but when used as designed, it produces results that do not fit into the "pretty pictures" mould. Maybe there can be a place in our hobby for images that extend resolution at the expense of "niceness" in the rest of the image. I think that there is a lot that can be done to move amateur images into higher resolution regimes, but suspect that there might be a fair bit of resistance to such an approach. Might be fun to try to push the boundaries a bit though. Regards Ray