Dumbell Nebula - M27

Three images on TP 2415 hyp. stacked (2 x 30 min. plus 1 x 45 min.), taken last year. One image is good, one is a bit out of focus and the third shows significant streaks due to guiding insufficience. After stacking the image was deconvolved with the intention to reduce the various kinds of blurs in the image. Um, I forgot wether I applied a noise filter after that or not - although I did the processing yesterday . Modified the histogram.
I shouldn't use the coma corrector for tiny objects like this one, since they are so small, they are hardly affected by astigmatism and coma wich do not occur in the center of a newtons fov. But the corrector *blurs* the center to 12 µm spot size (while it corrects everything else down to 12 µm spot size). The following tele extender doubles this spot size . Why haven't I thougt about this before I made these images (the smallest stars in the image are equivalent to about 25 to 50 µm on the negatives)

Updated (03.03.2006): Added colour data from a very underexposed image on Kodak Ektachrome 400 (don't know the exact time ). Filtered the colour layer with the simple Photoshop dust and scratch filter and corrected the colour.

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Nikon FE with TP2415 hyp. and Kodak EL-2 (= Ektarchrome 400)
8 " GSO newtonian optics (f = 800 mm) in a very stable selfmade truss tube
manually guided @ D = 60 mm, f = 900 mm through a Baader Microguide eyepiece
coma corrector
Sigma 2x APO tele converter
modified EQ-6 mount
13 nm FWHM H-alpha filter

Photoshop (stacking, border and histogram)
Cadet (custom psf deconvolution)
Cartes du Ciel (background image and computer drive)