[avandonk]

The first image is the jpg out of the camera of an eight minute exposure at an ISO of 1000 with the dust cover on the 100ED. The camera was in a Peltier fridge at 4 degrees C. Exif data is intact.

The second is a 100% crop from the center of the same image in max quality jpg from a tiff digitally developed with ImagesPlus with the following parameters

ImagesPlus Color Project v1.0
Final Image Saved As : I:\2008-01-15\DARKFRAME8m1000iso\CVT_IMG_0236_ d1.tif
User Comment :
Date: 1/16/2008 2:15
Operation : Read
Apply to: Red Green Blue
Operation : Digital Development
Background : 0
Background Weight : 1.01
Break-Point : 100
Sharpening Filter :None
Red Emphasis : r
Green Emphasis : g
Blue Emphasis : b

The third image is a crop of a jpg of the exact same area with the dust cover off same conditions as above ie eight minutes at an ISO of 1000. I always use ICNR which if anything tends to leave small dark 'holes' which disappear with median stacking if images have a slight drift. These holes are almost non existent if the camera is cooled to -12C.



Bert