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Sunday, September 14, 2008
Tokina AT-X 300 f2.8 is a big and heavy lens.
Diameter of the main lens is 112mm.
Optical quality is very good. At f2.8 stars are absolute pinpoints to very corner of the
imaging area of my APS size camera.
STAR TEST IMAGES, LENS FULL OPEN @ f2.8:
Here is five images from cornes and the center of the image.
Image is just stacked (5 x 900s) and stretched, no other image processing methods are used.
Some brighter stars may have some distortion, but it's cauced by guiding and polar alignment errors.
-This is a single 900s H-alpha filtered, flat and bias calibrated frame.
Red pixels only, hence 1/4 size from original frame.
Mildly stretched under CCDStack software due the 8bit format, no other prcessing.