Sunday, September 14, 2008
New Lens for astro imaging
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.
As seen in the images, there is no visible optical flaws!Some brighter stars may have some distortion, but it's cauced by guiding and polar alignment errors.
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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.
Tuesday, July 29, 2008
Comparison of Flame Nebula, with and without stars
This is an example of star removal technique.
Two images of the same target is presented here with and
without stars.
In starless image, the nebulosity is much more visible and some
forms can be seen only in this image.
This can be usefull technique to reweal very faint nebulosity hidden
in overwhelming starfields.
Click for large image.
Thursday, July 17, 2008
Sh2-240 Reprocessed
This was really hard to catch and process.
Somehow better now, I think.
The Sh2-240 (Simeis 147) is a very faint supernova remaint in Taurus.
The image is in false color to show hydrogen alpha emission.Original BW H-alpha image at the bottom
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IMAGING DETAILS
-Optics:
Canon FD 200mm f2.8 lens with full aperature
- Camera:
QHY8
- Platform and guiding:
LX200 GPS 12" with QHY5 guider and PHD-guiding
- Exposures:
10 x 3600s + 4 x 2700s + 3 x 900s H-alpha + Flats and Bias frames, no darks
exposure time so far 13h 45min.
- Filter:
Baader 7nm H-alp + IDAS LP for RGB
H-alpha
Wednesday, July 16, 2008
Veil Nebula, Western part (reprocessed)
Veil Nebula is a supernova remnant with large angular diameter.
Located about 1400 light years away in the constellation Cygnus.
This is a reprocessed version from Autumn 2007.
ED80 + QHY8, guiding LX200+QHY5, UHC-filter 4h+flats+bias.
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Eastern part of the Nebula can be seen here:
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