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For information about the use of video cameras
for astronomy , see Jim Ferreira's
Videoastro
- site with lots of astrovideo images and links to related sites .
Putting the camera in prime focus
of the 200mm SCT seemed to be the best way to start . No moon available
, so the first image is of Jupiter with its Galilean moons . The image
shown is made by stacking 8 frames .
It was later I realized that the
recorder was in the "long-play" position (Murphy hasn't lived in vain)
, so the images were not in optimum quality . Nevertheless Jupiter with
the Galilean moons is not a too demanding project . The image was treated
with level adjustment and some Unsharp Mask , and was reduced to half size
.
Jupiter with Galilean moons , 10th November 1999
200mm SCT F/10
For my first attempt to image the
Moon I used the Astrovid 2000 from AVA with a Celestron C8 in prime focus
.
The image is a result of stacking
4 frames .
The first image was treated rather
harshly with ,at first a bit of Gaussian blur , followed by (too much)
Unsharp Mask (Photoshop) , and it shows , but well ,that is part of the
learning process .
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On the same first day some video of Jupiter itself was captured
, and recently the tape was recaptured and given some processing according
to the experience of August 2002 .
The result is considerably better than the image lower on this page , for two reasons :
1 ) The raw material on the video is better
2 ) The choosing of raw frames has been a lot more thorough
3 ) Improved image processing
The Moon on 15 Nov 1999 :
Mare Crisium region
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With the second image A little more
care was taken :
A little Unsharp Mask , followed
by setting levels , and at last , adjusting brightness and contrast .
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Mare Crisium , 15th November 1999
200mm SCT F/20 (I think) |
While the second image shows somewhat less details , it looks more natural . That is , after all ,the intention . However I notice some interlace lines at the edge of the image . But for a first attempt I find it acceptable .
The first Jupiter image was made
from 5 stacked frames taken from the first 6 seconds of the recording ,
made with the C8 , still manually tracked .
Seeing was , I think very poor
, with most fields completely unaligned in the frames . I have not yet
come to split the frames into fields .
The image has been level corrected
(histogram) , somewhat adjusted with brightness/contrast , and finally
a large amount of Unsharp Masking .
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Jupiter
, 15th November 1999
200mm SCT F/20 |
Though there is not a lot of detail
, It is possible to see two "knots" in the Northern Equatorial Belt .
The image is somewhat overprocessed
, in order to show this . The video footage was so poor I decided not to recapture in August 2002 .
Next test : Saturn .
Since there is less light from
Saturn I combined 32 frames , adjusted levels , brightness/contrast and
Unsharp Mask .The result is here :
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Saturn , 15th November 1999
200mm SCT F/20 |
Recaptured and reprocessed image from the same video tape September 2002 :
C8 200mm SCT @ F 20 , Astrovid 2000 , Hi8 recorder
22 raw frames selected from about 1000 ,
Stacked with Astrostack , including some Unsharp Mask and Lucy Richardson deconvolution
Processed in IRIS with Wavelet filtering and a little Unsharp Mask
Finally Levels adjustment in Photoshop
Thanks to Jim Ferreira and the Astrovideo
mailing list members for providing information and inspiration to get started
with video astronomy .
Last update : 01 September 2002
