木星 月惑星研究会 関西支部
Jupiter Image 2006/05/29(UT)
Fabio Carvalho,Randy Tatum,David Arditti
F.Carvalho,R.Tatum,D.Arditti
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Fabio Carvalho (Newtonian 254mm Philips ToUcam PRO II) |
2006/05/29 00:21(UT) - 00:50(UT)
D. 43.8"
Newtonian 254mm f/6 at f/24
Philips Toucam Pro II
Seeing 7/10 Trans. 9/10
2006/05/29 02:59(UT) - 03:27(UT)
D. 43.7"
Newtonian 254mm f/6 at f/24
Philips Toucam Pro II
Seeing 6-7/10 Trans. 8/10
Notice the phases of Ganymedes while it enters in the
cone of shade of Jupiter!
[Fabio Carvalho : Assis,Brazil]
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Randy Tatum(250mm f/10 refl:ToUcam Pro) |
[ Randy Tatum,Richmond,VA U.S.A]
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David Arditti (250mm Dall-Kirkham Cassegrain:ATK camera) |
I had quite good seeing this night, and have made a technical comparison between various types of filters.
At the top, the RGB and RRGB images are the same image, but different processing.
The images below go in a succession of filters through G (IR block), R (no block), broadband infrared (Baader dyed glass filter 685nm), narrowband infrared (Astronomik interference filter 742 nm) and further into the infrared (Astronomik interference filter 807 nm).
Of course, the trouble as always was that seeing did not stay constant, but deteriorated by the time the narrowband images were taken. The trouble with these filters is that though, theoretically, they might be expected to provide more sharpness because they completely exclude the visible and near IR, because they transmit much less radiation, either the gain has to be turned up or the frame rate decreased, both of which mitigate against higher resolution. Possibly with a larger aperture they would be more beneficial.
Between the Baader IR and the Astronomik 742, gain has to be increased by about 20% (working in the upper half of the Toucam gain scale). With the Astronomik 807 filter, at 10 fps, a bright image cannot be obtained on the screen with my 10" aperture. The stacked results, nevertheless, are not too bad.
[David Arditti: Edgware Middlesex HA8 5LW: United Kingdom]
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