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Old February 5th 08, 08:56 PM posted to alt.binaries.pictures.astro
Rick Johnson[_3_]
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Posts: 262
Default ASTRO: Mars Last image of 2007

My setup is lousy for planets. A web cam is by far the best way to go
as you can get hundreds of shots, stack and process the best and if your
focal length is long enough get a pretty good shot. A mono CD is about
the worst instrument for planetary work. Add to that that my system has
no way to insert a barlow and I'm really up the creek when it comes to
planetary work. But I did try Mars at the end of December anyway. My
camera can only take about one shot every 40 seconds so just taking 4
lum shots and 4 each of each color takes nearly 15 minutes. By then
Mars has rotated enough things don't line up well. I tried three such
series. Each series had to stand alone as things had moved too much.
Of course the best blue frame was in one series, the best luminosity
frame another etc. Stacking only lost resolution. So I picked the best
luminosity frame then used the best of each color from that series and
processed that. Going RGB didn't work as one color was pretty lousy in
each of the three series. So I went LRGB. Then since I can't use a
barlow I just doubled the size of the image. Crude but it does seem to
make detail easier to see. Of course the bland hemisphere was showing
the only night it was clear with somewhat good seeing.

My header only records exposure time to two digits and those were 0.00
so I don't know my exposure. It will take down to 0.001. In any case
it was very short and of course binned 1x1 another rarity for me. No
darks or flats were used. Mars was so bright it was far above any need
for either and I had no dark or flat for this binning mode (one quarter
frame binned 1x1) anyway.

What I should have done is tried longer exposures and see if I could
pull out Phobos and Deimos. My system is better suited for that.

Rick

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