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Photo of the Andromeda Galaxy

  1. Oct 20, 2005 #1


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    New pics. These are a month old, but I forgot to upload them. They are from Sept 29. That was the first night it got really cold and I drove to the Poconos to set up shop, so while the sky was very clear and very dark, it was also very windy.

    First is another shot at the Andromeda Galaxy. The data actually isn't much better than the last time (though there are more pics), but I'm getting better at image processing - particularly with removing light pollution. So the result is considerably better than the last.

    Next is Mars, obviously. I have a nice quality 5x barlow that I just started using for planetary work. That puts me waaay above the theoretical maximum magnification for my scope, but the results still look good. I'm pretty sure the haze to the bottom right is from the wind, not Mars' atmosphere.

    Third is a shot I took with regular still-photo camera. I didn't realize until just now that the reason I can't see the Milky-Way is because I didn't point the camera at a very bright part of it! So I have an overexposed, noisy (even though that's a stack of 5x15s, unguided), and not altogether interesting photo. But I'm showing everything so people can learn from my mistakes. I think the ISO was 400, and I guess it needs to be more like 100 to reduce the noise. If you can't tell what the photo is, it's Cassiopeia, with the Andromeda Galaxy at the top, left of center, and the Perseus Double Cluster in the middle of the upper-right quadrant. I went once-through with Photoshop to remove light pollution and amp effects, which is the reason for the funny coloring at the top-left. If I feel like it, I'll see if I can improve it, but it may not be interesting enough to be worth the effort (except for practice).

    Update on my tracking issues: I was told by a Meade rep that my problem (described in earlier posts) is periodic error. I'm not so sure because while it seems to be periodic, it is a very rapid shift (less than a second), not a smooth sine-wave-type error. But my scope has periodic error correction (with a firmware update), so I'll see if I can get it to work. So far, no success - I want the camera to guide the scope to make the corrections accurate and fast, but I can't get the camera to guide it. If anyone has any suggestions....

    I have my DSI software interfacing with my scope and I can slew the scope manually using the software, but it won't guide. I have a suspicion that it's because of the orientation of the camera not matching what the software thinks the orientation of the camera is, but I'm not sure. See, the problem is that when the camera is looking through the top of the diagonal, they want it oriented to the right: which means taking off the finderscope, which I will not do. And when the camera is attached to the camera port in the back, they want it oriented facing down, which makes it hit the base and severely limits the range of motion. Next time I get the chance, I'll find a lower star to point at, but I'd really like to be able to look through a barlow lens - that would improve the accuracy, right? The software has a box where you enter the focal length, so it knows exactly how much tracking error it is seeing on the screen. But then, doesn't a Barlow cause the image to be mirrored? I can never keep these things straight...

    One thing, the documentation on this stuff is terrible. I guess once I run the PEC training module on the scope and have the camera guide it, it should work.

    Another issue, my scope got progressively sloppier over the summer as grease migrated from the gears to the clutches, to the point where no amount of tightening (short of breaking something) would keep the drives solidly locked.. I cleaned it up last night, and it feels a lot better. I can't imagine someone who is afraid of taking it apart being able to use it.

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    Last edited: Oct 20, 2005
  2. jcsd
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