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chef_josh
member
Reged: 07/01/06
Posts: 22
Loc: New York
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I touched on this in Jerry's last post but thought that it would be better in its own thread. I read Thierry Legault's collimation technique and have had trouble getting satisfactory results due to fairly consistent poor seeing here in the Northeast US. I've never seen anything better than a 5 on a 1-10 seeing scale. This is even after I'm been outside for 3 hours, and I keep my scope in the garage, so I don't think its a temperature thing. Seeing the effect on resolution that collimation off by a small amount can produce made me want to quest for the perfect collimation. I know about the LX200R 10" collimation issues, however, I don't have any problem getting the first step (out of focus star) on both sides of focus. It's when I magnify by 400X the image is very shaky and I'm unable to accurately determine collimation. I brought up laser collimation as a possibility. Also, I've tried CCD inspector with poor results; I'm unable to get 100 stars in the CCD picture with my DSI pro (maybe light polluted skies), perhaps a focal reducer would help. If anyone has suggestions they would be greatly appreciated.
Josh
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Meade ETX-90AT, LX200R 8"
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2357
Loc: Boothwyn, PA
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Are you sure it's seeing causing the shakiness? It could also be mount shakiness? Do you have vibration isolation pads? Try setting up on grass instead of concrete? Are you near a freight train like I am? 
I think finishing off collimation at 400x with a star test is better than a laser collimator - the star test should always be usd to judge collimation in the end.
If you go to a Messier Open cluster - you should get lots of stars in the CCD picture with an exposure of a couple seconds.
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX 
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chef_josh
member
Reged: 07/01/06
Posts: 22
Loc: New York
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What I meant by shakiness was poor seeing, usally about a 3 on the Pickering scale.
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Meade ETX-90AT, LX200R 8"
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2357
Loc: Boothwyn, PA
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if definitely poor seeing then theres not much you can do.
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
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chef_josh
member
Reged: 07/01/06
Posts: 22
Loc: New York
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I'll try using an open cluster in CCD inspector, thanks for the advice Joseph. I was also hoping to hear from someone with experience in collimating a LX200 with a laser. Does everyone in the Northeast experience the same poor seeing? I was told that the jet stream is usally overhead here, which causes the constant turbulance.
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Meade ETX-90AT, LX200R 8"
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Joseph Gillman
Carpal Tunnel
Reged: 12/06/05
Posts: 2357
Loc: Boothwyn, PA
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i'm near philly, and last weekend and this past week we had better seing here than usual. It also helped that my neighbor didn't turn his porch light on like usual (im in a townhouse so the light is literally RIGHT there).
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Meade RCX400 30cm --
People dont like when I stick up for Meade but they're just jealous of my RCX
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Bill W.
Pooh-Bah
Reged: 10/09/05
Posts: 1437
Loc: Western PA, USA
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I have heard very little good about SCT laser collimators. I would save my money if I were you. I personally get my collimation as close as I can with a recitle eyepiece. I use the recitle eyepiece so I know I am centered on my field of view. Then I check my collimation away from the center of my field of view. I check both sides of focus. Then I attach my imager and use the focus mode with a 2-4 second exposure. I point the scope to an area that has alot of stars that area spread out such as an open cluster. If you did a good job using the eyepiece your adjustments will be very small. If you thought of screw as a clock I am moving it only a minute at a time in either direction. It takes some practice but if you image it is a very effective way to collimate. I should say I own one of the LX200 f/6.3 scopes and they're are notorious for being a hard to collimate because of the faster optics. But, using the above method I've been pleased with my results. I live in Pennsylvania and deal with the same upper atmosphere turbulance. Even at 133x my stars jump around some. If I pumped it up to 400x I would really be scratching my head. For me, using a imager has been a tremendous help.
-Bill
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Orion Atlas EQ-G (EQMOD), SBIG ST-2000XM & AO7
Stellarvue SV66ED
Skunk Hollow Observatory
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