I'm curious as to what the seasoned imagers on the list use when selecting a guide star, specifically, swapping an eyepiece parfocal with the autoguider, or a flip-mirror? I'm also guessing that Newtonian users don't have the back-focus to use the flip mirror. Thanks!
Chuck, I just use my Starfish autoguider with a MiniBorg guide scope. I don't swap out an eyepiece because there really is no need. I find and frame the selected object on the main camera chip, and then take an image with the autoguider. I nearly always have many suitable guide stars to choose from on the guide camera chip. I just pick one... calibrate the guider with MaxIm (which takes about 1 minute) and start autoguiding. I have much better luck with a separate guide scope than I had when guiding through the filters. The filters made it much harder to find a guide star, especially when using a narrowband filter. The separate guide scope is much better, but bring in the possibility of differential flexure between the guide scope and the main scope. It requires a really solid mounting arrangement and a good scope (mirror that doesn't flop around, etc.). That is my 2-cents worth. Tyler -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Thursday, March 31, 2011 11:48 AM To: Utah Astronomy Subject: [Utah-astronomy] Autoguider use I'm curious as to what the seasoned imagers on the list use when selecting a guide star, specifically, swapping an eyepiece parfocal with the autoguider, or a flip-mirror? I'm also guessing that Newtonian users don't have the back-focus to use the flip mirror. Thanks! _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
Chuck, I'm more half-baked than seasoned. But I use PHD Guiding software with an Orion StarShoot autoguider hooked to an Orion ShortTube 80 mm guidescope; the guidescope is firmly attached to the top of my LX200GPS 12" by way of the rings you so kindly modified for me. Best wishes, Joe --- On Thu, 3/31/11, Chuck Hards <chuck.hards@gmail.com> wrote:
From: Chuck Hards <chuck.hards@gmail.com> Subject: [Utah-astronomy] Autoguider use To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Thursday, March 31, 2011, 11:47 AM I'm curious as to what the seasoned imagers on the list use when selecting a guide star, specifically, swapping an eyepiece parfocal with the autoguider, or a flip-mirror?
I'm also guessing that Newtonian users don't have the back-focus to use the flip mirror.
Thanks!
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Hi Chuck, Unlike Tyler and Joe I've never used a separate guide scope. I used to use an off-axis guider (and still have it for sale cheap if anyone needs one) but ever since I got an imager with a built in guide chip that's all I've ever used. patrick On 31 Mar 2011, at 11:47, Chuck Hards wrote:
I'm curious as to what the seasoned imagers on the list use when selecting a guide star, specifically, swapping an eyepiece parfocal with the autoguider, or a flip-mirror?
I'm also guessing that Newtonian users don't have the back-focus to use the flip mirror.
Thanks!
Patrick, I would need you to mail me the off-axis guider (increase in price, of course), but I’m interested in purchasing it. E-mail me at my personal address and give me a quote. Dave On Apr 1, 2011, at 12:22 AM, Patrick Wiggins wrote:
Hi Chuck,
Unlike Tyler and Joe I've never used a separate guide scope.
I used to use an off-axis guider (and still have it for sale cheap if anyone needs one) but ever since I got an imager with a built in guide chip that's all I've ever used.
patrick
On 31 Mar 2011, at 11:47, Chuck Hards wrote:
I'm curious as to what the seasoned imagers on the list use when selecting a guide star, specifically, swapping an eyepiece parfocal with the autoguider, or a flip-mirror?
I'm also guessing that Newtonian users don't have the back-focus to use the flip mirror.
Thanks!
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Hi gang, I haven't had time for non-work-related email for the past few days so I'm way behind on list messages (over 500 unread from last year alone, lol). My apologies and thanks to those who responded and I'll reply as time permits.
OK, back to the land of the living for a few minutes. Celestron recommends using a parfocal eyepiece (they include a clamp ring for an eyepiece supplied by the user) to find and focus the guidestar. My thought was, instead of swapping-out the eyepiece for the autoguider, to use a flip mirror and be able to go back and forth instantly. It sounds like, once you know where the guider focuses, the eyepiece might not be necessary at all. This is where a micrometer focuser comes in handy. Also eliminating the flip mirror means you don't need a lot of extra in-travel between the focal plane and the fully racked-in focuser position. I still have my old Lumicon off-axis guider in a 2" format. That little item was worth it's weight in gold when imaging with film, although I have to tell you that guide stars near the edge of the FOV are pretty comatic with very fast f-ratio scopes. Using the Lumicon coma corrector helped reduce that condition tremendously (also used visually, I'm glad I have it). You're probably only getting about 50% illumination out near the edge, especially with a reflector, but that's still a lot more aperture than a 50mm or 80mm guide scope when used with say, an 8" objective. One of these days, clear dark skies will coincide with my free time and I'll actually get to try out the NexGuide.
participants (5)
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Chuck Hards -
Dave Gary -
Joe Bauman -
Patrick Wiggins -
Tyler Allred