Paul Schroeder
member
Reged: 06/05/03
Posts: 90
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I would certainly agree with these comments. That being said, the visual images were also very impressive, much better than what I can see in Minnesota.
I think an experienced planetary observer could probably have gotten glimpses of many of the details in the smaller of the two Jupiter images above.
The challenge of course is that those views tend to come and go, whereas the processed images can capture pretty much everything that was there. I don't have the exact numbers handy, but each of the Jupiters was a stack of probably the best 500 from well over 1000 frames.
It's also interesting to note how a little scope like the Questar (with today's technology) can deliver images that compare quite favorably to images from much larger scopes only a few decades ago.
Best regards,
Paul
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Rat8bug
Pooh-Bah
Reged: 01/07/05
Posts: 1304
Loc: Michigan
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For group viewing, I suggest hooking up a video camera to project an image on a monitor. This avoids touching the telescope, and will illustrate the impact of seeing conditions on image clarity. The Supercircuits PC164 and color version are quite suited for this application.
http://www.barrie-tao.com/faq.html
Ciao....Barry
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Nikon D40/D50/D70 DSLR
WO 105mm Triplet APO
WO Zenithstar 66SD APO (Black 'n Blue)
WO 8 x 45mm APO Bino
UO 20 x 80mm Bino
Vixen 80SS Refractor
Orion 127mm Apex Maksutov
Vixen GP-DX with Skysensor 2000
SBIG STV and e-finder
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Paul Derby
newbie
Reged: 05/21/06
Posts: 4
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I would like to buy a Questar to helical focuser adapter that would allow me to use the Borg 7315 focuser on my 3.5" Questar made in 1991. I purchased a Borg 7315 focuser and a Borg 7316 nosepiece. I have a nosepiece adapter that screws into the Questar axial port, which is 30mm x 0.75 pitch threads.
This combination doesn't work because of the "slop and binding" in using thumb screws to hold the Borg 7316 into the nosepiece. For some reason s binding occurs and the helical focuser will not rotate smoothly.
Ideally, I would like to have a 7316 nosepiece that has the unthreaded end turned down to a bit less than 30mm and machined with .75mm threads. This way I could screw in the nosepiece directly into the axial port of the Questar.
Is it possible to buy a modified 7316 nosepiece that will work as an adapter from the Questar axial port to the 7315 Borg focuser?
I do not have access to a machine shop. I'm looking to buy the part that Barry made and described here: http://www.barrie-tao.com/questar_life.html
Is there an alternative that eliminates the "slip fit" coupling?
I'm trying to attach an Imaging Source camera to the axial port on my Questar. The Imaging Source cameras don't use T-Mounts so the Questar swivel couplings and extension tubes which I already own aren't the answer.
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NeilR
member
Reged: 02/18/08
Posts: 63
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Quote:
I'm trying to attach an Imaging Source camera to the axial port on my Questar. The Imaging Source cameras don't use T-Mounts so the Questar swivel couplings and extension tubes which I already own aren't the answer.
I've also been thinking about an Imaging source camera. It was my understanding that the IS cameras come with a 1 1/4" slip fit adapter, which could be attached to the Q's optional 1 1/4" adapter (that you apparently have). Am I missing something?
Neil
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Paul Derby
newbie
Reged: 05/21/06
Posts: 4
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The 1 1/4" slip fit adapter has too much slop in it to work effectively with the Borg helical focuser and nosepiece. A tight screw fitting would align all the pieces and hopefully get rid of the binding that occurs so the helical focuser would work smoothly.
I can gently lift the helical focuser into alignment and it works smoothly. If the helical focuser "hangs" there is binding when I try to focus. The slop in the setup is caused by the screw fittings using a nosepiece instead of precision threaded couplings.
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NeilR
member
Reged: 02/18/08
Posts: 63
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OK. I read your post as suggesting you wanted to attach the IS camera as directly to the axial port as possible, without the Borg focuser in between. Never having seen a Borg focuser, I have no clue what your problem is and I'm gracefully bowing out!
Neil
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Paul Derby
newbie
Reged: 05/21/06
Posts: 4
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The Borg focuser is a helical focuser that is put in-line between the Questar and the camera. It makes focusing MUCH easier than screwing around (pun intended) with the Questar for fine focus. So I have put the Borg helical focuser inbetween the camera and the Questar. It is having these slip fittings with the screws to hold things in place that are problematic. I'm trying to find threaded adapters to replace the slip fittings so the entire optical train is more stable, the "flex" is less, and also minimize the probability of having one of the fittings loosen resulting in the $870 camera falling to the ground.
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NeilR
member
Reged: 02/18/08
Posts: 63
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Thanks. I understand why you did what you did, although I have had good luck with the stock focuser. I just can't visualize your flex problem without having the gear. Which just means I surely can't help you.
As I get further into imaging I might want to try that focuser, which is why I'm watching the thread to see how this shakes out.
Neil
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Rat8bug
Pooh-Bah
Reged: 01/07/05
Posts: 1304
Loc: Michigan
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Prephaps I can chime in here. I was one of the original cheerleaders for the Borg 7315 Helical focuser. You will have to find a machinist to modify the nosepiece. Regarding the slip-fit adapter tube, one can tap another hole, for a 2-point anchor. Lastly, add a piece of brass sheet to act as a shim to hold the nosepiece. The advantage of using a helical focuser is that one can re-focus without changeing the FL. This is especially useful during photography, where images are to be stacked; prohibiting the FL changes.
http://www.barrie-tao.com/questar_life.html
Ciao...Barry
http
--------------------
Nikon D40/D50/D70 DSLR
WO 105mm Triplet APO
WO Zenithstar 66SD APO (Black 'n Blue)
WO 8 x 45mm APO Bino
UO 20 x 80mm Bino
Vixen 80SS Refractor
Orion 127mm Apex Maksutov
Vixen GP-DX with Skysensor 2000
SBIG STV and e-finder
|
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