Adapter for Orion SkyQuest XT8 telescope?

[Jon Ruyle]

Your friend needs a t-ring and a t-adapter. The t-ring fits to the camera, the t-adapter fits into the 2" focuser of the telescope. The t-ring connects to the t-adapter (I think that's how it works... I might have gotten them switched). You can get them at www.astronomics.com. You may want to call to check my facts and make sure the thing you get will work with the xt8 (some scopes have quirks).


Dobs (eg the xt8) don't always have enough in-travel to reach focus when you attach a camera. Some don't have enough out travel. You can fix the out travel problem with an extension tube, but there isn't always an easy fix for insufficient in-travel. The primary mirrors of some dobs have a lot of travel (via collimation screws) but not all do. Some people cut their truss tubes but I don't think one would do that to an xt8.


Obviously, no long exposures will be possible unless your friend has some kind of equatorial platform for his telescope.


Here is a picture (works the same for a dob... the thing just fits into the 2" focuser. In this case, the t adapter has been inserted into a 2" extension tube.).


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[steve_m]

You'll need one of these...


http://www.telescope.com/control/product/~category_id=photo_accessories/~pcategory=photo_accessories/~product_id=A0317


and one of these...


http://www.telescope.com/control/product/~category_id=photo_accessories/~product_id=05262

[steve_m]

Or, one of these. This one is a little less expensive.


http://www.telescope.com/control/product/~category_id=photo_accessories/~pcategory=photo_accessories/~product_id=A0321


These are from Orion and should work with your Orion Telescope.

[steve_m]

Or one of these.


http://www.telescope.com/control/product/~category_id=photo_accessories/~pcategory=photo_accessories/~product_id=A0310

[Jon Ruyle]

Or, one of these. This one is a little less expensive.

I'd be a little wary of 1 1/4" adapters... seems likely to cause vignetting, even with a 1.6fovcf ccd. Dunno for sure, though. And if the object is to take pictures of things with tiny angular size (like planets, excepting Earth, of course) then no problem anyway.

[Tony Printezis]

Hi all,


First many thanks for the very helpful answers! We didn't know that Orion actually had adapters, so we'll get in touch with them to get more information on whether the proposed adapters will work correctly on the XT8.

Obviously, no long exposures will be possible unless your friend has some kind of equatorial platform for his telescope.

That's right, his XT8 doesn't track. So, the question is: is it worth it? I'm sure that, even at ISO 1600, most faint stars will not be visible. On the other hand, close-ups of the moon should work out fine. Will we be able to take shots of any in-between subjects, like say Jupiter or Saturn? And what sort of exposures will we be limited to? 1/50sec? Faster?

seems likely to cause vignetting

I don't think this will be too much of a problem for dark sky shots!


Thanks again for the feedback and sorry for all the questions!


Tony

[Jon Ruyle]

That's right, his XT8 doesn't track. So, the question is: is it worth it? I'm sure that, even at ISO 1600, most faint stars will not be visible. On the other hand, close-ups of the moon should work out fine. Will we be able to take shots of any in-between subjects, like say Jupiter or Saturn? And what sort of exposures will we be limited to? 1/50sec? Faster?

I think the only possibilities are the moon, Jupiter, and Saturn. I've take pictures of the moon with a 12 1/2" f/5 dob and 2x barlow, which is almost three times the focal length of the XT8. I used 1/250 sec. Probably could have gotten away with longer, but I don't know exactly. It is likely that mount jiggle will be the limiting factor for shutter speed, not moving sky.


Which makes me wonder... will there be a balance issue with a heavy DSLR on a little xt8?


As to the question "is it worth it?", that depends on how much your friend wants to take pictures. I think it is worth a try, but it might not work (maybe you can't reach focus, or the thing will be impossible to balance, and there may be other unanticipated difficulties). Maybe the guys at the telescope store (astronomics, orion, or whoever) will have advice.

I don't think this will be too much of a problem for dark sky shots!

I don't think vignetting would be a problem for Jupiter or Saturn, but might be for the moon.

sorry for all the questions!

I don't think any one on this forum minds questions. At least I hope not- I've asked a million. []