Re: Get Me Started (again...)

Stephen Paul wrote:

Something else that you should be aware of is that Dobsonians are generally designed for visual use and the higher end models especially tend to come with low profile focusers designed for eyepiece use. These do not have the correct focal plane position for a camera. In order to do imaging with one of these on a platform drive, you will need to push the focal plane further out of the focuser by either shortening the poles on a Truss design, or pushing the mirror forward in a solid tube design. 

Not a problem, especially with the xt10. Drill 3 holes and you're done.


The other issue with a Dobsonian is that it puts the eyepiece further from the ground than does an SCT, refractor, or Mak of the same aperture. For children this is especially difficult as you will need some means to get them up to the eyepiece of larger apertures (with their longer focal length).

I don't think so. Use a step ladder and there will be no problem at all. Besides, depending on the tripod the eyepiece for an LX90 might still be too high for a little one.


The ideal scope for visual use as it concerns the mount, is something like the Meade LX-90. This is a GoTo fork mount that operates in altazimuth mode (as do all the GoTo fork mounts). These keep the eyepiece in a very tight range of positions. The most uncomfortable position being straight up if your seat height is too high, and on the horizon if your seat height is too low (or tripod too far extended). I am personally interested in one of these as they are also ideal for use with a binoviewer. The reason becomes obvious once you see how the altazimuth fork mounts operate.

I just don't agree with you here (and that's unusual for me). If his limiting budget is 1200 bucks, and portability is no concern, he'll be dumping a bunch of money on three extra optical surfaces by buying an SCT. Plus, the central obstruction will significantly affect contrast. I have an SCT and a dob. The views through the dob are simply better. He lives in a dark place. Give him as much aperture as possible and digital setting circles. He might never need to get a larger scope than a 10 inch. Put it onto an eq platform (which you can make if you have the time and inclination), he'll be able to do some basic photography. Certainly webcam stuff and maybe even some long exposures. And he'll be able to decide if he's really all that interested in imaging. If he is, you and I both know that he'll not be satisfied with the LX90, and he'll still be tossing out a ton of money on a Losmandy or similar, and he'll probably want more aperture, too. I'd never seen the intelliscope before, and for the money, I doubt it can be beat. That's quite a nice little scope for $700.

just my .02.

Chris
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