My favorite 1st scope recommendation is back

Started by macdonjh, 11/12/2013 05:05AM
Posted 11/12/2013 05:05AM Opening Post
If you're one of those beginning astronomers that is looking to purchase his first scope, my favorite recommendation is now available again. Thanks to Orion for reintroducing the 6" XTi. You can read my review here. I think it's an outstanding value. If you decide to purchase one, please also purchase a laser collimator (the least expensive available will do) at the same time. Keeping it collimated is essential, but also easy once you've practiced.
Posted 11/12/2013 01:32PM #1
Once again the 6-inch aperture RULES for an ultimate, but wise, 1st-time telescope! My first REAL telescope was indeed a 6-inch...6-inch f/8 Edmund mirror in a homemade tube full of duct tape, Krylon spray paint, and plumbing clamps. I called it THE HUNTER back in my teen years.

All the best

Just a few thoughts:

8) FS-152SV sitting in the office
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:S Meade ETX-90 finder scope position
shocked Hino Optical Mizar 120SL observatory model
:C SR-4mm eyepiece with a 3x barlow in a 60mm refractor
8O Zeiss Victory 7x42 SFs
wink Having over 135 vintage oculars to play with
smile My life surrounded by wonderful friends and impeccable optics
Posted 11/13/2013 12:52PM #2
John MacDonough said:

If you're one of those beginning astronomers that is looking to purchase his first scope, my favorite recommendation is now available again. Thanks to Orion for reintroducing the 6" XTi. You can read my review here. I think it's an outstanding value. If you decide to purchase one, please also purchase a laser collimator (the least expensive available will do) at the same time. Keeping it collimated is essential, but also easy once you've practiced.

A few thoughts:

6 inch F/8 certainly a nice scope, I have owned a few, a couple of RV-6s, some Dobs. I am sure you will enjoy yours. However, these days, I have to believe an 8 inch F/6 dob is a better first serious scope. A few reasons:

- There is not much difference in size between a 6 inch F/8 and an 8 inch F/6, the OTA is a little bigger around but essentially the same length. For both scopes, the heaviest pieces is about 20 lbs.

- 8 inch versus 6 inches, this represents a significant increase in capability, globular clusters begin to resolve, galaxies are more easily seen, clusters are brighter, the planets are more detailed an brighter.. the difference is about 33% in resolution, 78% in light gathering, this is significant.

- 1.25 versus 2 inch focuser. The Orion XT-6 scopes come with a so-so 1.25 inch rack and pinion focuser. Stock they are generally tight and sloppy. With some work, they can be pretty nice but still not great. They also represent a significant limitation on the field of view, a wide field of view is an advantage for a beginner, particularly one interested in Star hopping. The 8 inch Dobs come with decent quality 2 inch Crayford focusers, the GSOs come with quite nice 2 speed units. Buying a decent Crayford and adapting it to the XT-6 puts the overall cost right there with an 8 inch Dob...

My thinking:

If the Intelliscope feature is important, Orion really has the only game in town. The XT-6i does represent a savings over the XT-8i. But if Goto is not on desired, then the 8 inch GSO dobs from Apertura, Zhumell, Astro-Tech and others represent a better value, the 2 speed focuser, a 2 inch 30mm widefield as well as a 9mm plossl, a laser collimator.. $400 buys you an 8 inch GSO shipped to your door.. cheaper than a 6 inch intelliscope by about $80.

If one is interested in a 6 inch F/8 Dob without Pushto, then the Bushnell Ares 6 is looks to be the best value. Manufactured by Synta who also manufactures the Orion Dobs, it has a 2 inch focuser and some nice accessories. It's also only $280.

- Laser collimators: a good one (Howie Glatter) with some sort of Barlowed laser, is a very good way to collimate a Newtonian.

However, the inexpensive lasers are best avoided. There are a number of reasons for this. First they rarely arrive collimated, I have seen quite a few of them, I have never seen one that was properly collimated so that when the collimator was rotated in the focuser, it did not scribe out a circle. They can be user collimated but they do not stay in collimation for long. The fit in the focuser is sloppy..

There are other, affordable, reliable collimation tools, the collimation cap shares many of the positive features of the Barlowed Laser for adjusting the primary mirror tilt, a Cheshire or Combination tool is useful for setting the secondary tilt.

My two cents...

Jon