Jump to content

  •  

- - - - -

Discovery 6" EQ


Discuss this article in our forums

I’ve been an on/off observer for about 40 years. Currently I do my observing in the Southwest. Over the years I’ve owned mostly Newtonians, from 6” to 10” models. For nearly 20 years I used an 8” Dobsonian as my primary instrument.

Recently I’ve decided to scale down in favor of portability. For my primary instrument I choose the Discovery 6” EQ. From discussions with the Discovery staff, I learned that the 6” and 8” Eqs use the same mount. I opted for the 6” in favor of a lighter instrument, and figured the mount should be all the more stable for the choice.

The instrument arrived well packed, and was easy to assemble. It consists of a metal tube, with 6x30 finder and a solid rack and pinion focuser. The polar mount is as I’d hoped, very solid for this size instrument. It also has a built in polar alignment scope.
The only thing I was less than happy about is that the instrument has a 3-vane spider instead of a 4 vane (which gives 6 diffraction spikes), and the vanes are of a cast plastic, and quite thick, perhaps a quarter inch.

I was out observing the first night. At f/5, I didn’t expect the instrument to be a killer on planets, and that’s about what I saw. Performance on Jupiter was little better than a premium 2” refractor I have. But on star objects, like the double cluster in Perseus, it was outstanding.

The telescope came with 25mm and 10mm Plossls, which perform well. I noticed that in comparison, my old trusty Orthoscopic had quite a bit of glare I hadn’t noticed before.

After a few more trials, I notice that with all of my shorter focus eyepieces, the eyepiece tube extended well down into the light path. I determined the worst case, and what adjustment would be needed to have this eyepiece result in a an eyepiece tube extension that stopped short of the light path. Then I (after warranty was up) removed the optics and cut off the primary end of the tube by about one and a quarter inches, then replaced the optics. This was necessary in that the primary mount fastens to the end of the tube and acts as an endcap, so the only way to move the primary forward was to cut off the end of the main tube.

This necessitated re-installation of the optics and a thorough alignment. Now I find performance to be excellent for all type of observing. Saturn makes a beautiful object, the Cassini division easily visible, and the equatorial band around the planet stands out clearly. On good nights, Jupiter’s red spot is quite observable (appearing a pinkish tan on the last occasion), as well as are transits of Jupiters 4 large moons.

In summary, while mechanical construction of the telescope itself could have been better so there was no extension of the eyepiece tube into the light path, I find the instrument to be very good. There appears to be nothing cheezy about the instrument. The mount is very solid and smooth, and the optics, once I solved the eyepiece tube problem, perform flawlessly.




0 Comments



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics