Posts Made By: John Holt

I have a 25mm wide field (76x)that works good as a finder. I would like to get close to double that power for the next step.


Barlow?

Also, the Siebert Ultras are much better than the Standards. Had you thought about one of his 13mm? He has a petty generous return policy.

Why is it that after nearly 400 years refractors still cost more per in than any other scope.



Cause refractors are icky, and who needs one.

Actually they're not really inferior optically at all. Just not for fast focal ratios. Nor eyeglasses. Just wide field, and light weight as you said.

Walter Schmitt said:

This scope does not readily accept 2" diagonal and eyepieces.
How can I improve its deep-sky, wide-field performance over stock?

This past weekend I spent some hours in the virgo cluster with an 8" out under dark sky, down a two track out in a meadow on public land. An 8" f/5 newt on an altaz mount. Most of the time at 90x or more with, 65 degree eps and Uranometria. I was able to pretty much just skip using my lowest power eps because of having detailed charting. I know that may not be a wide field answer for you, but detailed charting plus a portable scope really works well on deep sky. The Nexstar 8's that I have seen are pretty darn nice... and portable.

My vote is for something like a high end 12" dob also.
Just because my 13" non-high end dob has more miles on it then all my other scopes combined, by a considerable margin.

Perhaps this? Recently up again.
http://www.ngcicproject.org/

When prisons are closed due to lack of funds, inmates are going to be released. Sure, there will be criteria used for which ones. But some early release is a given.

john mclaughlin said:

Hi everyone,

Got a question for you all.

I bought a little 6 inch SN to try on my Stellarvue Alt/AZ mount. It was pretty cheap in cost, couldn't pass it up. I noticed when it is front heavy(meaning the back end is sticking out more from eyepieces and finderscopes) that the eyepiece height doesn't change all that much when going from horizontal to vertical. This makes it extremely comfortable and very easy to use. I can scan up and down with hardly moving in my chair.

My question is, does anybody have this in a bigger scope, like a 10 or 12 inch? If so, how does it work for you? Do you use counterweights to make it front heavy? Have you made a strong mount to hold it? Or does the eyepiece height change a whole lot to make it not worth it.

Thanks a bunch,

John

I have a short 6" mounted altaz too. You're right, the ep position moves in a pretty small arc, making it very easy to observe with. I use an 8" on the same mount as the six, but it is not really stable enough. The 8 is f5 too, but twice the weight, longer and centered farther from the center of rotation. So lots of rotational vibration in 8" combo which is a work in process. The 8 also has the benefit of a relatively small ep position arc. The mount is homemade fold up whatnot of adjustable height that will fit behind a seat in the car. I like to stand more often than sit.

For a 10 or 12" one might have to think about a pier mount, with a single beam open type ota, with a secondary cage at the top and a counterweight up the beam beyond that.
Or much taller more traditional dobsonian mount, with as open a truss system as possible with large altitude bearings up the ota as far as possible and spring type virtual counterweights.

Somebody marketed a newt a few years back with the focuser in the altitude bearing sorta. I believe is was an 8" with a very tall pier type mount. I don't recall the brand name.

Good grief!

Harry Siebert makes 18mm's too, in his ultra line.
http://www.siebertoptics.com/SiebertOptics-1.25in-eyepieces-ultra.html