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Posts Made By: George Kiger

April 28, 2005 12:14 PM Forum: Home Observatories

Privat APM Backyard Roll Off Observatory

Posted By George Kiger

Any fear of roof failure in heavy weather - snow, ice, strong winds?

May 13, 2005 09:41 AM Forum: Refractors

3 Apo vs. 4 Acro

Posted By George Kiger

Jeff Thomas said:

Just a quick poll. Given equal quality and prices and assuming a mix of deep sky and planetary observing, would you prefer a 3 inch APO or a 4 inch acromat?

What sources have been found for 4-inch achromats in the f/12 to f/20 range - and what is your take on the quality of the lenses?

September 22, 2005 04:01 PM Forum: CCD Imaging and Processing/Solar System

Mars Image Comparo - C9.25 vs. 6" apo refractor

Posted By George Kiger

It appears that the C9.25 has a bit more detail around the edges of the dark areas.

Too bad you already have a C9.25 - I was going to trade mine to you for the FS152 (as a favor to you, of course).

November 29, 2005 02:09 PM Forum: Eyepieces

Minimum exit pupil????

Posted By George Kiger

Michael Koons said:What is the minimum recommended exit pupil? I've read a bunch and have seen cited .5mm. Is that it? Thanks!!!!!!Mike

That's 51x per inch. One of my old books says no more resolution past 60x per inch, or about 0.4mm exit pupil. My own experience in observing says that past 60x per inch there is no additional visible detail.

I am sure that you have heard of scopes where the image does not break down at 100x per inch, but I've never heard it addtionally reported that more fine detail was visible at those magnifications.

February 10, 2006 09:56 AM Forum: Telescope Making

Converting an f/8 to an f/16

Posted By George Kiger

Another problem with this approach is that the 'first diagonal' would have to be very large - your obstruction would likely be over 50%.

April 5, 2006 10:51 AM Forum: Telescope Making

Is this wild idea possible? (bi-refractor)

Posted By George Kiger

Stu Lieberman said:

A really wild idea:

Use 2 star diagonals and 2 flat mirrors.

Have the scopes pointing left and right horizontal each looking at a 45 degree mirror to the sky. Like a binocular mirror.

To adjust IPD, move the scopes in or out horizontally.

It would look like this:

()====== = /= ======()/


No question that it would work - but WHY?

May 23, 2006 02:59 PM Forum: Equipment Talk

Restoration complete!

Posted By George Kiger

Floyd, now that the scope is finished you'll have time to cut the grass. smile

Just kidding - that's a beauty of a scope. Congratulations.

September 7, 2006 11:31 AM Forum: Eyepieces

Long fl orthos

Posted By George Kiger

I don't think optical issues are the reason.

The ortho's strength is a well corrected field, while its weakness is medium-to-narrow field. For low powers the highly corrected field is somewhat wasted, and most people prefer wider apparent fields for their low power eyepieces.

September 28, 2006 07:50 AM Forum: Eyepieces

TMB 40mm Paragon

Posted By George Kiger

Wouldn't most of the edge performance and field curvature issues you are seeing come from the normal issues with fast Newtonians?

October 2, 2006 09:45 AM Forum: Eyepieces

5mm EP Review by William Paolini

Posted By George Kiger

This is one of the best reviews I have ever read. And it was done with three very different eyepieces which makes it even more challenging.

I was going to quibble with doing a high-power eyepiece review when the seeing was only 5, but we don't always wait for an 8+ night, do we!

Great job.