Posts Made By: John Wilson

About a 1 - 2 years ago, Markus Ludes of APM put a funny ad spoof on Astromart. I don't remember the details- He advertised it as something like the world's best telescope but it was clear from the picture that it was designed by a committee and assembled from spare parts. I think the mount was made out of a coathanger?? To find it, you'd have to do some fancy looking through the archives but it was quite enjoyable.

Markus, if you're reading this, do remember the ad I'm talking about? Anyone else know the ad I'm remembering?

Your quest sound like a good one. I hope your audience(s) like(s) the result.

Best wishes,
John

Thanks, Markus, for this good news!

For those of us who have been waiting for the new Pentax ortho eyepieces, do you know what focal lengths will be available?

Hi Charles.

I recently sent my 90S mount to Texas Nautical for repair (the DEC axis wasn't turning smoothly) and was pleased with the job they did.

Good luck with your mount,
John

Hi Brian.

You might try speaking with Don Yeier at VernonScope as I believe he still has at least some of the original Brandon drawings and specs. Also, I believe Gary Hand at Hands On Optics also knows a lot about the earlier Brandon equipment. They might be able to tell you some characteristics of the design (like whether the Brandon objectives had such a large gap) and how well it worked.

Best,
John

Hi Todd.

In the past, I've done an experiment similar in spirit to the suggestion to look at the side of a building, though I don't know whether your scope and circumstances would allow it. If you can focus on a yardstick (or tape measure?) that extends all the way across your field of view, you can note the width of your field "in inches" (or cm) with and without a barlow. The 2x barlow should decrease the field width by roughly a factor of 2 and the 3x by roughly a factor of 3. If you try this experiment and find that the 2x and 3x barlows are decreasing your field width by the same amount, one of them is lying about its magnification and you should be able to tell which one.

Hope this helps,
John

Hi Walter.

I also have a 2nd pair of glasses. My first pair, the one I wear "around" and to work, has trifocals for close, computer, and far vision. The central correction for the computer work *really* gets in the way of observing at the eyepiece. The second pair, which I use only for astronomy, has bifocals for star atlas reading and "distance" correction that I use for observing. This system works quite well for me and, if you find a convenient way to pack your 2nd pair (with your eyepieces, say), it doesn't require much extra effort. The downside, of course, is that it's expensive to get the 2nd pair of glasses.

By the way, I often take the 2nd pair on trips as a spare in case something happens to my primary pair.

I've discussed contacts with my eye doc but haven't gone that route... For what I do all day, I'd have to wear glasses over and above the contacts and it seems pointless to use both kinds of eye gear.

Hope the hymns pick up the spirits. If not, try the other way.

John

Hi Kirk.

I have some of the same issues you've mentioned, including a need for wearing glasses and finding may eyepieces shy on eye relief. Just a couple of thoughts-

I've never tried a field reducer so I don't know how that would affect your visual observing. Also, I tried a 32mm Meade Super Plossl once and found that I couldn't use it with glasses (couldn't even come close, in fact...). With glasses, I *can* use the TVO 32mm Plossl and the Celestron 30mm and 35mm Ultimas. The pre-eyecup (older version) 32mm, 24mm, and 16mm Brandons also have good enough eye relief that you can see the entire field with glasses. The Brandons with eyecups do not have this eye relief.

I've recently started using "classic", 4-element orthos with a 2x barlow and extension tubes. I happen to be using UO eyepieces but there are Kasai and "Circle T" equivalents. With my particular barlow, the extension tubes I have give me magnification factors of 2.4x and 2.7x. The 2.7x combination, for example, makes the 18mm ortho the equivalent of a 6.7mm eyepiece. Adding a 12.5mm ep would obviously give higher magnifications. Purists would argue that a barlow degrades an image slightly and that longer extensions increase aberrations but I've never had a real problem with this setup. Anyway, with your scopes, you could probably get a range of useful magnifications with, say, a 25mm and 18mm ortho with a 2x barlow and sundry extension tubes. These eyepieces are relatively inexpensive, lightweight, and quite forgiving in terms of eye relief. For my eyes and in my scopes, they give very sharp, high-contrast images. They're not wide field eyepieces but if you can be happy with 40 - 45 degrees, they can do a nice job.

Best,
John

(nm)

Hi James.

I'd second John's suggestion, although my stragegy has been a little different. I use an 18mm ortho (The UO model has good eye relief for glasses, at least for my glasses.) With that eyepiece, I use a 2x barlow to get the equivalent of a 9mm. On top of the barlow, I use 1" and 1.6" extension tubes to get the equivalent of 7.5mm and 6.7mm focal lengths. If you decide to go with the Klee, it's a good barlow and, coupled with the 18mm ortho (or maybe even a 25mm ortho?), would get you effective magnification in the range you're looking for and give you good eye relief. You might find either approach satisfactory.

Good luck,
John