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Posts Made By: Arthur M. Schneiderman

April 2, 2002 05:38 PM Forum: Telescope Making

Jaeger 6" F/5

Posted By Arthur M. Schneiderman

I built a richest field telescope using this objective in the late 70s. The six spacers seem to be working their way toward the center of the doublet. Star images show three (vs. the 4 from spiders) rays that disappear if I mask the objective to ~5". Any suggestions as to someone who can refurbish this lens properly?

April 2, 2002 05:41 PM Forum: Birding Optics and Photos

Televid adapter?

Posted By Arthur M. Schneiderman

Is there an adapter that would allow the use of 1.25" eyepieces on this scope?

April 4, 2002 05:05 AM Forum: Off Topic Discussions

withdrawing ad after the fact?

Posted By Arthur M. Schneiderman

Herb:

I purchased an item recently and the item was not as advertised. The seller took it back and promptly refunded my money plus return shipping. Aside from the fact that it was not of the advertised size, I disagreed with his claim of "mint" condition. But seeing as there are no operational definitions of condition, one man's "mint" is another man's "fair-to-good", I put that in the realm of opinion. However, I scored the transaction 3-star to reflect my dissatisfaction with the error and condition discription.

The seller has readvertised the item and corrected the size error. It appears though that the original ad has disappeared along with my seller rating!! Does that mean that anyone who gets a less than perfect rating can simply withdraw the ad? if so, how meaningful are the ratings?

May 11, 2002 06:35 AM Forum: Deep Sky Observing

rating seeing

Posted By Arthur M. Schneiderman

I occasionally see quantitative ratings of the seeing conditions, e.g. 7.5. Is there a standard or is this just a subjective estimate? Can anyone point me to a site that explains this as well as measures of transparency?

May 23, 2002 06:52 AM Forum: Deep Sky Observing

Measuring doubles?

Posted By Arthur M. Schneiderman

How are you measuring spacing and PA on doubles? I can't find any filar micrometers on the web. Are you just eyeballing them?

October 21, 2002 01:28 PM Forum: Off Topic Discussions

Including photo in AstroMart ad

Posted By Arthur M. Schneiderman

How do I include a photo in an AstroMart ad? I can only find info on adding one after the ad is posted. How do I include it in the original ad?

May 30, 2003 06:34 AM Forum: Zeiss

APQ manual

Posted By Arthur M. Schneiderman

Was there an owner's manual for the APQs? If so, can anyone suggest where I might get a copy (preferably in English)?

Thanks

July 24, 2003 03:07 PM Forum: Zeiss

Wanted: Zeiss filar micrometer

Posted By Arthur M. Schneiderman

I'm looking for a Zeiss micrometer eyepiece (filar) with illuminator. Please give condition and asking price. Photos if possible.

Thanks,

Art

August 8, 2003 06:55 AM Forum: Eyepieces

microscope vs. telescope eyepieces

Posted By Arthur M. Schneiderman

There are lots of ads for high end microscope eyepieces with adapters for telescope use. Are there any fundamental differences in optical design criteria between them and comparable telescope eyepieces or is it just a packaging issue?

For example, is color correction, F/number, etc. equally important for both uses?

Bottom line: is a Zeiss 10X Abbe Ortho microscope eyepiece optically indistinguishable from a 25mm ZAO telescope eyepiece?

September 18, 2003 11:06 AM Forum: Zeiss

Identifying Zeiss microscope eyepieces?

Posted By Arthur M. Schneiderman

I hope this isn't too far off topic ... but: is there a source (online or hard copy) for identifying the various Zeiss microscope eyepieces? I know they usually have a six digit identifier, but is there any logic to those numbers?

For example, I have a Zeiss West Germany model 46 40 30 - 9901. It's also labeled "Plan W 10x/25" and has the eyeglass symbol. I assume that the "W" stands for widefield, the "10x/25" means 10x or 25mm focal length, and the eyeglass means that it has sufficient eyerelief to be used with eyeglasses. How can I find out more including its value?