When gear heads by eyepieces

On Wednesday, 20 May 2015 11:59:00 UTC-4, palsing wrote:
On Wednesday, May 20, 2015 at 3:51:20 AM UTC-7, wrote:
On Wednesday, May 20, 2015 at 12:23:52 AM UTC-4, palsing wrote:

Whatever, these guys are terrific planetary eyepieces...

Are you damning them with faint praise?

Not at all, these guys are highly regarded by many folks who like to observe the planets, planetary nebulae or double stars, especially at high powers, even though they have a very restricted 32-degree field-of-view when compared to most modern eyepieces. See this...

http://www.cloudynights.com/documents/tmb.pdf

... and check out the chart on the last 2 pages... and this review...

http://ejamison.net/equipment_reviews3.html

... and there are many others to be found, too.

So fantastic...they stopped making them due to lack of demand. But, if anyone is interested and you know a good machinist, you can always have barrels made and buy 10/20 scratch/dig triplet lenses from a good supplier and get something similar to the monocentrics.

On Wednesday, 20 May 2015 22:25:03 UTC-4, wrote:
On Wednesday, May 20, 2015 at 5:26:49 PM UTC-4, Quadibloc wrote:
On Wednesday, May 20, 2015 at 4:49:24 AM UTC-6, wrote:
On Tuesday, May 19, 2015 at 11:45:14 PM UTC-4, RichA wrote:

2. TMB Supermonocentrics 10mm and 16mm
Both are in pristine condition. Come with original boxes. The 10mm was
bought
new from APM just last month and was never used - only been out of box
twice
for picture sessions.

There was a hilarious review of these in S&T, August 2004. (Those with poor
reading skills might not grasp the humor.)

Come to think of it, there _is_ one potentially funny thing about a monocentric
eyepiece.

Although it would be funnier if it were made of quartz instead of glass...

But the adjustments to your equatorial drive might be awkward...

http://www.cloudynights.com/topic/47...lens-eyepiece/

It works!

On Wednesday, May 20, 2015 at 11:59:00 AM UTC-4, palsing wrote:
On Wednesday, May 20, 2015 at 3:51:20 AM UTC-7, wsne... wrote:
On Wednesday, May 20, 2015 at 12:23:52 AM UTC-4, palsing wrote:

Whatever, these guys are terrific planetary eyepieces...

Are you damning them with faint praise?

Not at all, these guys are highly regarded by many folks who like to observe
the planets, planetary nebulae or double stars, especially at high powers,
even though they have a very restricted 32-degree field-of-view when compared
to most modern eyepieces. See this...

http://www.cloudynights.com/documents/tmb.pdf

... and check out the chart on the last 2 pages... and this review...

http://ejamison.net/equipment_reviews3.html

... and there are many others to be found, too.

As was I reading the S&T article I did a quick cost/benefit analysis and concluded that a larger scope with ordinary Plossls would be a better use of funds. YMMV.

On Thursday, May 21, 2015 at 3:11:47 AM UTC-4, RichA wrote:
On Wednesday, 20 May 2015 02:10:23 UTC-4, Chris.B wrote:
On Wednesday, 20 May 2015 05:45:14 UTC+2, RichA wrote:
They don't look though them, they take the out for "photo sessions!" La la la, la!!!

"Astromart:

2. TMB Supermonocentrics 10mm and 16mm
Both are in pristine condition. Come with original boxes. The 10mm was bought new from APM just last month and was never used - only been out of box twice for picture sessions."

Man has been BUYing and selling pretty rocks since long before you discovered Fox News.

Why pick on somebody who BUYs and then sells some eyepieces?

Psst. Anyone wanna BUY some really dirty eyepieces? ;-)

Because the rock serves no other function except to look pretty? Maybe a paper-weight.

LsD will probably drop in soon and weigh in.

On Thursday, May 21, 2015 at 12:13:28 AM UTC-7, RichA wrote:
On Wednesday, 20 May 2015 11:59:00 UTC-4, palsing wrote:
On Wednesday, May 20, 2015 at 3:51:20 AM UTC-7, wrote:
On Wednesday, May 20, 2015 at 12:23:52 AM UTC-4, palsing wrote:

Whatever, these guys are terrific planetary eyepieces...

Are you damning them with faint praise?

Not at all, these guys are highly regarded by many folks who like to observe the planets, planetary nebulae or double stars, especially at high powers, even though they have a very restricted 32-degree field-of-view when compared to most modern eyepieces. See this...

http://www.cloudynights.com/documents/tmb.pdf

... and check out the chart on the last 2 pages... and this review...

http://ejamison.net/equipment_reviews3.html

... and there are many others to be found, too.

So fantastic...they stopped making them due to lack of demand. But, if anyone is interested and you know a good machinist, you can always have barrels made and buy 10/20 scratch/dig triplet lenses from a good supplier and get something similar to the monocentrics.

I believe the main reason they stopped was because the designer and manufacturer, Thomas M Back, passed away suddenly in 2007. Keep in mind also that these are very specialized eyepieces and not very popular with the general amateur observing population, due to their very narrow field of view. Still, there are a lot of experienced observers who swear by them for high magnification views of small and dim objects, as they pass more light than just about any other eyepiece design.

\Paul A

On Thursday, 21 May 2015 13:05:25 UTC-4, palsing wrote:
On Thursday, May 21, 2015 at 12:13:28 AM UTC-7, RichA wrote:
On Wednesday, 20 May 2015 11:59:00 UTC-4, palsing wrote:
On Wednesday, May 20, 2015 at 3:51:20 AM UTC-7, wrote:
On Wednesday, May 20, 2015 at 12:23:52 AM UTC-4, palsing wrote:

Whatever, these guys are terrific planetary eyepieces...

Are you damning them with faint praise?

Not at all, these guys are highly regarded by many folks who like to observe the planets, planetary nebulae or double stars, especially at high powers, even though they have a very restricted 32-degree field-of-view when compared to most modern eyepieces. See this...

http://www.cloudynights.com/documents/tmb.pdf

... and check out the chart on the last 2 pages... and this review...

http://ejamison.net/equipment_reviews3.html

... and there are many others to be found, too.

So fantastic...they stopped making them due to lack of demand. But, if anyone is interested and you know a good machinist, you can always have barrels made and buy 10/20 scratch/dig triplet lenses from a good supplier and get something similar to the monocentrics.

I believe the main reason they stopped was because the designer and manufacturer, Thomas M Back, passed away suddenly in 2007. Keep in mind also that these are very specialized eyepieces and not very popular with the general amateur observing population, due to their very narrow field of view. Still, there are a lot of experienced observers who swear by them for high magnification views of small and dim objects, as they pass more light than just about any other eyepiece design.

\Paul A

I guess he took the designs to the grave.

On Thursday, May 21, 2015 at 1:05:25 PM UTC-4, palsing wrote:
On Thursday, May 21, 2015 at 12:13:28 AM UTC-7, RichA wrote:

So fantastic...they stopped making them due to lack of demand. But, if anyone is interested and you know a good machinist, you can always have barrels made and buy 10/20 scratch/dig triplet lenses from a good supplier and get something similar to the monocentrics.

I believe the main reason they stopped was because the designer and manufacturer, Thomas M Back, passed away suddenly in 2007.

http://www.burgessoptical.com/words-...omas-back.html

On Thursday, May 21, 2015 at 7:41:26 PM UTC-5, RichA wrote:


I guess he took the designs to the grave.

Monocentric design is quite simple, not complicated like more modern eyepieces. Basically it's a cemented triplet, the glass type and curves are well known to any optical designer. It is not too difficult to produce in the longer focal lengths, 10mm and longer. The tricky part is making very short ones, since the lens diameters get extremely small. It is not easy to align and cement a 2mm diameter lens set, basically the size of a grain of sand. I have personally assembled several hundred similar sized triplet oculars in the past, and can attest to the difficulty involved.

On Friday, May 22, 2015 at 12:41:49 PM UTC-4, Uncarollo2 wrote:
On Thursday, May 21, 2015 at 7:41:26 PM UTC-5, RichA wrote:

I guess he took the designs to the grave.

Monocentric design is quite simple, ...blah, blah, blah

I think RichA was being facetious.

wrote:
On Friday, May 22, 2015 at 12:41:49 PM UTC-4, Uncarollo2 wrote:
On Thursday, May 21, 2015 at 7:41:26 PM UTC-5, RichA wrote:

I guess he took the designs to the grave.

Monocentric design is quite simple, ...blah, blah, blah

I think RichA was being facetious.

How can one tell?