TMB/APM Mono Eyepieces
Posted 07 September 2003 - 08:03 AM
" August 8/9, 2003; 11:50 PM - 2:50 AM EDT.
I pulled out 10mm, 6mm and 4mm of each. Turned the scope on Gassendi. 10mm Zeiss has larger FOV . Using the 10mm TMB I moved to the bright edge of the moon. No color. None. back to Gassendi. Back and forth using 10mm Zeiss and 10mm TMB. Other than the larger FOV with the Zeiss, NO difference. Then to the 6mm. Difference in FOV is minimal now...Back and forth. I am following rilles on the SE floor near M toward the central mountain complex. The detail is slightly better with the 6mm TMB, yes, definitely better than the Zeiss. O.K., subtle, but of the two the TMB gives the better view. 6mm = 304X. To the 4mm (457X). Seeing won't allow any more detail. I go back and forth between the two and see no difference. Any FOV difference is too small to be concerned about. I then turned to Mars. Oh my, what a view! I once again found the 6mm TMB to be a real gem. This time the increased FOV of the 10mm Zeiss made no difference. I then moved to the binoviewer and used the TMB super monos almost exclusively..."
Zeiss Abbe Orthos now sell for $600 to $700 each. For Lunar/Planetary observing, and, at $200 each, the TMB super monos are a deal in my opinion. The differences I observed between the TMB and Zeiss eyepieces were subtle but, if I concluded that the views using the TMB super monos and the Zeiss Anbbe orthos was the same that would be enough. I had no problems with eye relief as monoculars or in the binoviewer.
Posted 08 September 2003 - 12:33 AM
Posted 08 September 2003 - 12:18 PM
Posted 08 September 2003 - 02:28 PM
Thanks for the feed back on the comparison between the UO orthos and the TBM's. I have been most impressed with my 12.5mm ortho. While the TBM's seem to be a great eye piece, I can save my money with the UO's and spend the balance on a Panoptic. At some point I do want to take one for a test ride.
PS: Well written article! Enjoyed it very much.
Posted 08 September 2003 - 06:12 PM
That is why i was extremely interested in the test of the TMB versus the Radian (in this case: the 6 mm.)
That is also where your remark is troubling me, as you wrote:
"Despite the Radian being of a completely different design, it clearly belonged in the comparison. It was very sharp, as good as or maybe even better than the TMB and with a much more comfortable AFOV. But the mono's advantage in contrast gave it a slightly better image. "
Do i read well that it is slightly SHARPER, but looses very slightly on contrast??
So, i would be very interested in comparing a TMB 4mm to a similar Radian 4 or 3mm (i have a 3 mm Radian, and your test might suggest i better should stuck to my radian!)
Sharper image + parafocal + comfortable view + nice eyerelief for people wearing glasses + wider field of view thus suitable for planets and "general use", wow, that seems a lot in favor of the Radian?
Posted 09 September 2003 - 08:52 AM
Hard to disagree with your conclusion. The Radians do many things well, and are indeed designed to maximize sharpness. Thomas Back did a comparison of a 5mm Radian with his very fine 5mm Nikon ortho and found a similar result, which was that the Radian lost a bit in contrast but was just noticably sharper.
The TMB Super Monos are specialty eyepieces, and are designed to maximize contrast, light transmission and image sharpness within the limits of this particular eyepiece design. For many planetary observers who value these features exclusively, the TMB's will do the job very, very well. It was my experience that in the minor tradeoff between sharpness in the Radian and contrast in the TMB, better contrast gave a more satisfying image to my eye.
But as you rightly note, if you're looking for a more versatile eyepiece with better eye relief, greater AFOV, parfocal, etc. (and don't mind a bit of color at the edge of the field), the Radians are hard to beat.
Posted 09 September 2003 - 09:20 AM
Some time ago on Cloudy Nights, I compared a 9mm Pentax ortho with a 9mm UO ortho. The UO ortho came out surprisingly well in the comparison. One point I made in that review was that it would be a shame to spend money on a few pieces of high end equipment that would keep you from buying other equipment (such as a Panoptic!) you'd enjoy using. I agree with you both that UO orthos are great eyepieces with excellent effective eye relief, and I think they're among the best values available in our hobby.
And thanks for your kind comments on my review, Ron!
Posted 09 September 2003 - 11:59 AM
That was a very well written article. Whether or not the product is right for me, I enjoy when I read an article that exhibits method, structure and fair conclusion.
Posted 10 September 2003 - 08:35 AM
Posted 11 September 2003 - 08:34 AM
Thank you! It was fun to write...