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Eyepiece Light Transmission

Started by wpaolini, 07/11/2006 09:02AM
Posted 07/11/2006 09:02AM Opening Post
FYI, in case not yet discovered, just found this interesting test of light throughput from a large variety of eyepieces. Slides 22-28 show all the results. Thought this forum might be interested.

Interesting how the UO Orthos were quite high as a group and that the Naglers fell only slightly behind even though significantly more glass. Also interesting how much different throughput between the differing TV designs. Pans showing much less than Naglers, particularly between the 22mms in those 2 designs. The absolute winners were a Tele-Optics 40mm Keller and the Siebert 27mm Erfle (presume it's his 26mm Performance series) which both topped over 98%!!


Posted 07/11/2006 10:22AM #1
Siebert's eyepieces are still one of the best kept secrets of the astronomy world. I have the 24mm 3 element 65 degree Ultra and it is the sharpest and brightest eyepiece in my collection...which includes some Nagler and Pentax high priced spread types.
It is also very lightweight which makes it a great bino eyepiece. Incidentally, on his website his ad refers to the 24mm as "high transmission"....which I believe is pretty accurate.
Posted 07/11/2006 01:57PM #2
Very interesting page with a lot of data.
Not sure how much accuracy you would get with such a test, but it is a definitive test with repeatable results and standards, so I like it. smile
Looked to me as if there were clear winners as to throughput, but that is to be expected with EPs with only 3 eliments compared to perhaps 7-8. It is actually amazing that there was so little difference between the simple and complex EPs. :S
Also, they did not test all of certain designs like the Radian for instance, only the 4mm. Too bad, I would have liked to see the entire series results. I find that at the eye, I can not see any real difference between the 5mm Radian and the 5mm UO HD FMC Ortho. I guess that 2-3% is just not enough to register at the eye, or so I have read.
But a good effort by them to figure out the throughput issue.

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