Excelsis - Display Vote

TeleVue Radian 8mm

I had a chance to use an 8mm Radian on a 20" f/5 Obsession the other night. In isolation, it's a very nice eyepiece--sharp across the field, excellent contrast, and a nice wide field of view. Where it falls down, unfortunately, is when it's compared against the Pentax XL.

Relative to the Pentax XL, the Radian has more lateral color, perhaps slightly less contrast, a narrower field, and much more critical eye positioning. The Radian blacks out unless your eye is dead center, whereas the Pentax makes it much easier to get and hold the exit pupil. On that basis, giving the Pentax XL a 10 optically, the Radian deserves an 8. Other than for use in a binoviewer, I can't see any reason to choose a Radian rather than a Pentax XL.

As far as value, the $218 Pentax XL beats the $240 Radian in every respect except for size and weight, which makes it difficult to assign a very high number for value to the Radian. I gave the Radian a 4 for value, but that's kind of arbitrary. For many people, it would deserve a 0 relative to the Pentax XL. Why pay more for an eyepiece that's at best a step behind the Pentax? For others, like those who want to use a binoviewer or have balance problems, the Pentax XL might not be an option and the Radian would therefore deserve a much higher value rating.

Overall, I'll give the Radian a 6. If the Pentax XL didn't exist, the Radian would definitely deserve a 9 or a 10, but the Pentax XL does exist, which puts the Radian in second place.

Overall Rating: 6
Optics:8 Value:4
Weight: 10 (Trustworthy Vote)
Date: 02/18/2002 10:02:15 pm PST
By: Thompson
Link to this vote: http://excelsis.com/1.0/displayvote.php?voteid=68641

That's right this is about Radians not Naglers which are indeed revolutionary. It is a valid point that the XL beats the Radian. Now both have a challenger in the TMB/BO Planetary. LP kills digital!

Reply...  (again)... This review is about the Radian, not about Pentax eyepieces....  There are a select group of TeleVue haters out there.... Stick to your Pentax.... Anyone with a brain in their head knows that TeleVue is revolutionary in its approach to optics...  People are turned off by the expense, but once you look through an Al Nagler product you're hooked.  The Nagler 9 was my first and it is NOT matched by ANY other design I've ever tried in that focal length..bar none.
Including ORTHOS... This reminds me of audio freaks sticking to LP....Face it.... Digital beat the Analog Star !!

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