Telescope Reviews: Nagler vs BO for planetary viewing?

To me, the issue of eye relief is kinda-sorta a tradeoff.

Most of the more specialized types (Orthos, Plossls, Monocentric) have FAR more issues with eye relief than the 5mm and 7mm Naglers (I own both..).

For my own use, I have come to greatly respect the T6 Naglers in the 7mm and 5mm focal length for some viewing.

For example, when I put Jupiter in the field of my 6" refractor, not only is Jupiter stunning, but ALL OF THE MOONS are perfect little spheres!. In most of the other eyepieces I used (including a BO/TMB which was not very sharp off axis) I couldn't even get the moons IN to the field.

I have done extesive testing on a variety of targets (Outdoor and indoor test targets, which I think are more "Objective" than testing on planets under varying seeing) and even barlowed, the Naglers are almost indistingusable from just about any other eyepiece made. The difference in sharpness and contrast is almost impossible to see.

Of course in some scopes, the wider field of the Naglers may not be a astetically pleasing because many faster scopes start to show a lot of coma off axis. The Nagler can't fix this, so for someone that is bothered by it, maybe a conventional field is more desirable to cut off the outer abberations.

I do think the Radians are excellent eyepieces however. I owned several over the years. They are both comfortable and BRILLLIANTLY sharp at the edge of the field. In my 6" scope, I could litterally split any double at the edge of the field that could be split at the center of the field. You could set the Airy pattern RIGHT on the edge of the field and literally split the Airy disk with the Field Stop!

But at the end of the day, I don't think the Radian was any sharper on-axis than the Nagler is, and the Nagler is a FAR more practical eyepiece because at high powers in general observing is when you need the extra true field the MOST!

And I look at EVERYTHING at High Powers! I use "Planetary Powers" to look at EVERTHING. Even if it doesn't fit in the field, I STILL study it at high powers. And when you DO that, you see extra detail that doesn't show up at lower powers.. And when you realize that, Naglers suddenly look like the best game in town...

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Celestron C14, CGE (Big Al)
Astro-Physics 6" f/8 (Buffy)
Televue 101 (No name, but I call it my Widescreen HD Space TV)

The night sky is my mistress. She seduces me away from all other lovers.