When I first got interested in stargazing, I took a telescope making class from Brent Watson. In teaching us about the optic train Brent stressed how every piece of glass inserted in the light train has an effect on what we see and that we would be handicapping ourselves if we built a great mirror and then didnt get good quality eyepieces. In a short time of research on the web, right or wrong, it seemed apparent to me that the standard for comparison in many cases was the Tele Vue Nagler eyepieces. It seemed to me that most folks were looking for the same quality eyepiece but for a cheaper price as the Negalrs tend to be expensive. At the time I was using a 5 Meade that came with 0.96 no-named Japanese eyepieces that were cheapies in order to keep the price in line with Wal*Mart standards. I got a 1.25 adapter from Meade and my first real quality eyepiece was a 13mm type 6 Nagler. I will never forget the experience of my first view through the Nagler after having become used to the 0.96ers. In bringing the moon into sharp crisp focus I was immediately stunned with the image before me and all I could do for the longest time as my eye traveled across the detail of the moons surface was to say to myself, Wow! Wow! Wow! I have since joined the throng of those looking for the Wow experience for a cheaper price. In my pursuit I have heard some good things about many eyepieces like University Optic Orthoscopics, which I managed to pick up a few. I recently bought a 15mm (1.25) eyepiece form Seibert Optics (http://www.siebertoptics.com/SiebertOptics-1.25in-eyepieces-ultra.html#15mm) and I also bought a 15mm and a 19mm (both 2) from Russell Optics (http://www.citlink.net/~optics/products.html) that were very reasonably priced; on sale at the time for $60.00 a piece where as the Siebert was about $150.00 I then asked our own illustrious Chuck Hards if he would evaluate them, and he graciously accepted the challenge. Following is Chucks evaluation. Keep in mind Chuck is only commenting on his experience with these individual eyepieces. Smaller companies may tend to have a somewhat larger variation in the quality of their output than a big company like Tele Vue has. So if some of you have one of these other eyepieces and really like yours, you may have a good one. I dont know enough about either company to make a judgment as to whether these individual eyepieces are representative of the companies standard output or not. I do value Chuck's many years of experience and his perceptiveness in all areas pertaining to astronomy.
Chuck Hards wrote:
Hi Jim:
OK, here goes, while it's all still fresh in my mind.
I used the Orion 80mm ED scope, on the Weightless
mount. Both 50mm finder and a red-dot sight,
Williams Optics 2" diagonal.
TV Nagler 13mm type 6: Great imagery, no detectable
abberations out to the edge of the immense field.
Short eye relief, cannot see entire FOV with glasses
on. Magification is low with the little refractor
and this eyepiece, but it looks like my 12mm Konig is
just as sharp and maybe a bit sharper, at the expense
of half the FOV. But the Nagler is a "Cadillac" of
eyepieces and there's no denying it. Sweet.
[Chuck next looks a the Seibert ultra wide 15mm]
Silver Eyepiece (marked only "15 U") 1.25" OD:a
nice eyepiece, although not a particularly wide
apparent field. Well-corrected out to near the very edge,
fair eye-relief, the fold-down eyeguard is a boon to
eyeglass wearers and allows the entire FOV to be
taken-in with glasses on. Requires a lot of "in"
travel, I was worried I'd bottom-out on my secondary
mirror's surface and slid it into the diagonal
carefully. But this eyepiece performs well,
mechanics aside. I'd keep this one in my box if I didn't
have an obviously better one at the same focal length.
You can feel good about this purchase.
[Chuck now looks at the two Russell eyepieces]
15mm "Super-Wide" 2" OD: This eyepiece was
obviously not in the same class as the first two as soon as
I focused it. What appears to be strong coma is
probably severe astigmatism in this eyepiece. Stars
are stretched-out beginning only 1/2 way to the
edge of the field. The test for astigmatism is to watch
it change from a vertical slash to a horizontal
slash as you rack through best focus. In a comatic
condition stars would have "wings", flaring away
from the center of the field.
Eye-relief was too short to use with glasses and
even uncomfortable without them. But the distortion
alone makes this eyepiece a big loser.
19mm "Super-Wide" 2" OD: Same general complaints
as the 15mm, but to a much lesser degree: I could
almost live with this eyepiece, say on a large finder.
But not for any kind of critical viewing.
The 15 and 19 are Russells, aren't they? They just
go to show you that wide-field is no good if it's not
sharp too. Sell them on-line or at the next
swap-meet. Is the silver one a Siebert? That one's not bad at all.
Thanks again for letting me play with these, it was
fun and enlightening.
C.
--------------------------------- Do you Yahoo!? Yahoo! Mail - 50x more storage than other providers!