Thursday, February 28, 2008

modern eyepiece

I went eyepiece shopping today!

I wanted a wider field and/or lower power than what I have now. The old 26mm Plössl by Celestron, which I believe has a 52° field of view, offers me 77 power and a final field of 0.68°. That shows the Moon with a bit of a border. But it truncates the Double Cluster in Perseus and M45...

I first visited Efstonscience. This is where I bought my SCT telescope, so there's a certain amount of loyalty (guilt?) I feel. That said, as I was walking in the back door to the place, I had a flashback to some previous visit where I did not get the warm fuzzies. I put that out of my mind: let's collect data!

Bruce was busy on the phone as I wandered into the showroom. The other rep was helping a woman with a Swarovski purchase. I surveyed the central display cabinet. First impression: there are a lot of empty slots... Still, I spotted a few candidates. Later, Bruce supplied some stats. All are 2" shaft eyepieces except the first Tele Vue.

make model fl
Tele Vue Plössl 40 43?! 120
Meade 5000 super-wide (green) 40 68 400
Tele Vue Panoptic 35 68 380
Celestron Axion LX
31 82 420
Meade 5000 ultra-wide (blue) 30 82 400
Celestron Axiom LX
23 82 320

The Celestrons and Meades are huge! They look massively heavy. Ungainly. Bruce reminded me that shifting the OTA in the rings helps deal with any weight or balance issues...

As much as I tried, I could not make myself feel comfortable. I don't think Bruce did anything wrong per se. But I just didn't want to leap... So, off to Khan. Maybe I'll bump into Ray or Eric...


As I walked into Khan Scope Centre, I saw Eric hunkered over the computer register. I said hello. Eric replied, "It's so nice to see a familiar face here." We chitchatted about space shuttles, lunar eclipses, old cars, and what not.

Onto the main event, Eric showed me a number of longish focal length eyepieces. For each, he calculated the true field of view. Nice touch. That let me get a very good impression of what I would see. But, as I surveyed what he had brought out, I wasn't bowled over. "Any other options?" I asked. "Oh, and let's pass on the 30mm Meade ultra-wide." Eric spotted some boxes on the lower shelf. "There are the Hyperions..."

He brought out the 31 and 36 mm models and opened the box for the 36. It is an attractive looking eyepiece. We crunched the numbers: 36mm with a 72° AFOV yields a 1.3-ish degree TFOV. Nice! That's what I'm after. And the best news? Attractively priced! $269 for the 36 (and $249, I think, for the 31).

Sold! The baader planetarium Hyperion-Aspheric modular eyepiece comes with:
  • removable 2" eyepiece shaft
  • 1¼" eyepiece shaft adapter
  • soft case
  • 3 caps or covers
    • for the 2" shaft
    • for the eyepiece with rubber hood down
    • for the eyepiece with rubber hood up
  • "Phantom Group" coatings
The excellent price left me enough money to buy something else! So I picked up a 40mW green laser too!

I'm a very happy camper.

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