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9mm Antares orthos first light

Started by tomhole, 09/05/2003 09:23AM
Posted 09/05/2003 09:23AM Opening Post
I tried out the 9mm Antares orthos from Hands on Optics tonight on Mars.

Short answer: the 24 Pans @ 250x were much better than the 9mm orthos @ 267x

Long answer:

Equipment:

Orion XT10, 9.4", f/5 dob
Televue binovues, 2x corrector
24 Pans
9mm Antares orthos
2x tv barlow
3x tv barlow

Seeing: 4-5/10, transparency: thin haze

First up was the 9mm orthos. Just the binovues and the 2x corrector for 267x. Kinda nice not having 8" of bino train hanging there at high power. Mars was washed out and pale. My benchmark for detail was the double fingers at the end of Sinus Meridiani. Not visible in the orthos. The 45 deg AFOV is very clinical. Blah.

Switched to the 24 Pans, 2x corrector stacked on the 2x TV barlow for 250x. Much more color and detail than in the orthos. Much, much more. I could easily see the 2 fingers of Sinus Meridiani and the overall contrast had much greater depth. The 68 deg AFOV made me feel much more involved with Mars.

I cannot explain this. I switched back and forth many times to try and figure out if the orthos were just much brighter than the 24 Pans and that is why they were so washed out, but I couldn't determine that for sure. They looked pretty close to me. I thought it might be the seeing, although 17x difference in magnification
shouldn't be that big of a difference. I tried 360x in the 24 Pans (3x tv barlow) and the seeing was holding up.

I'm going to get up for Saturn and see how it looks between the two. This initial look certainly is disappointing. These ortho planet killers were supposed to save me a great deal of money. I'm rooting pretty hard for them, but they need to make a strong comeback on Saturn. That darn 45 deg AFOV is killer, though. Not
sure how anyone could use these in a non tracking telescope. Big handicap, IMHO.

More to follow,

Tom
Posted 09/05/2003 03:47PM #1
Wow, thanks for the heads up. I'll hold off ordering more Antares Ortho until I spent more time with my 12.5. I don't have 24Pan; when I tried to Barlow (2X Ultima) my 30 Ultima, eye-relief was thrown forward leading to serious blackout. The TeleVue(s) probably work differently.

Hope the sky stays clear this weekend.

-- William