Superviews they’re not

I bought a pair of 10mm GSO Superviews new to use in the binoviewer and give me some context when I go to higher power. The clouds broke this morning for a bit and I got a chance to test one in Cyclops mode in the Orion ST80, an F5 achromatic refractor. The view was less than super.

Well, significantly less. The point here is the center 50% of the eyepiece field is acceptable – after that the degradation is more horrendous than anything I’ve seen. I tried them on several objects, including Saturn, M35, and M42. At 40x I could certainly make out the rings of Saturn nicely and it’s a sweet sight at any magnification. But if I let the image drift very far from the center, Saturn became a colorful blob – not at all acceptable. I compared this with an Orion 10mm Sirius Plossl I bought used for $25. (The GSO was $37 new, hardly a bank buster. I bought it because my experience with a 42mm GSO Superwide was significantly better – but I still need to examine that eyepiece more carefully later, as well as the 15mm GSO SV I have.)

We’re talking a relatively small increase in FOV – from 52 AFOV in the Plossl to 65 AFOV in the GSO which in this case translates to 20 minutes or so. I didn’t attempt exact measurements – maybe another night – but my impression was that the usable field in the Orion Plossl was larger than the usable field in the GSO. I’ll try the GSO another night on F8 and F10 scopes. If I don’t see a significant improvement, they’re headed for Astromart! But I’ll have to be honest when I sell them, so I’m not sure I’ll find a buyer ;-)

On a brighter note,this was also a test of the ST80 and the new Celestron Alt-Az mount I got for it. Both did finde Makes a wonderful little “grab and go” scope and this was a “grab and go” situation. It was raining hard last night and I didn’t see any holes in the clouds until about 4 am. So I simply popped out on the deck for a few minutes with the ST-80.

No set up time – oh, a tiny, right angle finder ( 6x26) I added to it worked beautifully. The scope was easy to use, comfortable to use, and finding stuff was a breeze. My favorite eyepiece for reasonably wide field views is an old 18mm Meade SuperWide, though the 25mm Orion Sirius Plossl does fine as well. The mount was steady – there was still a significant breeze from the passing storm – and I found it simpler to pick up the whole mount/tripod and orient it in the general direction when I wanted to make a major switch to another section of the sky. (This means that you can always sit between the tripod legs so they don’t get in the way.)

The views of Saturn were delightful, as mentioned. They were best at 80 X – 10mm Sirius Plossl, plus 2X Celestron Barlow. Similarly, the Trapezium in M42 split at 40X, but was much nicer at 80x – and finally, it was a toss up whether to use 40X or 80X, but I think I’d prefer 80X when it came to viewing M35. At 80X you can keep an object in view smoothly with a steady, but light, pressure on the slow motion control. That said, from a motion standpoint, I suspect this scope is best used at 40X or less, (Why do we always want to push something beyond what it’s good for?)

Bottom line: I like the Celestron Mount. (For the record, this is the Celestron Heavy Duty Alt-Azimuth Tripod 93607 that I got from Optics Planet for $99.) I like the slow motion controls. The ST80 is nice, but awakens some hunger in me for a similar-sized apochromatic. I’m not at all impressed with the 10mm GSO Superviews. Though I hold out some hope for better performance with a longer focal length scope. The question is will it move up into the acceptable range/ Right now it’s well below it in my book.