Telescope Reviews: New eyepieces for my binoviewer

I had a chance to test the new GSOs through some sucker holes this evening and they confirm my initial findings, for the most part. I looked at the Moon, through sucker holes in a very clear sky, but the seeing wasn't so good and often terrible.

The eyepieces are razor sharp in my 150mm f/8 Sky-Watcher achromat, stopped to 120mm f/10 and a 1.7x GPC in the Zeiss T2 prism on the bino. The 20mm is slightly unsharp near the edge, but the effect is so small that it's hardly noticeable, since you don't tend to look at objects close to the field edge in a 70 degree field eyepiece anyway. The 15mm is so close to perfectly sharp across the field that it's hard to tell that it isn't and the 10mm *is* sharp edge-to-edge.

First in the bino was the 15mm's and my first thought was: "My goodness, these are as sharp as orthos!". And they are. I couldn't get enough time to compare them head to head with my UO VTs, but I did pay attention to what I was seeing and what I was seeing I was extremely impressed with. No ghosting, no glare, no lateral color, extremely bright, clear, sharp images with neutral tone and extremely comfortable eye position. This was also true for the 20mm and 10mm.

The 10mm turned out to be far more comfortable in use than I had anticipated, once I folded the eyeguards down. I have the same issue on my 10mm TS kellners. Frankly, I was extremely impressed with the 10mm's. They felt like 9mm UO's on speed, if you know what I mean. I tested them head-to-head with the 10mm TS Kellners and could see *no* difference in brightness, contrast and sharpness. The GSOs were more comfortable and had a far larger apparent and true field that was sharp to the edge. The 70 degree field of the GSOs were easier to take in than the 50 degree fields of the TS Kellners. To put it bluntly, the GSOs kicked the poor Kellners so far out the eyepiece box they still don't know what hit them. It was a total knock-out in the first round.

The biggest issue so far is that the 20mm's can't reach focus without a GPC. Bummer. I didn't get a chance to see if this was true for the 15mm, but I suspect so. I also didn't try the 10mm's without the GPC, but it seemed to reach focus a little further out than the 10mm Kellners, which do reach focus without a GPC, so it would seem the 10mm GSOs should also be able to do so. If so, I am very happy, since I used the 10mm Kellners a lot without the GPC.

I suspect I will have tons of fun with these and they should be absolute killer for deep-sky. Can't wait to take a look at M13 with the C8 and the 10mm's!

Clear skies!
Thomas, Denmark

Edit: The dust motes in the 20mm turned out to be less of an issue than I had thought, but it's still mildly distracting, just like splattered bugs on your car windshield.

"Damn Saturn-flies, getting all over the hood and windshield of my spaceship and I just ran out of bonus tickets for the local spaceship wash. Just typical!"

Edited by Astrojensen (02/04/12 06:10 AM)