ultrascppics vs UO orthos (old and HD)

Hi,

I am looking for eyepieces for binoviewing and was wondering which would be sharper and give better contrast for planet viewing, ultrascopics or uo orthos (old or new HD)? I have read good reports on both and need eyepieces in the 20 to 10 range. I have heard around 10mm the ultracopics get harder to use than an equivalent ortho and maybe I should mix orthos (9 & 12) and ultrascopics (20 & 15) if they are really close in performance.
Thanks.

Dave

I have used both the 10mm and 12.5mm Ultimas/Ultras and the 12.5mm and 9mm UO orthos in side-by-side comparisons. All are excellent - very sharp with excellent contrast for both planetary and high power deep sky observing.

From an eye relief perspective, the two lines are very similar. It is easier to take in the full FOV on the orthos because they have a narrower 45 degree FOV. This can be a little bit challenging on the Ultrascopic line not because their eye relief is significantly shorter, but because their FOV is a wider 52 degrees. In reality, what I can see in the Ultrascopic with glasses is the equivalent of the Ortho's FOV, and the Ultras beat the orthos without glasses.

At 9-12mm, you can't go wrong with either one, and it doesn't hurt to mix. However, at 15-20mm, I think the Ultrascopic wins hands-down, particularly with its wider FOV. My 18mm Ultima (same as the Ultrascopic) is my favorite eyepiece in my case and has wonderful sharpness, contrast and eye relief.

There is absolutely no reason why you can't mix and match as you mention. I did so and like both eyepiece lines. Personally, I prefer the Ultimas/Ultrascopics over the orthos for its wider FOV and the fact that they are parfocal, making a great set for planetary work.

Here's a suggestion to solve your dilemma. Pick up one of each at the 12.5mm or 9-10mm focal length without your binoviewer ($45-$55 for each used on Astromart). See which you like better on Saturn and Jupiter this winter, not just in the view, but the comfort factor for your eye. Then, you can be certain which type you like better before investing more in pairs of either line.

Don't fret over the differences too much, however. You really can't go wrong with either eyepiece line. Both are exceptional.