Harry Siebert Ultra Series

Looking for a good wide-field eyepiece with adequate eye relief at the 9mm point, I found these on Harry's web-site. Seem to have everything in one package: 9mm focal length, 16mm eye relief, 70* afov, all for less than two hundred dollars. Has anyone here tried these, and would you care to comment, please? Thanks!
Larry Seguin
Taos, New Mexico

Larry,

I have the 7mm, 11mm, and 15mm Ultras. These are great. I also had the 22.5mm and the 30mm but these latter two did not handle a fast mirror well at all.

But 15mm and smaller are wonderful in a fast scope. The afov is very generous and although I never measured it looks to be a real 70 deg as it is much larger than a Radian. In a fast scope (I have an f4.7) about the central 66-75% is corrected very well. After that some coma and astigmatism starts. Of course the 15mm shows more, the 11mm much less, and the 7mm almost none so it's entire field is really good.

All have very little CA. Some on the edge but you have to hunt for it. They also put up a quite small star point size. Much smaller than others I have tested against (UO HD, Radian, etc.).

They seem to be quite color neutral. On-axis very very sharp too. Wonderful for lunar viewing. On planets, Jupiter in particular, the 11mm brings out the best banding details of most all my EPs, perhaps tied with Radian which does very well in this department.

Contrast wise they are not as contrasty as a Radian or UO HD. Perhaps a tad behind the UO HD. Even so, they do a great job on opens and globs. Very nice added context with the wide field.

All in all they are quite a great eyepiece in the 15mm and shorter focal lengths. Harry does not advertise a 5mm but says he can make one up. Actually I feel they do a bit of a better job than his Star Splitters. Even though I have BO/TMB Planetaries (which for me are a better choice than a Radian, especially given price) and UO HDs, and I don't need a 5mm Ultra, I am still debating getting one made up to add to my stall. At 70deg afov these hold a nice niche in the marketplace, especially for the price and performance level. So would be nice to round out my series so I had a 5mm, 7mm, 11mm, and 15mm. Add to that my 24mm TV Wide Field (to be replaced hopefully by a 24mm TMB Paragon when it comes out for a pincushionless fov) and this group of 5 EPs gets me everywhere very well all at 65-70deg afov. Hard to beat that.