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And the Seibert Ultra 7mm
Guys,
I obtained my 7mm Ultra a few days ago and tried it out last night.
Good points:
Light
Cheap
Sharp field
Comfortable and useful eyecup
Bad points:
Cosmetic finish is very ordinary
Abominable reflections
I was pleasantly suprised by the sharpness across the field. Most of the field was nice and crisp, even in the f5 scope. On globular clusters, and little open clusters, the view was nice, with a fairly cool tone.
However, on bright objects, this thing reflects nearly as much as a main mirror!
There are reflections off every surface, and due to this, the splitting of doubles is a joke, you just get two bright stars with a smudge between them at about 30% of the brightness of the stars.
Saturn, forget it. Bright ghosts constantly wander around the image, making it a wholly uninspiring event.
With this shorter focal length, the ghosts are often right on the object being observed.
Up against the 9mm Nagler, there is no contest. Cosmetically the Seibert looks like a backyard job. Visually the Nagler is sharper, and has much better contrast. I popped the 13mm Nagler in a 2x Barlow (making approx the same focal length) and it was far superior, both in contrast and lack of reflections.
Seibert continualy writes about people favourably comparing his eyepieces to Naglers. Wishful thinking I suspect.
Cheers,
Jason.
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