7.5mm Orion Ultrascopic



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Date: NA
Price: $79.00
Design: Multi-coated 5-element Modified Plossl
Description: Surprisingly an extremely small and lightweight eyepiece. The coatings are excellent as is the construction. Somewhere around a 52 degree FOV.


This eyepiece came shortly after I received my new telescope. It arrived within five business days of ordering and was undamaged. My first inspection of it revealed excellent coatings on the lens and a very sturdy construction. The lens takes a deep red hue as you look at the coatings, very nice.

My first few trips out with this eyepiece were fairly boring. The planets were still under the horizon and the moon was not out. Not being a huge deep sky observer (probably because I live under mag 3.0 skies) I really did not have many uses for it. I did however use it to clearly split the Double Double in Lyra and a few other close pairs. That was it until the moon came out a few days later. This eyepiece offers excellent lunar images and is a touch sharper than my regular 10mm Plossel. With the planets now high in the sky I have been able to use this eyepiece at 133x (no Barlow) and 266x (Barlow) with great results. Jupiter shows tons of detail and Saturn is breathtaking. The disk of Saturn itself regularly shows a tremendous amount of detail and the rings give it such a three dimensional feel. This eyepiece has easily been my favorite lately with the planets high in the Eastern sky.

This eyepiece by far gives me the widest field of any I own. Better yet it is sharp from edge to edge. Truthfully I don't think I have ever detected any really negative edge of field effects in this eyepiece. This could stem from the fact that the edge of the field is so hard to actually observe due to its size and the deep black field stop on the inside.

There are a couple of downsides to this eyepiece. On some objects like fairly faint doubles or globular clusters it does not seem quite as bright as my 10mm Plossl. This could normally be explained by calling to attention that a 7.5mm eyepiece should be a little fainter than a 10mm eyepiece, but I have the feeling that the extra glass involved in this design may detract slightly. Also it is really a tight fit into my telescope. Almost everything I have put this into takes some work. My diagonal is too tight as well as my Barlow and my filters. It fits but it takes a little extra to get it in. The most annoying part of this is that some filters seem absolutely impossible to screw on.

Submitted by Curt Irwin - irwincur@excite.com - Grand Rapids, Michigan

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