I recently purchased three Paul Rini eyepieces in 16mm, 22mm, and 35mm. The purpose of this review is to focus on the 35mm Modified Plossl eyepiece (pictured here: http://img.villagephotos.com/p/2005-10/1086198/astroRiniEP003.jpg ). I also used the 25mm Explorer II Kellner that comes standard with the Observer 70 for the purposes of comparison. As a reviewer, I should note that I only have about a year of astronomy experience and have never used a very high quality eyepiece that retails for more than $30. Thus, I cannot say how this eyepiece compares to something like a Televue Radian.

Paul Rini is an amateur astronomer who constructs quality eyepieces from surplus optics and sells them at very affordable prices. I was able to purchase this eyepiece for less than $30. For my investment, I got an eyepiece that seems seems quite heavy, massive, and solidly constructed. My Rini eyepieces are pictured alongside an Orion Explorer II at http://img.villagephotos.com/p/2005-10/1086198/astroRiniEP001.jpg.

Since this was my first chance to use my Paul Rini eyepieces, I chose Orion as my observing target. I set up the field of view (FOV) in my 25mm Explorer II so that I could see the two stars on the left side of Orion's belt (Alnitak and Alnilam). With the standard Explorer II, I could see just a little beyond each star and they stayed focused pretty well near the top and bottom of my FOV.

Once I switched to the Rini 35mm, I could see a considerably broader field of view and the three smaller stars that sit above Alnilam (the middle star of the belt) were brought into view. I experienced some black-out or vignetting (where my view faded out) at times when I was positioned a little to far from the eyepiece. This eyepiece seemed to provide the 22mm of eye relief claimed on the Rini website. Also, because the exit pupil (32mm) on the Rini eyepiece was considerably larger than my own pupil, I found that I could move my eye around the eyepiece to expand the FOV a bit and see different stars.

Next I focused in on the sword hanging from Orion's belt. In the Trapezium, I could see that Theta 1 was multiple stars with the 35mm. I could also see that I was looking at a nebulous gas/dust cloud with the 35mm eyepiece.

From a beginner perspective, there were only a few minor drawbacks that I could see with the 35mm eyepieces. The 35mm eyepiece has a lot of glass surface and a couple of times I was distracted by reflections from the bright lights in my periphery. I was able to minimize this by cupping my hands around the eyepiece or maneuvering the hood of my jacket to block the light source. I think most observers probably observe from darker, more private locations, and would not have this problem. The other drawback is that the eyepiece covers supplied fit very tightly and take a considerable amount of work to get on and off of the eyepiece. In the cold, I was concerned that it might be easy to drop the eyepiece. Finally, it seems to strain my eyes a bit to look at stars at both the top and bottom of the FOV simultaneously.

In general, I thought that the 35mm Rini eyepiece worked very well. Stars remained pinpoints from edge-to-edge of the field of view. However, the images seemed a tad sharper when the object was centered. The quality of the views certainly seemed comparable to those offered by my Explorer II Kellner and my economy grade Plossl eyepieces. I believe the wider field of view could be very useful in remaining oriented when observing a constellation or asterism. This eyepiece is a quantum leap in performance over Huygens economy eyepiece designs that are commonly provided with department store telescopes. As a beginner, I thought this eyepiece was solidly constructed, worked well, and offered a very good value proposition. I look forward to using this eyepiece frequently.

Pros

- Excellent Value at $30 or less.
- Wide FOV.
- Crisp images.
- Very Solid Construction.

Cons

- Large exit aperture.
- Some blackout/vignetting if proper distance from eyepiece not maintained.
- Very tight fitting dust covers.
- Eyes strain to take in everything offered in the FOV.

Rating