All Other: Generic Series 500 Plossl Eyepiece - 4mm

1.0 Not very impressive!

Inexpensive

Poor eye relief; Couldn't get it to resolve!

I won this eyepiece in a contest on AstronomyRatings.com and mainly selected it because I had no other 4mm eyepiece. I was not anticipating very much and I was proved right!

I knew beforehand that the Plossl design had poor eye relief, especially at these short focal lengths and I was correct. You really have to get your eye pressed into this eyepiece to make it work! I had hoped that other than the eye relief it would prove to be similar to an orthoscopic, but I was sure wrong!

As I had no other 4mm eyepiece to compare it to, I made my comparison as best I could against the nearest other eyepieces that I have. These were a quite old EdsCorp 6mm Abbe Orthoscopic and a Meade 6.4mm Series 4000 SuperPlossl. There is no comparison!

I tested all three eyepieces on both my 100mm f/6 achromatic refractor and on a 102mm f/13.2 Mak-Cass. I tested the eyepiece on the Moon and on Saturn, which was quite high overhead.

The Ortho gave very good detail and was surprisingly sharp, even though it had poor eye relief. Of course I expected poor eye relief in all of these eyepieces. The Ortho gave good color rendition and even some banding on Saturn was noticible. The Meade Super Plossl was a good performer, but just didn't come up to the performance of the Ortho in either scope. It just didn't resolve detail the way the Ortho did. The Series 500 Plossl didn't even compare. In both scopes, it was almost impossible to get a good focus. On a night of excellent seeing, I just couldn't get it to resolve anywhere near the other two eyepieces. I know it wasn't the magnification because I used a 2x barlow with the Ortho eyepiece and it worked extreemly well! Maybe in just the right scope with just the right conditions, the Series 500 4mm would be OK. I just wasn't able to get it to perform!

I'm sorry, but I can't recommend this eyepiece. I would say, save up your money and get a good Abbe Orthoscopic or one of the newer "wide field" eyepieces if you need something at this focal length!