4mm University Optics Othor vs. 4mm TeleVue Radian

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The Review

Having been involved in this hobby, off and on, for nearly fifteen, years, and I've looked through my share of eyepieces. Like many, age and disposable income have allowed me to build a collection of very nice premium eyepieces. Still, I am a firm believer that many telescopes and eyepieces are better than most observers, and there is no substitute for knowing how to use your equipment well. I also like value. Money solves many issues, but value is a rare find. Often, we pay a high premium for that last 5% of performance that 
more-often-than-not will make little difference, even on those exceptionally rare perfect nights. 

So it was with value in mind that I purchased the little Ortho. It arrived unscathed on a clear and steady night with Jupiter and Saturn high in the sky. It was a week day, so I pulled out the Pronto and went to work. Well, the first thing I notice is that the eyepiece would not come to focus in the Pronto. I solved this by replacing the Televue 2" - 1/14" adapter with a lower 
profile model. Mechanics solved and scope cooled down, I focused on Jupiter. Most nights the Pronto will yield the N&SEB on Jupiter easily, but with little detail resolved. I had used the scope two nights before and obtained exactly those results with my 4MM Radian at 120X. 

Placing my eye to the Ortho, I noted the none existent eye relief (your eye is right-up against this baby) and focused. Well low and behold, tonight I was seeing four bands on the big planet and a hint of detail in the equatorial zones. Contrast was also very strong. Could it be that this eyepiece offered equal or better performance than by $230 Radian? I quickly went inside and pulled out the premium eyepiece. Allowing my eyes to adjust, I took a last look through the Ortho and then swapped eyepieces. The Radians larger field of view and eye relief were welcomed, but the view and detail was no better than the Ortho. Swapping back and forth I could not reach any firm conclusion, but for some reason I preferred the Ortho's view. 

On to Saturn, and it became apparent that the UO eyepiece was indeed throwing up a view that was slightly sharper and more contrasty. The Cassini division was evident, as was the planets shadow on the rings and even shading detail in the planet itself. These were also present in the Radian, but with a slight softness and some loss of contrast. The difference was almost imperceptible, but I think it was there nonetheless. 

Conclusion

I am going to keep this little eyepiece and maybe order a 6MM. To be fair the Radian offers a more comfortable view with a wider field, but in terms of shear performance, it was a dead heat with favor going to the Ortho. There is alot of value here. For planetary views the 40 degree field of the Ortho is of little concern, especially if your using a mount that tracks. If you can deal with the short eye relief, this is a fantastic eyepiece in terms of sharpness and contrast. I can't wait to try this in my larger scopes, but I'm glad I used the Pronto. Its was delivering exceptional views of the big gas giants on this night, and really showed what a small scope can do. While optically no slouch, its not an APO, so my experience should be readily reproducible with a modestly priced, larger achromat. 

Submitted by Anthony Valvo