Antares W-70 EPs

Well, I have gotten a chance to test out 3 W-70 EPs in the last month or so. They were sent to me for evaluation. The 5.7mm, 14mm and 25mm models.
To keep it short I will post my observations.
The 5.7mm is a pretty good EP. It did not have any real problems with color, coma, astigmatism or curvature. In fact I thought it was nice over all. No more edge problems than a 6mm Radian in fact. I would rate it a good buy or even a little better than that. No, it was not quite a Radian, but it was very close and the cost is excellent. It looked much better than I expected with a good image edge to edge and good contrast. Eye relief was not bad in fact almost generous
The 14mm was not so good. It had a lot of field curvature, color, astigmatism and coma. In fact I did not find a lot about it that I liked. The on axis was OK, but the outer 50% was not good. Some internal reflection was present too. Eye relief was good.
The 25mm was good. Not as good as the 5.7mm, but much better than the 14mm. It showed some color and a little curvature. No astigmatism though that I could detect. There was a bit of pincushion, but this is not unusual for a wide FOV EP. I would call it a good value for the money. Good eye relief.

I had a 5.7mm W70 not long after they came out. I had problems with glare from an unblackened spacer (hopefully fixed in later models) and bright green coatings. I assumed at the time that the coatings were par for the eyepiece, but much later (a year after selling it, I think), I learned that some (most?) people got much better coatings. With both of these things fixed, the only other complaint I had was sperical aberration of the exit pupil. The eyepiece was comfortable to use on DSOs, Jupiter, and Saturn, but daytime and lunar observation revealed a tendency to kidney bean. The eyepiece was still usable then, but not by a wide margin. On the positive side, to the best of my recollection, the usual edge-of-field aberrations--field curvature, astigmatism, and lateral color, were as you have described.
--
Mike

It is my understanding that these eyepieces are slightly modified versions of the Synta Widefield/Expanse series. It is easy to see how this could be, the center section contains no optics and could be easily replaced to provide that distinctive rubber barreled look.

Of the Synta/Expanse series, I have owned the 6mm, the 9mm and the 15mm. The 6 had some serious ghosting, internal reflections, the 15mm is much as Floyd describes the the 14.X Antares WF.

The 9mm is by far the best of the bunch and performs nicely at below F5. Certainly a bargin. Both the 9 and the 6 have symth or barlows in the front section, probably responsible for their better edge correction. One can play mix and match, swap the optics in the 14mm for the rear optics in the 9mm and have a new eyepiece....

jon