Sky and Telescope
wide field eyepiece
Ultra Wide Angle design, 80 degree apparent field.
Under fair skies, I set up my 8" Meade Starfinder Dobson with my new Meade Ultra Wide Angle 4.7mm 82° AF eyepiece. The sky was yielding
mag.4 stars, (naked eye), and was clear to within 5° of the horizon in all directions. After time for the telescope to equalize with the
95° temperature, (at 10:00 PM!), the search was on for the deep sky hunt.
The first impression was the comfortable eye relief (7mm). Not too much so to give any off-axis blackout problems, but enough to be well
away from eyelash contact. I will be interested in the effect of my eye fogging it in the winter months, but on to the review.The second impression was the WIDE angle. I mean WIDE. The really
nice part was the lack of any noticable field curvature (or pin cusion effect), at the edges. This eyepiece was well corrected. The
contrast seemed good, but a bit dark, I guess due to the amount of lenses involved. I knew there would be a bit of a trade off, but I
was really surprised at how bright it was even so. For instance the Ring Nebula was nicely contrasted, with the impression of several
wave patterns to the surrounding rings, as well as the central point showing a hint of the star with averted vision. This made me want to
try out the view on the Dumbell Nebula. I nearly fell backwards at the startling view. It just seemed too close. There was plenty of
filamentary structure to be seen. The bright areas wer very bright and the dimmer areas were still easily resolved. And all this under
The second test was to see how this EP stacked up in the binary
splitting scene. While in the area, I went for the famous Double-double in Lyra. They were easy as pie to split. Actually this was the
first time I had truly seen any real contrast between the elements. Up to now it had always been a noticable double pair, because of the
elongated point-like image, but not now. The split was clean with only my inexpensive focuser to blame for the difficulty in holding
the view in focus. The double 67 Ophiuchi and 70 Ophiuchi were easy as well. This was a real pleasure as I had never been able to pick up
enough contrast at 260x before to split 70 Ophiuchi.
The next morning at 4:30, I awoke easily craving the chance to test this EP on the planetary showcase in the Eastern morning sky. Again I
had to wait for my scope to "warm" from the indoor air-conditioning to the outside ambient temperature of 80°! The first planet had to be
Saturn. It was incredible to say the least. I wasn't seeing it this clearly last January at zenith! The Cassini division was razor sharp.
The shadow of the planet on the backside of the rings was jet black and easily seen. The cloud bands were noticable and several Moons
were easy to pick out. I did notice a slight bit of ghosting as this bright object sped across the .32° true field view. Was this going to
be good for bright views? Only one way to know for sure. Venus was blazing bright. The false color separation became noticable here.
There was a bit of blue on one limb, and a yellow rim on the other. The problem didn't keep me from discerning the true shape, but I
couldn't view for long. I slipped in the polarizing filter and the effect subsided a bit. Jupiter was essentially the same with a bit of
chromatic abberations showing due to the brightness, but the orb revealed its cloud bands and sharp edges fine. The moon Callisto was
very near the lower edge of the planet and was easily separated from the large planet. The contrast was still holding up very well even
under these brighter views.
All in all I was impressed with the flat field and high contrast in this eyepiece. The design is very good, and if it weren't for the
superior coatings, the view would really suffer from ghosting and eye
reflections back into the eye lens. In dimmer views the lack of dark-enhanced edges on the field lens end gave a light ring around the
edge. This could also be due to my eye dialating beyond the pupil exit distance requirements for this shorter eye relief, allowing me
to see the edges of the eye lens mount. It only seemed to be noticable until I found a nice object to view. The difference between
this Ep and my other high power Celestron 6mm Nexstar Plossl was vast. The cost difference was vast as well, but I will say this was
worth every penny. A "good buy" in my book.At your next star party, ask around. I'd bet you can find one or two
of these to look through. You won't be sorry you did.
Submitted by David - firstname.lastname@example.org