wrose New Member
- Skill Level
- Time with Product
Dec 26, 2006
- User Notes:
BO/TMB 6mm Planetary, Original with new retaining ringPros:
Sharp views, very crisp, Generally good color and detail, Nice adjustable eye guardCons:
Reflections on bright objects, Eye relief is a tad short for eyeglass wearersComments:
First thing you need to do with this eyepiece is install the new micro baffled retaining ring that's delivered with the eyepiece. This eyepiece has no astigmatism. Eye-relief is about 14mm as stated by Burgess. The adjustable eye guard works well and the coatings are good. The barrel has a wide undercut safety groove that's a little bigger than most.
If you look very carefully there is a tiny bit of false color just at the edge of the FOV, but it is very slight and only at the extreme edge.
The eyepiece even with the new ring, has a broad reflection when observing the moon but it's not terrible. (the new version of the 6mm does not have nearly the amount of reflection.) This eyepiece design has a problem with internal reflections on bright objects like the moon according to 'Evolution of the Astronomical Eyepiece ' by C.J.R. Lord. It's not as noticeable when observing Jupiter or Mars but still present and causes the very to have a slightly washed-out color although the detail is good. (Regarding the issue of light scatter with these eyepieces, it's really only a problem when something very bright is right at the edge of the field. The scatter really only affects Lunar viewing or if you're trying to view something within a degree or so of the Moon. With the later version or the original version with the new ring, planetary and double star viewing is unaffected unless your target is next to the Moon.)
For viewing DSOs like galaxies or star clusters, the eyepiece has good detail and contrast. Nice sharp views, very crisp across 90+% of the FOV. The field is large enough to view Deep-sky objects easily with a Dob. In a Dob the field is sharp to within 10% of the edge, then you'll see a bit of coma from the mirror. This eyepiece does not seem to exaggerate coma in my Dob like some other eyepieces.
All in all it's a good eyepiece for the Garage Sale price of $49. Far better than your usual Plossl. There are definitely better eyepieces but not many for this price. On the basis of performance for the price, I give this eyepiece a "Very Good" rating.Sort by