7mm TMB Planetary
Posted 01 February 2013 - 02:11 AM
I tested it on Jupiter and M42 and against a Baader Hyperion 5mm in my Dob-mounted Orion 8" Newtonian.
The TMB compared very favorably. The 58 degree TMB can't equal the 68 degree Baader and the magnifications aren't exactly the same, but side by side the TMB easily holds its own.
Both eyepieces seemed to have similar slight color fringes near the edge of the field of view. Both were clear and sharp. I may have been able to detect slightly more detail in Jupiter's banding with the TMB. Both showed nice fine details in M42.
About the only interesting difference was a slight "internal reflection" with the TMB which seemed to actually be a reflection from inside my eye, judging by the way it moved, though this was not distracting enough to warrant any more than a passing mention.
Since the cost is dramatically lower ($40 vs $130) and the size and weight is also different (Baader's 14.7 oz vs 5 oz. for the TMB) I would easily recommend this for anyone considering it.
Posted 01 February 2013 - 03:07 AM
The reflection would indeed be from your eye because Jupiter is just so bright. I think all longer ER eyepieces do this, including my Pentax XW.
Posted 01 February 2013 - 09:25 AM
My 8mm TMB should be arriving today, looking forward to first light for it, but seeing has been atrocious here lately...CSC is white for days and anything over 100x has been pretty futile lately. Lately I've felt I'd have better luck seeing bands on Jupiter with the naked eye!
Posted 01 February 2013 - 10:30 AM
Posted 01 February 2013 - 12:39 PM
I started out with the 7mm liked it so much that I found a used 9mm and bought that one as well.
I now have the complete set of TMB's from 4mm to 9mm
Excellent value, great views.
Posted 01 February 2013 - 01:39 PM
Posted 02 February 2013 - 12:46 AM
I have the 7mm TMB II and find it very comfortable to use, and very good for the price. I use it on double stars more than I do planets with the 10".
In a 5" SCT I like it for bright globulars, and for bright planetary nebulae with a UHC filter.