6 replies to this topic

[Peter Besenbruch]

I received a TMB Planetary 2.5mm clone this week and got to try it out in a suburban park tonight. One look at the moon eased some worries I had about the eyepiece providing too much power. At 360x, the eyepiece provides 3x/mm or 76x/inch. I concentrated on Posidonius and its rille structure. I had applied felt in advance, so there was no flooding of the field of view from reflections off the eyepiece tube sides.

 

There was little turbulence, and while 100x showed much better contrast, at 360x, the contrast was still fine on the moon, and the scope (a 120mm, f7.5 ED doublet) focused easily. I was impressed. I was also happy to split Sirius easily at 280x, and Alnitak at 40x (22mm LVW) at the edge of  the field (something called M42 lay in the middle of the field). E and F stars of the Trapezium were easy at 100x.

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​I did a bit of comparing between the ortho 7mm in an Ultima Barlow and my 3.2 TMB Planetary clone. On the moon, the ortho was not noticeably better. I'm still waiting to get some good views of the planets.

[tomjones]

I've always liked the 3.2 and 2.5mm TMB's for extreme power views as there was nothing else at a reasonable price down there.  And the rest of the lineup was almost as good as TV Radians for the planets.

 

Decent price, $38.50 on ebay shipped free from Phoenix, lite weight, reasonable eye relief, almost 60 degrees, not huge bodied, and work good in f/5 scopes to boot, what's not to like.

Edited by tomjones, 14 February 2016 - 09:05 AM.

[Peter Besenbruch]

I picked mine up from Agena for $55. They offer "free" shipping to Hawaii. Looking at their 2.5mm eyepieces, I see the following:

 

1) X-Cel LX 2.3mm. I did not like the 5mm, so once bitten, twice shy. The price is low ($69), though.

 

2) Nagler type 6 2.5mm. It does cost a bit more ($310) than the TMB clone. I have never tried that one. Perhaps better in non tracking scopes.

 

3) SLV 2.5. Never used this one, either, though I have tried the original LV eyepieces. Those I found rather "yellow" in overall tone. The price at $170 isn't too outlandish, you get more eye relief, but a narrower field than the TMB clone.

 

These eyepieces sit mixed in with other types, orthos, Pentax XL, LVW, Barsta ED. It's a bit of a Mötley Crüe, but they all work well.

[E_Look]

I essentially exclusively use the TMB Planetary Series, the non-clones, all of which are of Series I except for the 7 mm, which is a TMB/Burgess with the silver barrel.  All have undercuts.  I have a f/4.9 reflector and I've even Barlowed my TMB Planetary 2.5 mm for superstupidongous magnification... and I wasn't disappointed (used it on Neptune and Uranus).  I don't notice any coloration; seems neutral to me.  Glare?  Maybe just a tiny bit.  I suspect much of it is reflection from my own eyeball.

 

I am pleased to see others enjoy any of them, given all the venom they receive from so many here on CN, which does confuse me a bit (on more than one level).  I truly feel bad they're not being sold new these days, as they are pretty good eyepieces, comparing to on-axis Plössl views and definitely superior to a Plössl off-axis.  Width of field?  I don't care: I have a motorized EQ mount.

 

What's more, they are incredibly cheap, making it possible for a guy who, like me, is tight on funds, to enjoy a little astronomy without resorting to YouTube or some such nonsense.

 

For the Moon?  Almost any eyepiece will do; you don't need TMB Planetaries.

For planets?  I can see all the detail my 8" aperture allows, seeing for example details on Jupiter, while my 8" cannot resolve them cleanly, others later with bigger apertures verify and explicate what I saw.  I "routinely" (haven't been outside in a while [snow is falling outside my window currently; never mind that, it's waaay subzero]) used to use the 2.5 - 5 mm TMB Planetaries on the planets with decent contrast and good detail, and Barlowing them on those nights of incredibly good seeing.

Oh, and Mars!  They do well on Mars... though you do need decent seeing for Mars.

 

Did I say they were pleasantly cheap for quality eyepieces?

 

Enjoy 'em gentlemen; I hope to be able to get some time to look through mine again soon.

Edited by E_Look, 15 February 2016 - 05:21 PM.

[Peter Besenbruch]

I essentially exclusively use the TMB Planetary Series, the non-clones, all of which are of Series I except for the 7 mm, which is a TMB/Burgess with the silver barrel.

 

​I have a TMB Planetary II 6mm which is well blackened inside. It doesn't have quite the snap to focus of the TMB clones. I got turned on to the series when I finally tried to use the 5mm included with the telescope. A single glance was all it took to convince me that this was a good eyepiece.

[bogg]

I have the TMB planetary II as well. I found the views to be a very good and believe it has been an underrated eyepiece 

[E_Look]

 

I essentially exclusively use the TMB Planetary Series, the non-clones, all of which are of Series I except for the 7 mm, which is a TMB/Burgess with the silver barrel.

 

​I have a TMB Planetary II 6mm which is well blackened inside. It doesn't have quite the snap to focus of the TMB clones. I got turned on to the series when I finally tried to use the 5mm included with the telescope. A single glance was all it took to convince me that this was a good eyepiece.

 

 

Actually, Peter, and forgive me for digging up an old thread, but it just occurred to me that there used to be a bit buzz back and forth here on the CN Eyepiece (and other CN) forums, that while the Series as a whole is rather nice, some have claimed that in their usage, the 6 mm might have been "a dog", that it just doesn't have the uniform edge-to-edge sharpness or flatness and lack of glare that the other TMB Planetary focal length units do.  Some have claimed also that later TMB had corrected this in the 6 mm unit; I used to think like they did also, but in the last few years, I don't recall any personal complaints in my heart when I've used the 6 mm.  Sometimes, the seeing and transparency can fool you into thinking an eyepiece is better or worse.

 

Eddgie, a prolific and long-time poster here on CN, has had some excellent ideas on testing the actual ability of an eyepiece by setting up the EP in your scope in your house and seeing how it does on things like graph paper lines, etc. to check for actual pincushion/barrel effects, sharpness across the field, etc.

Years ago, I promised to check for him, but never got around to it.  My apologies to Eddgie and to all of you.  Maybe someday soon I can still get to it!