Short Televues and TBM's Are they worth it?

[alan potts]

Televue eyepiece are expensive, orthoscopics can be difficult to use but will the TMB 2.5mm cut the mustard and will the TMB 6mm fend off the mighty Delos?

Are Televue eyepiece worth the money, this is a question that has been asked one way or another so many times on site in the period of time I have been a member that I  have lost count. Is there really an orthoscopic with good eye relief that many can afford.

I was loaned two eyepieces bearing the famous name or should I say acronym TMB the initials of the sadly departed, Thomas M Back. The man was by all accounts a very fine optical designer and I know had a company that sold some very high quality telescopes.

After receiving these eyepieces I was made aware of a very fine and well write report on site by Chris C, this helped me no end as I feel I had one eyepiece that was somewhere near the design that Thomas had specified and one that was clearly not. Whether this was the result of an unscrupulous Chinese factory trying to jump on a band wagon or just one that slipped through the net of quality control I will never know. I hope it was a case of the latter, though I am aware of reports of factories turning out eyepieces on the back of his name, no pun intended, without any funds ever going back to the late designers company of family.

The first eyepiece was a 2.5mm Planetary and the only pieces of equipment that I own that could be used against it were the 6mm-3mm Nagler zoom and the somewhat underrated

3mm Radian. Now these eyepiece will not appeal to all, they are very much in the short fast refractor category and if I am honest even the 3mm for me is a bit short on anything but the best nights and then only on a handful of targets. Because the field of view on the TMB and the Radian are the same at 60 degrees I decided to use this 90% of the time. We have now to give some thought as  to the cost of these.  The TMB comes in at about 60 Euros, so that is a bit less than 50 pounds where as the Radian even though it has been price slashed to 135 pounds is almost 3 time the cost, but is it almost 3 times better? Both have very good eye-relief and are easy to use, but as you would expect the build quality of the Televues outshines that of the TMB.

Alan  Picture.

I have decided to test these two only on a few bright targets and only in my shortest scopes. These just happen to be refractors which are the 115mm APO and the 70mm ED, at F 7 and F 6 respectively. This is not the most savage test for an eyepiece but F 6 is getting there and I would have thought it unlikely that anyone lucky enough to own a super fast F 4 Borg would use it either for photography work or with suitable expensive eyepieces that can handle the speed.

I started this test what seems like almost last year as the weather has been so unlike the Bulgarian clear skies I am used to, winter is normally cold that can served up some superb seeing, it has done in the past. Still that will serve me right for all too often telling you all how good I have it over here.

TBM Burgess 2.5mm and 3mm Radian and 115mm APO.

These observations are from 4 nights of good to very good seeing 6 weeks apart, total scope time was 7 hours 20 minutes, which I feel is more than enough on a handful of targets. There was rather more power gap here than I like as this can have a effect on what we see and think of an eyepiece and of course we are not comparing apple with apples. The TBM/Burgess planetary was delivering a whopping X322 and the Radian a still large but more acceptable X268, X 54 difference is a bit more than I would have liked. 

The Moon.

With the clouds spoiling things for me the first observations are from a five day old Moon, this is a time when I like it the most as it seems to be just be that much more interesting than when it is close to full. Condition were very good this night and was I would say the best night I had had so far this year, which is just as well given the power being employed.

I spent a good deal of time looking at various small craters peppering the floor of Mare Tranquillitatis and around the larger craters Madler and Theophilus, please don’t think I know these names, I cheat. The terminator always throws up some stunning views especially when it is totally dark. Many times rightly of wrongly I spend time viewing the Moon as it is getting dark and I dare say many members do as well.

Although these magnifications on the 115mm are a bit beyond what I would normally use, the Moon is the one body where we could be forgiven, being so much brighter than anything but the Sun, which I have yet to see at night. I would say here straight away the Radian was much punchier with the view it delivered, having more contrast and sharper, this was not totally down to the difference in delivered power I am sure. The 2.5mm TMB seemed a little more washed out than I would have expected but it was still sharp across its field of view which I consider a big plus. The TMB almost gave the impression that I was looking through the very slightest soft focus filter, like I used to use when taking portraits with a camera or very thin cloud. Now some of this was for sure the extra coal on the fire, but not all, the transmission of the Radian I would have expected to be better even with the multi elements construction and I am sure it was. There was no doubt that the TBM delivered many pleasing views which were better than through some of the eyepieces I have used in the past that cost much more.

Mars.

Mars was in prime position with only a few days since opposition and seeing  I would say good without being anything to write home about. This planet for some odd reason has never captivated me in the same way as Jupiter and Saturn and I think this has something to do with the disc size, so much more magnification is needed and then we are battling the conditions which are never good enough for long enough.

I was well pleased when I could see some darker shading detail which was triangular in shape and something one side of the disc which was most likely the polar cap, there was an area the other side to the cap of much light appearance which I believe is called Hellas, it’s all Greek to me.

Switching to the 2.5mm was not the disaster I thought it might be but there is no doubt that seeing was playing a part as well as the other factors in the equation. The image was not as good but was this the fault of the eyepiece, I don’t believe so, if I had a scope where this eyepiece delivered around X200 with the TMB plugged in then I am sure I would be very happy.

I could see the same features that I have mentioned but there was drift in the seeing making them come and go to a larger extent than with the Radian and there was a lack of definition but we are at level eleven here on the scope.

Jupiter.

I did try Jupiter on two occasions and I have to say this was rather too much power for the conditions even with the Radian on one night and it was not a great deal better the next time. I could see the equatorial belts but there was a complete lack of in your face contrast about the disc and using the Nagler zoom to punch in around the 4.5mm mark brought this home to me strongly.

I always believe less is more with Jupiter, rarely venturing above X200 on any of my scopes, I love the sharp punchy views where you strain to see ever nuance of detail on offer.

It goes without saying that the disc was something of a washout with the 2.5mm as over X300 was never going to help matters on any night. Using this power on say a 14 inch or there about is one thing but on a 4 ½ inch refractor, even a dam good one, is not the most intelligent thing I have ever done. It sort of reminded me of the days with my 3 inch refractor from Dixons all those years ago when I piled on X600, saw a very large dim disc but that was all, why did I do it, because I could probably and I am sure I am not alone here.

70mm ED refractor.

With this little scope having a focal length of 420mm the magnification come back down to earth somewhat, the Radian delivers X140 and the TBM 2.5 a not to insane X168. Immediately the difference is much smaller and there is at least a chance that a true comparison in on the cards with the gap being below X30.

The Moon.

All three nights I used this scope on the Moon, two were about the same state, at first quarter, something I have always found a little strange as half the Moon is illuminated. I spent a long time on the terminator looking for any differences in detail between the two eyepieces moving carefully from one set of craters to the next. I have to say that the Radian was better but not by as big a margin as I thought it would have been, the TMB was again just lacking a little attack and a tad on the sharpness stakes. Yes the Radian was a little sharper and yes the same was true on scatter and contrast but what this was dishing up for only 50 quid or so was worthy of merit. There was also a tiny amount of chromatic aberration at the very edge when I place the Moon so the limb could be seen there, though nothing to be too alarmed about. I managed to find a new rill on the Moon for a few seconds with 2.5mm which turned out to be a floater that had docked.

The final time with this scope was last night when it was just over first quarter and the conditions were really rather nice; still, not cold and above all very good transparency, the mountains were so clear I felt I could reach out and touch them, which of course I could if my arms were 20 miles long. It was much the same result with the 2.5mm providing a good rendition of all before it which didn’t quite match up to the two offerings from House of Televue. The 3mm Radian was providing that extra little crispness in the fine detail which I have say struggled to come through on the other two nights, this is of course the conditions which we are always fighting.

Mars,

I was not too hopeful as to what a 70mm scope of questionable quality was going to show on Mars and the answer was not a great deal.

The disc was clean and sharp in the Radian but I really had a battle royal to see anything trying to pass itself off as surface detail, but I just had a feeling I was seeing some shading to the southern part of the planet which was a bit triangular in shape. It was rather hard work, just reinforcing why Mars needs power, power that my poor little scope was almost out of.

The TMB was if anything worse, there was no sign of detail and there was also a bit of light scatter evident that I didn’t see in the Televues having used both at 3mm. The very good thing for the 2.5mm was the edge performance was extremely good for a budget eyepiece and I rated it only a little down on the on-axis image, there was however just a touch of chromatic aberration at the very extreme which did not bother me at all, but there was no such colouration from the Radian or Nagler zoom.

Jupiter.

I just had a feeling that Jupiter was going to be very good and I was not disappointed on either of the three nights, though last night I noticed that after 10 o’clock my time we were starting to say goodbye to it as an evening object as it was sinking very close to my walnut trees. I started off with the TMB first time out and at this time the planet was still well up in the sky and could be viewed long before it even got dark. The eyepiece showed me clear views of both equatorial belts and like last night all the moons were on one side of the main body, something I have not seen too many times and having this twice in few weeks period is strange indeed. Personally I prefer the two each side balancing act though this is of no importance. I did not see the Great Red Spot any of the nights, but then again I am not sure that a 70mm scope will show it, I rather think it will under the very best conditions. There was a small amount of scatter which seemed worse when placing the planet at the edge of field, this is of course not something I would normally do but is of interest to anyone with a Dobsonian that has to allow the viewed object to drift or forever be nudging.

The Radian was all round the better winning on everything apart from price new but differences between these two have opened my eyes a little, as good as Radians are this TMB really does try to punch its weight. There are no edge issues what so ever with the Televues and on-axis and off looked much the same to me, so good news for drifters. I think it was fair to say that the belts were better defined and I thought there was a hint of polar regions, nothing that really jumped out and grabbed you but they were there.

Sirius,

As I am somewhat addicted to this star, seem to spend half my winter scope time staring at it, I wanted to just get some idea as to how both eyepieces handle the brightest star in the sky. I didn’t spent much time with the Televues as I have spent plenty of time with this scope trying to see the Pup, which I never did, but this is a task I will again undertake next year as I didn’t think winter conditions were anywhere near as good this year. The TMB didn’t show the star as well with a good deal of scatter and distortion that didn’t seem as obvious in the other eyepieces and of course the pup remained in the kennel.

TMB 6mm Planetary 2.

This was the eyepiece that I was most interested in and wanted to put it up against my Delos 6mm, which I thought was going to be a very stiff test.

Now whether this eyepiece was one that was made by a TMB specified factory and managed to slip the QA net or it is an eyepiece that has been turn out by a totally uncaring manufacturer I do not know, but it is awful. If it is the latter this should never be seen to reflect on the reputation of the TMB Company, which would not be fair. I think most people know the market did have some lemons in circulation though and it would appear I have one. 

It is so bad off-axis that I made up my mind straight away not to waste time with it. I did however have it in the 190mm M/N outside on April 9^th and was looking at Mars, as the image was in the centre of field all looked reasonably good and I could see some detail and a polar cap. It was sadly a different story the moment I moved Mars away from the centre though, there was bad lens-flare radiating inwards which got worse the closer to the edge you went, this would make the eyepiece unusable for a Dobsonian owner and even at this price its unacceptable.

I can not recommend this to anyone but using a driven scope that can hold a planet in the centre the result was fairly good but not in the Delos league, on this eyepiece I think I have said enough.

Conclusions

Well the main meat in the sandwich was the 2.5mm TMB planetary and the 3mm Televue Radian, both performed very well indeed and I have to say surprised me, no shocked would be a better word. I was pleased that an eyepiece costing 50 pounds could turn in a performance of one costing at least double and be better than that. There is no doubt that the Radian is a better eyepiece but it is better by a smaller margin than I thought it would be. The report that I referred to earlier states that Teleskop Service in Germany offer TMB style planetary eyepieces that  are very close indeed to the exact TMB specification and have been marketed with the appropriate authorizations from TBM. There are a number in the series and if all are anywhere near as good as this it could well be a fine set of eyepieces that would please all but the planetary enthusiast. This is most certainly true of the 2.5mm and I highly recommend it as its overall performance was better than some more costly eyepieces I have used.

So I asked if Televue eyepieces are worth the money, this is always going to be a personal decision and for that I have to answer, yes they are to me, but if I find myself wanting something for very occasional use at the 2.5mm focal length then I would most certainly consider the TMB/ Burgess for the money I thought it was rather good.

Alan

[YKSE]

Thanks Alan! very much work behind this well-written review.

[michael.h.f.wilkinson]

Lovely detailed report. I remember the performance of the TMB/Burgess Paragon 40mm was excellent, so I am not too surprised that the TMB/Burgess planetary performed well. I am a bit surprised the 6mm was such a lemon.

[swamp thing]

Thanks for sharing Alan

The Difference in quality between the two TMB's is, as you say curious indeed.

[Dude_with_the_tube]

nice review Alan,very informative.

one thing people should also consider is the re-sale value of eye pieces if the times comes and you will be forced to do the un-thinkable and sell your collections.i very doubt that TMB,BST and everything else in this league will keep the value as your compared televues do.Your used Radian is sort of old design EP and has been replaced by newer models of TV range,however,despite this Radian still holds its value and is relatively difficult to come by as people still buy them and use them with great success as they are great Ep`s and great performers.i was looking for one and never found one when i was after one!

I will be not surprised that lets say 10 years down the road,Radians will become a collectors item same like first series smoothside naglers or TV plossls of the first vintage.

[John]

Excellent report Alan 

I've owned some of the original Burgess / TMB Planetaries and the Telescope Services HR Planetaries and they were very nice eyepieces. I didn't have any Radian's back then to compare them with but I have read reports that they compare pretty well.

I don't know anything about the TBM's though ??? 

[laservet]

TMB 6mm Planetary 2.

DPP_1935.JPG

This was the eyepiece that I was most interested in and wanted to put it up against my Delos 6mm, which I thought was going to be a very stiff test.

Now whether this eyepiece was one that was made by a TMB specified factory and managed to slip the QA net or it is an eyepiece that has been turn out by a totally uncaring manufacturer I do not know, but it is awful. If it is the latter this should never be seen to reflect on the reputation of the TMB Company, which would not be fair. I think most people know the market did have some lemons in circulation though and it would appear I have one. 

It is so bad off-axis that I made up my mind straight away not to waste time with it. I did however have it in the 190mm M/N outside on April 9^th and was looking at Mars, as the image was in the centre of field all looked reasonably good and I could see some detail and a polar cap. It was sadly a different story the moment I moved Mars away from the centre though, there was bad lens-flare radiating inwards which got worse the closer to the edge you went, this would make the eyepiece unusable for a Dobsonian owner and even at the price unacceptable.

Interesting review. Flare was a problem reported by several observers with the TMB/Burgess eyepieces.

The first run of the 6 mm had significant optical issues and Tom posted in the tmb yahoo group that when he tested the 6 mm he found that it wasn't even his design. But that was remedied in subsequent runs.

[alan potts]

Laservet,

This TMB planetary is direct from China and could well be nothing more than a sub-standard first run held back and then sold a rock bottom price to Dealers, my friend is a dealer. It was one reason why I tried to choose words with some care as I know this man was well respected and still sadly missed by many.

Alex,

Yes you know I like the Radians I would love a full set but there is not much chance of that here and when ever I come to England site members seem to snap them up before I get a look-in. Orthoscopic may well edge the perfomance but I know which wins the comfort.

Alan

[AlexB67]

That was an interesting read Alan. The BST starguiders are perhaps in a similar class, perhaps even slightly better some will say. I look forward to comparing my 8mm Radian with the 8mm BST but I expect that will be less straight forward, unlike the 6mm SW and 6mm Radian I had the first opportunity to compare two focal lengths. Of course I do expect the Radian 8mm to edge it, I would not have snapped it up If I didn't believe that, but ultimately the test will confirm that for me.  How comprehensive and long I will do it for will to some degree depend on weather and the temptation to sell the BST will happen in that time. After all keeping the two 8mm would be pointless, and I do need the funds to buy that mid power Delos.  May be that will be my birthday present next month    

[alan potts]

Alex,

A while back I did a review which included the fine Pentax XW 14mm which I had sold about three months before but the guy was coming to collect it when passing this way. I didn't quite get all the work done when he came for it, so in some way the Delos was winner by defualt. Never thought it was as good as the 7mm, 5mm and now 3.5mm. The 10mm is meant to be a cracker but I have never seen one.

I look forward to hear what you have to say on the 8mm battle.

Aan

[Luke]

Great review, Alan, thanks for your work on this

I have a 9mm TS HR Planetary and for me it runs my 8mm Radian pretty close, which is very impressive for the price I think. I spent a while trying to find fine detail on the Moon that I could see with the Radian that wasn't visible with the TS HR, but I had to give up. The main difference I felt between them was that the Radian was a touch more "effortless" and the view just a smidge clearer and more pleasing, the TS HR was sharp and reminded me of ... a Radian!

I use the 9mm a great deal for solar observing. I find it a comfy, compact, light, well made eyepiece that I am very fond of. Boy, I have seen some great solar sights with it.

[alan potts]

Luke,

As far as I understand the ones that Teleskop Services offer are a design that was offically approved by TBM, I am fairly sure the 6mm I was loaned didn't live up to that. I have heard from other sources that the TS HR's are very good however I can't see myself throwing my range of Pentax XW Radian and Delos away which fill the power end of my collection. It would be nice to try out some of the others because the 2.5mm seemed very good especially for the money.

Alan

[Luke]

Alan, that's interesting about the TS version. I wouldn't mind trying some other TS HR's either, though I have recently thrown my lot in with Delos for high power with my fracs. Can't wait to try the 3.5mm!

[nicks90]

my TMB 9mm looks identical to the 6mm you are testing - well the tmb optical II logo and physical appearance etc.

my views through it absolutely echo what you have said about the 6mm tested here.

appalling. its a complete joke. the supplied 10mm plossl from celestron i got with my astromaster 130 (well renowned for being a rubbish eye piece) does a better job. Off axis things just turn into a smudgy blur, everything has comet tails. reflections and ghosting on pretty much anything brighter than mag2 star - planets were just horrible.

I even took it apart to see if a spacer had become jammed and put the lenses off axis during production. Double checked a wiki on ep design to make sure some numpty hadnt put a lens in the wrong way round - everything.

nope, it was 'right', it was just rubbish and got thrown in the bin. Complete waste of £40

[John]

my TMB 9mm looks identical to the 6mm you are testing - well the tmb optical II logo and physical appearance etc.

my views through it absolutely echo what you have said about the 6mm tested here.

appalling. its a complete joke. the supplied 10mm plossl from celestron i got with my astromaster 130 (well renowned for being a rubbish eye piece) does a better job. Off axis things just turn into a smudgy blur, everything has comet tails. reflections and ghosting on pretty much anything brighter than mag2 star - planets were just horrible.

I even took it apart to see if a spacer had become jammed and put the lenses off axis during production. Double checked a wiki on ep design to make sure some numpty hadnt put a lens in the wrong way round - everything.

nope, it was 'right', it was just rubbish and got thrown in the bin. Complete waste of £40

Interesting feedback. Shame it bears the "TMB" branding. The late Thomas Back deserves better than that 

[alan potts]

Nick,

I tried my best to tread with care over this 6mm eyepiece as I know it came direct from China and could well be a result of shady dealing by an unknown . Thomas M Back was a very well respected optical designer and in an effort to provide the market with an inexpensive good quality eyepiece range got a bad deal somewhere down the line from Chinese manufacturers. Some of the range were not even to his design so I am lead to believe and others appeared in different focal lengths bearing his logo, which in my books is about as bad as it can get. That of course will not help one bit as you would appear have one of the lemons that did exist and is well documented. As I have said and other too, the Teleskop Services ones were to his approval and by all accounts work rather well.

Alan

[nicks90]

it is a crying shame that unscrupulous manufacturers have done this, because one of the reasons I bought that ep was based on the reviews of the TMBs. It was also my first ep upgrade and i was totally devastated and spent many an hour thinking something was wrong with the scope and not that it was because of some dubious 'clone' eyepiece.

I am actually after a decent 6mm ep for planetary viewing with my big dob - so its good to know the TS versions are what they are supposed to be and give good results.

[alan potts]

Nick,

I little more costly but if you can handle the eye-relief the astro Hutechs from FLO take some beating. You have to spend a silly amounts of cash to better them.

I fully understand what you have said about thinking the scope was faulty. There are lots of unscrupilous things go on these days, a friend of mine bought a Rolex in a what looked to be a classy shop in the Far East. The thousands of pounds price tag would have one believe it was real thing, it was a copy, jolly good one but a copy notheless.

Alan