10mm Radian

[Mark in Macc]

After months of rubbish weather and poor seeing, I finally managed to test my 10mm Radian in anger. I bought it second hand and it looks optically perfect. I had a 12.5 mm BGO to compare and tried both on Jupiter and the moon on Fri. The seeing was excellent, presumably due to the previous days rain clearing the air of dust. The BGO was good, but the Radian at 235 x was outstanding. The detail on Jupiter was amazing and the craters on the moon were mesmerizing. The upshot is, if you get the chance to own a Radian, it should be seriously considered. Mine was £100 and is flawless.

[kirkster501]

I have the 8mm that I bought from a fellow SGL'er and it is likewise wonderful. Shame so few opportunities to take that level of magnification though in the UK, especially on a SCT and especially this year!

[michael.h.f.wilkinson]

I had two Radian (the 8 (now with Kirkster) and the 10 (now with Mr Spock)). Both were really good, and very comfortable to use. I only replaced them to get the Pentax EPs I have now. These are better, but only slightly (law of diminishing returns).

[Charon]

My 8mm Radian will be for sale soon. I have replaced it with the Pentax XF8.5mm

[ollypenrice]

Hmmm, I think this may depend on your eyes. I actually prefer the Radians, though this is not based on more than a passing acquaintance with the Pentaxes so I may be out of order. I found a slightly hard 'edge' and colour in the Pentaxes I tried, though they were superb. Radians are good value second hand but I did some telescope testing with the renowned Ralf Ottow and we (he!) found that a Nagler, even with its wider FOV, was better at the edge than a Radian. (I was bemused to read a telescope review recently in which the reviewer, using a Plossl (!!!!) described the telescope on test as giving a clean stellar image across about 85% of the view. I think a better choice of EP would have made for a better test.)

Olly

[Naemeth]

Hmmm, I think this may depend on your eyes. I actually prefer the Radians, though this is not based on more than a passing acquaintance with the Pentaxes so I may be out of order. I found a slightly hard 'edge' and colour in the Pentaxes I tried, though they were superb. Radians are good value second hand but I did some telescope testing with the renowned Ralf Ottow and we (he!) found that a Nagler, even with its wider FOV, was better at the edge than a Radian. (I was bemused to read a telescope review recently in which the reviewer, using a Plossl (!!!!) described the telescope on test as giving a clean stellar image across about 85% of the view. I think a better choice of EP would have made for a better test.)

Olly

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Relatively clean image .

[ollypenrice]

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Relatively clean image .

Sorry, I don't follow.

Olly

[Mark in Macc]

I don't doubt that Naglers are better, but you don't find many second hand for £100. A decent second hand Radian is good value for money IMHO.

[ollypenrice]

I don't doubt that Naglers are better, but you don't find many second hand for £100. A decent second hand Radian is good value for money IMHO.

Couldn't agree more. I've two second hand ones, plus one I bought new, and I'm very happy with them. I think the supply of the right glass for Radian production may have dried up, hence the changes in the TV line-up.

We always think it's to do with marketing etc but glass production is going through a hard time, I'm told.

Olly

[michael.h.f.wilkinson]

Hmmm, I think this may depend on your eyes. I actually prefer the Radians, though this is not based on more than a passing acquaintance with the Pentaxes so I may be out of order. I found a slightly hard 'edge' and colour in the Pentaxes I tried, though they were superb. Radians are good value second hand but I did some telescope testing with the renowned Ralf Ottow and we (he!) found that a Nagler, even with its wider FOV, was better at the edge than a Radian. (I was bemused to read a telescope review recently in which the reviewer, using a Plossl (!!!!) described the telescope on test as giving a clean stellar image across about 85% of the view. I think a better choice of EP would have made for a better test.)

Olly

In my comparison, I found the Radians ever so slightly warm in colour tone, whereas the Pentaxes were very colour neutral. In terms of transmission, the Pentaxes also had the edge (small margin). Sharpness was roughly equal, but contrast was again slightly better in the Pentaxes. The XW win on FOV as well. I have only compared them in the rather forgiving C8 at F/10, although the Radian 8 and XF8.5 were also compared in the 80mm F/6.

I must stress the margins are small, and personal preferences differ. When I had them, I really enjoyed the Radians as very sharp, and very comfortable, and a step up from the Vixen LV 7 and 9mm I had before. In terms of comfort (very important during prolonged observations), the Radians might even have a slight edge over the XWs.

[andrew63]

Hmmm, I think this may depend on your eyes. I actually prefer the Radians, though this is not based on more than a passing acquaintance with the Pentaxes so I may be out of order. I found a slightly hard 'edge' and colour in the Pentaxes I tried, though they were superb. Radians are good value second hand but I did some telescope testing with the renowned Ralf Ottow and we (he!) found that a Nagler, even with its wider FOV, was better at the edge than a Radian. (I was bemused to read a telescope review recently in which the reviewer, using a Plossl (!!!!) described the telescope on test as giving a clean stellar image across about 85% of the view. I think a better choice of EP would have made for a better test.)Olly

i must admit i would have thought quite the opposite. I would have thought that the radian would be more 'orthoscopic' in it's field and be shaper than the nagler in the outer 20 percent. andrew

[alan potts]

I have had 3 Radians and still have 2. The 10mm went to an English on site owner and was replaced with a Delos. I still keep the 5mm and 4mm for high power and am puttind the 4.5mm Delos bewteen them before Christmas. I would also want either a 3mm Radian for the very top or a 3.5mm Delos. The Radians are excellent but I like the Delos just that tiny bit more.

Alan.

[Damo636]

After months of rubbish weather and poor seeing, I finally managed to test my 10mm Radian in anger. I bought it second hand and it looks optically perfect. I had a 12.5 mm BGO to compare and tried both on Jupiter and the moon on Fri. The seeing was excellent, presumably due to the previous days rain clearing the air of dust. The BGO was good, but the Radian at 235 x was outstanding. The detail on Jupiter was amazing and the craters on the moon were mesmerizing. The upshot is, if you get the chance to own a Radian, it should be seriously considered. Mine was £100 and is flawless.

Nice one Mark! I've owned a couple of Radians, 6 & 14mm, & I also found them to be excellent. Considering they can be bought used for the price of a Hyperion makes them a no brainer!

[bish]

I've got an 8mm and think it's great. I used to own a nagler too and liked them equally although for slightly different reasons.

[John]

I've owned all the Tele Vue eyepiece types except the Radian and the much more recent Delos. I really must have a look through a Radian one day (and a Delos for that matter) - I've read such a lot about the Radians I'm curious as to what they will actually be like. I've seen them described as the "bovril" eyepiece, ie: your either like them or dislike them. That sounds a bit extreme for a Tele Vue product though although there are folks who don't like Naglers and Ethos so it could be just how it is, I guess.

[alan potts]

John,

People not liking Naglers, now there is a good reason for hanging to be brought back. You should have a look at one at a star party there must be a good amount of them between the members on this site alone. I have the 6mm Delos and the 5mm Radian but I find it difficult to make any comparison between them as there is X30 difference in the magnification even in my 115mm refractor.

Alan.

[Mark in Macc]

Nice one Mark! I've owned a couple of Radians, 6 & 14mm, & I also found them to be excellent. Considering they can be bought used for the price of a Hyperion makes them a no brainer!

I know which I would buy given the choice. Interesting to hear the bovril (or marmite) comment. Does anyone know what this is based on?

[John]

I know which I would buy given the choice. Interesting to hear the bovril (or marmite) comment. Does anyone know what this is based on?

Actually I think it might have been marmite rather than bovril but the meaning is the same. I probably saw this opinion on the "Cloudynights" forum.

In fairness, we often say that the eyepieces that work well for us are quite a personal choice. Features that one person loves could well be not anothers "cup of tea" at all. There are lots of examples of this in the eyepiece threads on here.

So the bovril / marmite thing is not a criticism and might just as well be applied to virtually any eyepiece !

So you read up on the features / characteristics / specs of the eyepiece types and pick the ones that you think might suit you. At least buying Tele Vue you can be confident that you get the best of the type around.

[Moonshane]

I have two Radians (8mm and 10mm) and have owned a 14mm and 18mm previously. they are excellent eyepieces. personally I prefer the BGOs (I have 12.5mm, 9mm and 7mm) but there's little in it and the Radians do give the more comfortable experience. If I had to raise £200 quickly, I'd sell the Radians not the BGOs but I'd miss either.

I like having a lot of eyepieces at the sharp end. I have 3-6mm, 7mm, 8mm, 9mm, 10mm and 12.5mm eyepieces and actually miss the 11mm I stupidly sold a while back. I genuinely use them all, sometimes within the space of a few hours as seeing varies or the scope incrementally cools down.

[alan potts]

People talk about some of the material that TV use in the Radian EP's running out. Anyone know what is so special about this?

Has it run out or has it just become too expensive?

Alan.

[paul schofield]

I agree the 10mm Radian is an outstanding eyepiece. I also got mine used for £100 (fleabay) and it was in as new condition. The thing I like about it is the pin sharp stars, right to the edge of the fov. It is my favourite ep in my collection based on its performance. I have never tried any other TV Eyepieces but if the Radian is one of their cheaper models, I cant wait to try one of their more costly ep's, maybe a Nagler......mmm we will see.