Tele Vue Plossls and Eye Relief

[Jaxxxxx]

Hey Guys!

I went to purchase some TV Plossls today to go with my TV Barlow. The scope I will be using these with is the Skyliner 250PX Flextube however I have uncounted a small issue

I was advised that the 8mm, 11mm and 15mm would go best with this scope and my current 25mm however I just find as these eyepieces get into the lower numbers the eye relief becomes very uncomfortable.

I use the 25mm more than I should I guess as it provides me with satisfying viewing and with the 17mm of eye relief very comfortable but the smaller eyepieces this is not the case especially with the 8mm being only 6mm of eye relief.

I was considering getting the 15mm TV Plossl and perhaps spending out on a Radian for the lower number's while keeping that decent 20mm eye relief! What Radian would you suggest if I was to skip the TV 11 and 8mm?

Many Thanks

[paul mc c]

I had a 8mm TV and also found the ER a bit tight so bought a 9mm BGO and proved to be an excellent replacement,a lot more comfortable to use and IMO sharper.

Paul

[John]

The Tele Vue plossls provide the same eye relief as other plossl designs - around 80% of the focal length of the eyepiece I believe. Orthoscopics are about the same, may be a little more generous.

[Damo636]

I would probably go with the 10mm Radian giving 120x and 240x with your barlow. I am very happy with my 6mm, very comfortable with 20mm of eye relief.

[Nexus 6]

Agree with Damo here, I had two Radians before moving on to Naglers etc, they were very comfortable to use with the generous eye relief they give

Hope you acquire a couple to try out, is there no astronomy clubs close by where you could try out some of the members own eyepieces?

[rwilkey]

Hi, you'll find eye-relief specifications here, if you are not too sure:

Tele Vue Optics: Specifications

[Kef9]

I must be strange but I find that the less eye relief an eyepiece has the more comfy it is to use????

I have no problems with the TV 8mm plossl or my 5mm xo for that matter. I really like snuggling into the eyepiece but I might just be weird???

[Moonshane]

I really like the view of TV Plossls but find the eye relief even of my 15mm a little tight. OK what I really mean is that to see the whole field you have to ram your eye into the eyepiece. I find e.g. a 12.5mm BGO much more comfy than my 15mm TV plossl (and much more then my 11mm Plossl now sold).

They really are superb value for money though and of course, for higher power viewing you don't 'need' to see the whole field anyway (I just like to).

I have a 10mm and 8mm Radian too and they are also excellent as are all of these eyepieces we are talking about.

My concern with a Radian / Barlow combo is that eye relief increases with a barlow (sometimes doubling) and this might prove difficult to use. If I were you, I'd consider a 12.5mm and 9mm BGO.

One way to try out eye relief etc is to buy cheaper versions used.

E.g. you could get a used GSO 15mm plossl for about £15 and this would confirm if it's for you. Sell it on if not. You may even keep it.

You can also try the TMB clones or the BSTs which are about £30 used when they come up and these are not a million miles from a Radian.

There's always options.

[rwilkey]

Hi Kef9, nothing wrong with tight eye relief if the ep's are TV or Pentax, generally good fields of view and tak sharp. Eye relief has always been a factor with me, I like it to be just right, best 15-20mm, but this is not so important with top of the range ep's, which I can't afford, the best ones I have are the Axiom LX's, 10 ans 7mm are great, 82 degrees afov, I also have the 23mm. This is my maximum affordability range, though the XO's are within my means, but I have the Ax's now, and I am well content. I have the William Optics SPL ep's in the same range as the XO's as well.

[Adz]

I also found the Televe 8 + 11mm plossls too uncomfortable for longer period of observing. Changed to a set of BGO's and haven't looked back. I would also add that extra glass from a barlow in the optical path might not be what is wanted for teasing out detail at high power, the BGO's really do excel in this aspect. I will never sell mine!

[Kef9]

Never tried a BGO but may do one day but for a very long time my eyepiece buying days are over! Anything more is just ridiculous.

I just don't seem to have a problem with tight eyerelief. Maybe I'm just very lucky. I would just rather have the best possible view no matter how uncomfortable it is to achieve. Maybe I should get some monocentrics, nooooooooo!!!!

[John]

.... Maybe I should get some monocentrics, nooooooooo!!!!

I have the 5mm TMB Supermonocentric and the eye relief is a little longer than the 5mm Baader Genuine Ortho. Their specs are actually very similar - 4mm v's 3.9mm ER but the narrower FoV of the Supermono means the ER seems a little more generous.

Very specialised eyepiece though and won't be to everyones taste !.

A comparison with your Pentax XO would be very interesting

[rwilkey]

Hi John, I have seen the Monocentrics on the House of Optics Ltd. website but would be interested to know of the retail outlet (not planning to buy one BTW), just interested.

[John]

Hi John, I have seen the Monocentrics on the House of Optics Ltd. website but would be interested to know of the retail outlet (not planning to buy one BTW), just interested.

Hi,

Unfortunately the TMB Supermono's went out of production in 2005. They produced and sold 3,500 units I believe. It was a collaborative project from Thomas Back (TMB) and Markus Ludes (APM Telescopes). They were made by a Zeiss sub-contractor.

The retail price was around £200 each I believe although I can remember Telescope House selling off the last of their stock at a lower price than that for a short while.

[rwilkey]

Thanks John, very interesting, as I have been researching eyepiece history recently, weren't they expensive! Now replaced with the more popular ortho's.

[John]

Thanks John, very interesting, as I have been researching eyepiece history recently, weren't they expensive! Now replaced with the more popular ortho's.

I've always been fascinated by eyepieces and their history. Despite it's short production run the TMB Supermono's get mentioned a lot in discussions about top quality planetary eyepieces so I've been curious to try one for myself for some time. I did try a Zeiss Ortho once which was superb but their prices are stratospheric

The Pentax XO's that Kef9 owns are reputed to be pretty special too so that's on my "to try" list as well

Apologies to the original poster - this has gone a bit off topic

The amount of eye relief that is acceptable / comfortable does vary person to person as you can see from the responses in this thread. I've enjoyed using the TV plossls I've owned (I've had sets of both the older smooth sided ones and the newer design ones in the past) and found them very good performers on a wide range of astro objects.

If you buy used you can usually recover your costs with Tele Vue eyepieces so it's not a huge risk.

[andrew63]

This could be a consideration for you from telescope outlet - they have great deals on vixen stuff quite often. These would be in my view every bit as good as a tele vue and at this price they are unbeatable! I have used the 10mm in the older lv version and found it to be very sharp, these are reported to be even better.

Vixen NLV 12mm Eyepiece - Brand New

andrew

[Kef9]

I wish I had got into astronomy earlier when they made these special run eyepieces!

I would love to have a complete set of monocentrics and ZAOII's but second hand prices are ridiculous.

Oh well