BST Starguider vs TV Radian

[NGC 1502]

A brief comparison between budget and premium eyepieces.

I have all focal lengths of the long discontinued TeleVue Radians apart from the 3mm. A recently acquired used BST Starguider 18mm joined  my BST 12mm. I got the BSTs to keep in the case with my Lunt H-alpha scope, this allows a quick set up to catch a break in the clouds.

Last night was clear at my location and my 10” f4.8 Dob was out for observing. It doesn’t have a coma corrector. I thought a comparison would be interesting. First I compared the 18mm BST with the 18mm Radian. Sharpness in the centre of field, no discernible difference. Off axis, the BST was noticeably less sharp getting worse towards the edges. The claimed 60 degree field of both eyepieces seems correct. The BSTs field stop was reasonably sharp but not quite matching the razor sharp Radians. Eye relief of both eyepieces fully adequate for me, I don’t wear glasses for observing. The longer 20mm ER of the Radian does allow the observer to more easily get their eye too close leading to vignetting. The shorter ER of the BST makes it a tad more difficult for that to happen. Inexperienced observers sometimes think that’s a fault, but it’s just a misunderstanding of how to use long eyerelief eyepieces. I’ve yet to use any long eye relief eyepiece from premium manufacturers that doesn’t vignette if incorrectly used. The adjustable eyeguard of the BST is in my opinion simpler and better than the clunky Instadjust. The Instadjust is easy to fix if its too loose but again in my personal opinion is a clunky solution for an adjustable eyeguard, as is the sliding eyeguard on Delos and Delite eyepieces. Of course a clunky eyeguard doesn’t mean that an eyepiece is not absolutely superb in all other ways and very definitely worth having 👍

Comparing the 12mm BST with the 12mm Radian, the comments above are the same except for one major thing. The BST almost but not quite matches the off axis sharpness of the Radian. That’s probably because the 12mm BST has extra lens elements within the chrome barrel that the 18mm BST doesn’t have.

I also tried the above with my elderly Vixen 80mm f11.4 achromat.  Many readers will know what I found. In that scope both eyepieces are excellent and there’s no reason, in my opinion, to use anything more expensive than the wonderfully inexpensive BSTs!

Ed.

 

 

 

 

[Alan White]

Interesting comparison Ed, when did the first Starguider sneak into your care?

As you say on a slower scope why spend a lot when excellence can be achieved reasonably

KR Alan

[JeremyS]

Great comparison @NGC 1502 👍🏻

[Tiny Clanger]

Always nice to have someone reassure me that I don't need to spend any more money   🙂 The BSTs will do fine for me (well, except the 25mm in an f5, 'scope ... )

[John]

Interesting report - good to know !

After reading reports like this I often consider why so many of us have cases full of premium eyepieces

I guess there must be other reasons that they appeal to us !

 

 

 

[Louis D]

Have you ever noticed SAEP (kidneybeaning) in your Radians?  It was the first thing I noticed about them viewing through a telescope in the daytime in a shop in 1998 when they were introduced.  It immediately turned me off to them, and I went with Pentax XLs instead which display no SAEP to my eye.

[jetstream]

16 minutes ago, John said:

After reading reports like this I often consider why so many of us have cases full of premium eyepieces

I guess there must be other reasons that they appeal to us !

yes, I hope that reports like this cause massive sell offs of used premium eyepieces! (so I can buy more 😀)

[NGC 1502]

5 hours ago, Louis D said:

Have you ever noticed SAEP (kidneybeaning) in your Radians?  It was the first thing I noticed about them viewing through a telescope in the daytime in a shop in 1998 when they were introduced.  It immediately turned me off to them, and I went with Pentax XLs instead which display no SAEP to my eye.

 

 

I’ve heard several reports of eye placement problems with Radians, so accept that some have found that. But as long as the clunky eyeguard is properly deployed I don’t have any issues like that.

I’ve only ever had one Pentax eyepiece, that was the 10.5 XL, one of the range you mention. I wish I’d built up a set of them, the 65 degree apparent field doesn’t sound much more than the Radian’s 60 degrees, but it was quite noticeable to me. And the screw type eyecup a simpler and better design. When I compared the 10.5mm XL with the 10mm Radian, I found the Radian a bit sharper off axis, not a deal breaker but it was there. Overall however I rate XLs above Radians. I have looked through someone else’s 10mm XW and found it superb.

As always eyepieces are a very personal thing. I’ve had a scope since 1979, and doubt if my eyepiece journey is over…..

Ed.

 

 

[John]

20 minutes ago, NGC 1502 said:

As always eyepieces are a very personal thing.......

 

 

Ain't that the truth !

[jetstream]

17 hours ago, NGC 1502 said:

I’ve heard several reports of eye placement problems with Radians

Ive also heard the Radians are excellent, high contrast,sharp eyepieces.  Great eyepieces Ed!

[John]

I've just owned 2 Radians - a 4mm and a 3mm. This was a few years ago now. I enjoyed using them although I did find that the 4mm handling of off axis light when observing the bright lunar limb rather odd.

They were sharp, well made and comfortable to use though.

 

[NGC 1502]

16 hours ago, John said:

I've just owned 2 Radians - a 4mm and a 3mm. This was a few years ago now. I enjoyed using them although I did find that the 4mm handling of off axis light when observing the bright lunar limb rather odd.

They were sharp, well made and comfortable to use though.

 

Those of us who owned the commonly available eyepieces in the 1970s & 80s would have been astonished to have known what’s available today.  The high power eyepieces back then had virtually zero eyerelief, tiny eye lenses, and a very narrow apparent field….  Radian, DeLite, and loads more, 20mm eyerelief, 60+ degree field……..supreme luxury indeed!!

[John]

4 hours ago, NGC 1502 said:

Those of us who owned the commonly available eyepieces in the 1970s & 80s would have been astonished to have known what’s available today.  The high power eyepieces back then had virtually zero eyerelief, tiny eye lenses, and a very narrow apparent field….  Radian, DeLite, and loads more, 20mm eyerelief, 60+ degree field……..supreme luxury indeed!!

These were my 1st half-decent eyepieces - .965 inch and I was very proud of them in the 1980's. Unitron's and Vixen's

 

Edited August 13, 2021 by John

[wookie1965]

I love the BST'S I have 3 25mm 15mm and 8mm I sold my 12mm and 5mm and dropped and smashed my 18mm, as I have a 11mm Televue plossl which is very good I won't replace the 12mm. For some reason I just did not get on with the 5mm I could never get my eye in the right place I use a 6mm TMB  now. 

The one I would replace is the 18mm I did have a 20mm Televue plossl I regret selling that I should of kept hold of it. 

For me the 15mm is outstanding its my goto eyepiece. 

Edited August 14, 2021 by wookie1965

[Alan White]

On 13/08/2021 at 12:27, John said:

These were my 1st half-decent eyepieces - .965 inch and I was very proud of them in the 1980's. Unitron's and Vixen's

 

I have the same Vixens as those John

 

[Alan White]

On 14/08/2021 at 10:58, wookie1965 said:

I did have a 20mm Televue plossl I regret selling that I should of kept hold of it. 

I did the same, first TV I owned was a 20mm plossl and it was a sweet eyepiece, stupidly sold to raise funds

 

[John]

10 hours ago, Alan White said:

I did the same, first TV I owned was a 20mm plossl and it was a sweet eyepiece, stupidly sold to raise funds

 

The 1st good quality 1.25 inch eyepieces that I bought were 3 of the "smooth side" TV plossls that I purchased new in a sale from Sherwoods in Birmingham. I went for the 7.4mm, 13mm and 21mm.

I stupidly part-exchanged them at Telescope House for some new Meade SWA 4000 eyepieces (doh ! ) then realised, to late, that the TV plossls were somewhat better optical performers and spent a year or so finding them again on the used market. Lesson learned !

TH got the best of that deal !

 

Edited August 19, 2021 by John

[Louis D]

44 minutes ago, John said:

I stupidly part-exchanged them at Telescope House for some new Meade SWA 4000 eyepieces (doh ! ) then realised, to late, that the TV plossls were somewhat better optical performers and spent a year or so finding them again on the used market. Lesson learned !

At first I thought you had exchanged them for Meade 4000 Plossl smoothies, which being 5 element, Kowa made, are still sought after today.

[John]

50 minutes ago, Louis D said:

At first I thought you had exchanged them for Meade 4000 Plossl smoothies, which being 5 element, Kowa made, are still sought after today.

No, my exchange was for the Meade 4000 SWA, Japan made but with rubber eye cups.

Back then they were expensive eyepieces here so I thought that getting a couple of them in exchange for 3 TV plossls plus some cash was a decent deal. The 4000 SWA's were not well edge corrected though - I was really disappointed in them. Those plus some poor examples of Meade 4000 plossls of the same vintage (again the Japan made ones but with rubber eye cups) that I acquired put me off Meade eyepieces more or less for good

I have to be honest and say that I have not "sought after" anything with the Meade branding for many years now. My only remaining Meade item is a Japanese 4000 series UHC type filter in the 1.25 inch fitting which does seem to work well enough for what it cost (not a lot !).

 

 

Edited August 19, 2021 by John

[Louis D]

I think my only vintage Meade eyepiece is the 14mm 4000 UWA smoothie.  It's pretty well corrected for a nearly 40 year old design.  However, stray light control is abysmal.  It's definitely not a lunar or solar observing eyepiece.  I picked it up for under $100 due to cosmetic flaws.  I just wanted to see if it was really "all that".

I also have some more modern Meade gear.  Two sets of Meade RGB interference filters (one set picked up on clearance for $20 or $30 and another set packaged with a used filter wheel deal) and the 40mm 5000 SWA.  The filters have so much higher transmittance than dyed filters that it's remarkable.  The 40mm is really a JOC/ES 40mm 68 degree SWA that I picked up during the great Meade fire sale around 2013 for $125 new.  I compared it directly against my new 40mm Pentax XW-R, and found that the Meade was slightly sharper at the edge and flatter of field.  However, the Pentax is a bit sharper in the center and has little to no SAEP issues.  It's also so much lighter.  I haven't yet decided which to be on the A-team going forward.

I would like to pick up a Meade 56mm 4000 Plossl smoothie some day.  Bill Paolini liked it better than the Tele Vue 55mm Plossl in his comparison piece 12 years ago.  That, and it is super cool looking to me with its classic lines.  It might be useful in my 127 Mak for exit pupil reasons as well.

[andre2]

The 15 mm starguider Seems a nice eyepiece for a Lunt 60 solar telescope To start with think! ( 20 and 15 mm)  (A bigger image then 12 mm has no much sense I think.) staying with the 15 focal range, there is also an 15 mm TV delite. I also believe  that the image through this 15 delite eyepiece is also a little bigger then the 15 starguider ( 14.2mm vs 15 mm? based on a "Test" with TV plossl vs normal plossl)   , so maybe this 15 mm delite would be a nice  "best one"  ( image quality and size wise)  together with a simple 20 plossl for a normal Lunt 60 tilt..?) thanks for the tip.

 

 

Edited September 29, 2022 by andre2

[andre2]

• Update: Hi, i think I find  my own ideal answer: "don't pay  €250 more for just a little better image quality and just a little bigger image, except when You have enough money" .  Thanks.

Edited September 29, 2022 by andre2

[Coco]

I love the BST 12mm in my cheapo achro's,  Bresser 127L & Celestron 102 SLT, the other night I sat on a tall wooden stool looking at the trapezium in Orion through the Bresser 1200L &12mm BST, four pin sharp points surrounded by pale green looking nebulosity and Orion hadn’t even fully risen, wonderful!

[RT65CB-SWL]

I do have not have any BST Starguider e/p's, though I have looked through a few in the past. For those on a budget I recommend them.

That said, I could not resist to add my TeleVue e/p list below, sung to the tune of 'The twelve Days of Christmas'...

Three TeleVue Plossl's
Two TeleVue Radian's
Two TeleVue Nagler's
and a TeleVue Nagler zoom!

😅😂

...and today is the twelfth day/end of Twelvetide and the start of Epiphany/Epiphanytide.

😉😆

[NGC 1502]

16 hours ago, Philip R said:

Three TeleVue Plossl's
Two TeleVue Radian's
Two TeleVue Nagler's
and a TeleVue Nagler zoom!

😅😂

Pic required to add to your poetry attempt😊

Looks like the Poet Laureate will be out of a job soon😁