Mr Yoshida's Refractor Rankings

[John]

I've recently come across this thread on the Cloudynights forum relating to comparative telescope performance rankings compiled by an amateur Japanese astronomer called Mr Yoshida:

https://www.cloudynights.com/topic/200130-2009-telescope-ranking-by-mr-yoshida/#entry2567240

I've not come across these before and wondered if anyone here knows any more ?

They certainly seem to stir up some debate amongst the "refractorholics" 

Here is a table of his more recent rankings. Some models appear more than once so I assume are different examples:

 

 

Edited October 14, 2021 by John

[markse68]

He has a lot of nice telescopes doesn’t he!

Mark

[RobertI]

Interesting John. I wonder where the Skywatcher 120ED would come on his table?

[Deadlake]

This list has been around for some time. I find that he likes the FS-128 to have similar performance to the TSA-120 interesting, however ranks the TOA-130/TMB 130 above them and the AP130EDFGT 133mm F6.3.

Surprising to see where the C11 is in the list, he has a hand picked version. Given his reference is a u300 no u210 on the list to compare with. The list is below:

101 point) Takahashi Mewlon-300 
(96 point) ASTRO-PHYSICS 160EDF * 
(95 point) Takahashi TOA-150 * 
(95 point) Takahashi Mewlon-250
(93 point) ASTRO-PHYSICS 155EDFS 
(90 point) INTES-MICRO ALTER A-608 

(90 point) ZEN250 
(88 point) CELESTRON C-11 
(88 point) Takahashi FS-152 
(88 point) INTES-MICRO ALTER-7N * 
(86 point) AOK K150/3000 Zerodur * 
(86 point) Orion 250cmF6.3 * 
(85 point) Takahashi TOA-130F * 
(84 point) TMB 130mm/F9.25-LW * 
(84 point) TEC-140 * 
(83 point) ASTOROSIB 250RC 
(76 point) AP 130EDFGT 130mmF6.3 
(75 point) TeleVue NP127 * 
(75 point) INTES MN-61 * 
(74 point) Takahashi Mewlon-180 * 
(72 point) William Optics FLT132 
(72 point) Takahashi FS-128 
(72 point) Takahashi CN212 
(70 point) TMB 115mm/F7 LW * 
(70 point) PENTAX 125SDP 
(70 point) CELESTRON C8 
(70 point) Kasai NERIUS-127EDT * 
(69 point) BORG150ED 
(68 point) William Optics10cmF8 * 
(67 point) TeleVue NP101 * 
(67 point) Takahashi TSA-102 * 
(66 point) Zeiss APQ100/640 
(66 point) TAKAHASH FSQ-106ED * 
(66 point) William Optics FLT110 
(64 point) TeleVue TV101 
(63 point) TeleVue TV102 
(63 point) Takahashi FS-102 * 
(61 point) TeleVue SDF 
(61 point) PENTAX 105SDP 
(61 point) KASAI SCHWARZ150(F8) * 
(60 point) Vixen VMC200 * 
(59 point) KASAI NERIUS-150LD * 
(58 point) Takahashi FSQ-85ED * 
(56 point) Takahashi Sky90

Following 18 scopes are loaner.
(96 point) Zeiss APQ150 
(95 point) TMB 152mm/F8-CNC-LW 
(84 point) Zeiss APQ130 
(83 point) AP SFX130EDT 130mmF7.8 
(83 point) AP 140EDF4 140mmF7.5 
(82 point) Zeiss MENISCAS180 
(80 point) Vixen VMC260L 
(77 point) Takahashiμ-210 
(75 point) INTES-MICRO ALTER-607(150mmF7) 
(73 point) INTES-MICRO ALTER-7 
(69 point) Orion OMC-140 
(69 point) Zeiss APQ100/1000 
(66 point) NIKON 10cmED 
(65 point) Takahashi FSQ-106 
(65 point) Vixen FL102 
(63 point) PENTAX 105SD 
(62 point) KOKUSAI KOHKI WHITEY DOB 15cmF8 
(57 point) TeleVue-85

Following scopes have not made into ranking list:
TMB 203 f/7
AP152 f/12 Super-Planetary 
AP152F9 * 
BORG 101ED 
BORG125ED 
BORG125 acrho * 
PENTAX-75 EDHF * 
Vixen R130 * 
Ninja400 
Ninja320 
Vixen 130mm f/7 (Ho-ta-ron, optical glass by Sumita Optics, www.sumita-opt.co.jp) 
Inamura 200mm F8 *
Dob 40cmF4.5 
SHOWA Mak 250mm
250 mm SCT 
Star Splitter Compact 4 300 mm F5.2 * 
MEADE 250 mm
TAKAHASHI FC-65 *
TAKAHASHI FC-100N 
TAKAHASHI MT-200 
TeleVue NP102i 
PENTAX PF-80ED 
SolarMax 60 

Binoculars:
Vixen 120mm
MIYAUCHI BS-60 * 
MIYAUCHI BJ-100iC 
MIYAUCHI BR142 (141?) 
Fujinon 25x 150MT-SX 
Kowa Highlander *
(70 point) Takahashi FS-102 TWIN+EMS

[mikeDnight]

The graph makes no sense! It appears to imply that a NP101 has a higher planetary rating than a TSA 102, and a NP127 higher than an FS128, both of which are pure Alice In Wonderland. The TSA is in a whole different league than the NP101 as a planetary scope, and the FS128 is a formidable high contrast high definition beast that would leave a NP127 panting for breath. And why are there two different points indicating the FS102? There are so many variables that have nothing to do with the telescopes objective that rating a telescope on it's planetary performance based on it's aperture,  lens type, or manufacturer is all but impossible. Personally I wouldn't give any credence to it at all. 

 

[Deadlake]

I find Eddgie commentary useful as ever:

https://www.cloudynights.com/topic/200130-2009-telescope-ranking-by-mr-yoshida/page-9#entry3085331

The different points for same model might be different scopes of the same model being tested, he had 5 TOA-130's to compare for example.

[Franklin]

Seems a bit silly to me.

They are all top-notch scopes.

What does a point on the scale represent?

[IB20]

Good to see a mirror winning…

[Highburymark]

Am I missing something? All the table above suggests is you have to buy a 6” or larger apo to get a 9/10 rating. Ratings are almost completely related to aperture. It’s meaningless.

[Deadlake]

10 minutes ago, Highburymark said:

Ratings are almost completely related to aperture

I think thats the point, on a night of good seeing aperture is king. While back on this island it's what cuts through the bad seeing that is the best.... 😀

At the 130 mm aperture I'm happy the only competitor to LZOS is the TOA-130... 😄, both apparently better then the AP....

Edited October 14, 2021 by Deadlake

[Sunshine]

I'm not just bias because of my scope but, this makes no sense at all, imagine how long it would take to carry out a meaningful test of all these scopes while keeping in mind seeing conditions, eyepieces, diagonals, focal lengths etc.

It would be a monumental undertaking.

[GavStar]

10 minutes ago, Highburymark said:

Am I missing something? All the table above suggests is you have to buy a 6” or larger apo to get a 9/10 rating. Ratings are almost completely related to aperture. It’s meaningless.

That’s works for me 😀

 

Actually my experience with a range of refractors is that aperture really is key when you get to a certain level of quality….

Edited October 14, 2021 by GavStar

[paulastro]

I'm just surprised anyone is taking it seriously  and/or getting hot under the collar about it.  If it was a book it would be filed under the fiction section 😁.

[Andrew_B]

32 minutes ago, IB20 said:

Good to see a mirror winning…

Aperture seems to be the biggest factor, which is one way of looking at it and you'd expect a mirror to win in that context. Mind you, the lack of anything over 300mm is a bit peculiar given the high end nature of much of the gear on the list, so wouldn't something like a relatively ordinary 400mm Dob utterly dominate purely on the basis of aperture?

I'm a bit confused as to the purpose of the list. Am I supposed to learn which scopes are best at any given aperture or is it telling me that all things being equal aperture is king (which seems a bit obvious)?

[Andrew_B]

11 minutes ago, paulastro said:

I'm just surprised anyone is taking it seriously  and/or getting hot under the collar about it.  If it was a book it would be filed under the fiction section 😁.

Not just fiction but in the fantasy section.

Anything like this is little more than personal opinion and a bit pointless unless there's some explanation of the strengths and weaknesses of different scopes and why they received a particular score.

[Deadlake]

17 minutes ago, GavStar said:

Actually my experience with a range of refractors is that aperture really is key when you get to a certain level of quality…

So on planets I’d imagine your EdgeHD 11 would be better then all your APO’s or does seeing get in the way? 😃

[johninderby]

So aperture wins, what a surprise.

[Deadlake]

3 minutes ago, Andrew_B said:

Not just fiction but in the fantasy section.

Anything like this is little more than personal opinion and a bit pointless unless there's some explanation of the strengths and weaknesses of different scopes and why they received a particular score.

It’s a score made up of multiple observers. How the score are derived I don’t know…

[GavStar]

2 minutes ago, Deadlake said:

So on planets I’d imagine your EdgeHD 11 would be better then all your APO’s or does seeing get in the way? 😃

Interestingly not, for planetary I much prefer my bigger refractors to my c11, the views are crisper. Maybe seeing (or lack of it) is a factor.

[Andrew_B]

1 minute ago, Deadlake said:

It’s a score made up of multiple observers. How the score are derived I don’t know…

If it's based on the quality of the view through the eyepiece then that's fair enough but I don't think anyone would be surprised that more aperture tends to be better, and that high quality kit scores better than lower quality at the same aperture.

In other news, the Pope is suspected of being Catholic. 

[Louis D]

I look at it this way.  If you've got $10,000 to spend toward getting the best planetary views, a decent sized Dob with a Zambuto mirror will blow the doors off a similarly priced APO and quality mount on most nights here in Texas.  Perhaps things are different in the UK, but I've always been underwhelmed by the planetary views through high end APOs when compared to the views through high end Dobs of similar money at star parties here.  We are generally pretty far south of the jet stream, though.

[dan_adi]

My 8 inch apo is not on the list. Guess I should get rid of it 😂

[ScouseSpaceCadet]

14 hours ago, paulastro said:

I'm just surprised anyone is taking it seriously  and/or getting hot under the collar about it.  If it was a book it would be filed under the fiction section 😁.

Maybe the leak of this chart is a cunning plan by unknown dark forces to sow discontent amongst the better off refractor owning community? Is Mr Yoshida really Trevor Slattery ?!

[mikeDnight]

To accurately assess or compare planetary performance between scopes, the scopes would need to be literally side by side, with top class seeing, using the same eyepiece design giving the same magnification, and on the same night. Seeing can differ greatly even over just a few metres at the same site as I've found many times. Then of course there's the visual acuity of the observer, as we don't all see the same level of detail, even among observers having many years of experience at the eyepiece. The great W. F. Denning summed things up perfectly when he stated "What one man sees through a 5 inch glass, another man needs a 10 inch". (Telescopic Work for Starlight Evenings).  

[Andrew_B]

16 hours ago, Louis D said:

I look at it this way.  If you've got $10,000 to spend toward getting the best planetary views, a decent sized Dob with a Zambuto mirror will blow the doors off a similarly priced APO and quality mount on most nights here in Texas.  Perhaps things are different in the UK, but I've always been underwhelmed by the planetary views through high end APOs when compared to the views through high end Dobs of similar money at star parties here.  We are generally pretty far south of the jet stream, though.

I think you'd struggle to get the best out of a big scope of any kind here in the UK compared to many places in the US. I've also read that obstructed optics tend to be more affected by poor seeing, then there's factors like temperature and weather changes that can favour doublets over triplets and Newtonians over SCTs simply because they reach peak performance so much quicker even if another design might be better when both are acclimatised.

6 hours ago, dan_adi said:

My 8 inch apo is not on the list. Guess I should get rid of it 😂

I have some bad news, it's total junk.

Good news is I'll take it off your hands for proper disposal and because I'm such a generous person I won't even charge you for shipping! 😂