1390 replies to this topic

[Alan S]

 

A TPL actual use thread might be a good idea 

I asked for this back in post #318 on July 28th….but there is apparently more interest in things unrelated to these new eyepieces…

 

An actual use thread is still needed.

[JeremySh]

Yup… a typical CN eyepiece thread- we’re havin’ a ball! 

 

Speaking’ of which- Was out last nite engaging in a bit of Luna-see, this time using my f/12 MK-67, to observe Luna emerging from our neighbor’s tree, and before / into its occultation by his roof. Luna peek-a-boo  I’m truly fortunate in that the previous owner of this optically sweet Russian- built Orion-marketed Intes MakCass equipped it with a Moonlite focuser enabling good focus to be achieved quickly & effortlessly!

 

Herein ran quite a few EPs, one of which was- YES, the new Tak 12.5mm TPL, selected specifically for its 1.04mm exit.pupil in this OTA! 144X native gave very sharp & detailed Lunar views. A critical test for EPs in this arena I find to be sunlit-shiny lunar peaks just off the terminator in the shadow region… they can present as “double stars”. If the EP used cannot focus these tightly, but instead smear them thru astigmatism or other imperfection, it can be maddeningly obvious!  The TPL turned out, surprise!, to be a stellar performer in this regard, revealing a curved arc of three tightly focused  distinct points of light! These points remained distinct tho saw a tad of defocus as Luna slid off toward the field edge. So whatever degree of less-than-perfect EoF performance of this TPL, it was by no means a deal-breaker in my book… I’m lovin’ this EP!  
 

Now, one odd effect I DID note with this TPL was a weird Panoptic-type of image deformation seen at some angles as the Lunar limb extended to and beyond the FoV, kind of a parabolic stretching? This indicates to me some type of designed distortion… I’ll submit this to the experts for labeling. It was odd, but in no way distracting… I just thot it weird, and worth noting for the sake of discussion…

Firstly, thank you for bringing the thread back on topic (I note the ball folk have their own thread going, so not sure why they continue here).

 

Secondly, what you describe, if it is the same as with the Pan 24, which I avoid for the Moon for that very reason, is rectilinear distortion (RD).

[Mike B]

Hmmmm… rectilinear distortion? Sounds kinda like a personal issue.. TMI? 

 

But seriously, thanks for providing the clinical title for that! Yeah, it squashes planets into footballs toward field edges… will see how this works out with the Jovian system. 

[Starman1]

Hmmmm… rectilinear distortion? Sounds kinda like a personal issue.. TMI? 

 

But seriously, thanks for providing the clinical title for that! Yeah, it squashes planets into footballs toward field edges… will see how this works out with the Jovian system. 

Rectilinear distortion comes in two forms: positive (pincushion) and negative (barrel)

It is a radial distortion, stretching or compressing along radial lines--the wider the field, the higher the % of distortion.

Orthoscopic eyepieces are free of rectilinear distortion and, so, are 42° and smaller in apparent field.

Eyepieces larger in apparent field will have some RD.

 

Pincushion stretches the radial image:  straight lines crossing the field change shape from ) to | to (

Barrel distortion compresses the image: straight lines crossing the field change shape from ( to | to )

 

Illustrations:

https://www.research...fig10_287533399

https://learnopencv....ens-distortion/

 

When RD is suppressed, there remains uncorrected angular Magnification Distortion, or AMD.

This form of distortion can also be positive or negative.

It causes objects to grow or shrink as they near the edge of the field, like A A A A A   or A A A A A

If strong enough to see, it causes the field to look like it's passing over a ball or globe, hence the name "rolling ball" or "globe" distortion.

 

Most astronomical eyepieces minimize AMD, which means RD is left in, which causes wide fields to have high % of this distortion.

Most observers find this preferable to high amounts of AMD.

Here is a description of how each distortion affects a round image:

https://www.cloudyni...like/?p=5428080

Note: Distortion is distortion.  Both RD and AMD distortion the round shape of the moon as it nears the edge.

[TG]

Looks like discussion of the new Tak TPLs petered out a while ago. Apparently we’ve moved onto balls

Let's not hijack this thread to discuss ball eyepieces. Some activity has picked up again on my old thread so we can use that instead:

https://www.cloudyni...e-vs-pentax-xo/

[Mike B]

As a follow-on, I went Luuny again last nite, gathering more EP impressions as I enjoyed surveying the amazing Lunarscape 

16mm Masuyama-85*

15mm Celestron (vintage) Ultima Axiom-70*

13mm DeLite (62*)

12.5mm Tak TPL (48*)

13 & 7mm T6 Naglers

 

Tried to position Luna in each EP so as to exhibit the RD I’d noted earlier. Most prominent was the 13T6… I didn’t notice it as so obvious in its 7mm brother, but that might’ve been due to the magnification factor?

 

Oddly, the two widefield-Plossl types exhibited very little RD! The DeLite did, tho, commensurate with its less-wide AFoV. The TPL showed much less RD than its first impression, but it was definitely there. If indeed it is a Plossl derivative, perhaps it’s RD is Tak’s manner of mitigating the EoF effects they describe in their TPL notes? Whatever the case, it was certainly not obtrusive… the TPL is a fine window on Luna!

 

Other things noted: One thing that really jumped out at my eye was the tone of the Lunar views in each EP! The Masuyama & Ultima-Axiom were both quite white & cool. The Naglers were both busy brewing Lunar coffee  Not my cup of tea. They were certainly sharp edge to edge, and delightfully parfocal, which was truly handy! The 7mm in an f/12 MakCass was definitely pushing the exit.pupil, so less-bright, but Luna took on an orangey tone… at first I wrote this off to magnification. But then I thot to try the TPL.. it was cool & white in its Lunar perspective. Then I 2X Barlowed it (~6mm), anticipating orange juice with my coffee. Nope, was certainly a duskier view, but of a white Lunarscape! I’m liking this TPL!  
 

Honorable mentioning:

1) The Masuyama-85’s take some heat for their “pushed” optical design- an 85* AFoV 5-element? Ya gotta be kidding me!- that’s heretical. Well, much like the bumblebee whose engineering specs & aerodynamics should not allow it to fly, but it does anyway ‘cuz no one told it otherwise the Masuyama’s get flak I suspect mainly from the f/6 crowd… but stick it in an f/12 scope & watch it fly!  And it does so magnificently!

2) The TV DeLite is an impressive optical package! It views cool to my eye, sharp as a tack, & presents like a finely-crafted Japanese made Plossl on steroids! A lot to like in this EP beyond the obvious & oft’ touted! Paul D. left us all with a tremendous blessing! 

3) my closing finale last nite was to reach for my beloved Swarovski 9.2-18.4mm zoomski. Having been caught up in the fascination / pursuit of the best optical zing for my eyes & tastes in the ubiquitous fixed FL realm (dare we admit to ourselves it’s a fetish?), my best zoom had been overlooked. After giving it a run on Luna, I nearly slapped myself for being such a knucklehead! Jeepers, this EP is sharp! Nearly 60* at the 18mm end, it takes in a lot of real estate at 100X! Cool, too, by my reckoning… then dialing smoothly down to 9mm it quickly widens out to nearly 80*… a (very) slight touch on focus & there’s sharp Lunarscape EVERYwhere!  And even at 200X / 0.75mm exit.pupil it’s still TPL white & cool of tone, no orange juice! I’d have been super-tempted to throw my 1.6X Barcon into the mix, as the Swaro seemed to still have throttle to go, but it wasn’t handy. Besides, I’m getting away from long, bulky stacks in my scopes’ focuser…. 

My other cherished zoomer is a Nikon MCII, 7-21mm, so a bit more legs there, but not quite so eyeglass friendly, nor very wide for windows. Nonetheless, with a couple of zoomers like these in one’s case, and who needs fixed glass?

 

&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&

 

Not waiting for the imminent roof Lunar occultation, I staggered in at the end of my session, & joyously noticed I had a clean visual shot at Jupiter between some burly yard trees, so am hoping a subsequent TPL retort may include its use therewith?

[Scott99]

a couple nights of clear, dry weather is finally on the horizon here, first time in 3 months.  Unfortunately it's almost perfectly in sync with the full Moon, but I will get some L&P in with these. 

 

Those 16mm and 10mm Masuyamas are interesting Mike, I think I may be trying them with my f/9 scope soon.  I know I already like the magnificent 32mm at f/9.  This line represents what I would use as an "Ethos".  A Masuyama mated to an Astro-Physics barlow.  Probably the same weight as Ethos or lighter, with the option to use as a stand-alone 5 element eyepiece as well

 

I'm all about the Ohi factory these days - premium high-contast optics and smooth barrels

Edited by Scott99, 28 August 2023 - 02:57 PM.

[Mike B]

Hey-JAH!!

 

I even enjoy my 16 & 20mm Masuyama’s at f/6, no flinching! I just train my eye’s focus / attention on the central ~70* of the view, where they are magnificent! I s’pect their amazing transparency & throughput maximizes what a smallish ‘fractor can glimpse! Plus the 16 handily Barlow’s into a killer ~8mm 85* that sees an f/~12 lightcone  And smooth barrels….Oh, yeah baby 

Edited by Mike B, 28 August 2023 - 03:20 PM.

[jrazz]

a couple nights of clear, dry weather is finally on the horizon here, first time in 3 months.  Unfortunately it's almost perfectly in sync with the full Moon, but I will get some L&P in with these. 

 

Those 16mm and 10mm Masuyamas are interesting Mike, I think I may be trying them with my f/9 scope soon.  I know I already like the magnificent 32mm at f/9.  This line represents what I would use as an "Ethos".  A Masuyama mated to an Astro-Physics barlow.  Probably the same weight as Ethos or lighter, with the option to use as a stand-alone 5 element eyepiece as well

 

I'm all about the Ohi factory these days - premium high-contast optics and smooth barrels

Oh yes... exactly.

[Scott99]

 

 

Plus the 16 handily Barlow’s into a killer ~8mm 85* that sees an f/~12 lightcone  And smooth barrels….Oh, yeah baby 

Yes!   I've got the 1.7x and 2.0x AP Barlows sitting in the case for posterity, never use them, I could easily cook up a couple Ethos out of the Masuyamas - I think you said you had the 20mm too?  How does that work compared to the shorter ones?  Have you barlowed it?
 

Edited by Scott99, 28 August 2023 - 03:32 PM.

[Scott99]

Oh yes... exactly.

highly recommend trying one of the Masuyamas - either the 35mm-60mm 52 degree ones, perfect for low power w/ the TOA130, or the 85-degree ones.  Just the engraving job alone is to-die-for - it sounds silly but the quality of the build blows me away. 

 

I'm not alone in this, I just read an old thread here by BillP saying he thinks the new Masuyamas are the best-looking eyepieces ever!  and he wrote the book on it 

Edited by Scott99, 28 August 2023 - 03:34 PM.

[jrazz]

Who sells Masuyamas anyway?

[Scott99]

It's Astro-Hutech in the USA - they have the full selection of current Masu's.  And I see that Kyoie has them, but they don't stock all of them.  I think Hutech is the only seller in the US, there could be more in Japan.

 

https://astrohutech....epieces-1-25-2/

 

https://astrohutech....ma-eyepieces-2/

 

It's a little tricky - they all have 5 lens elements.  the 35mm-60mm are basically the same optics as Takahashi LE"s - 52 degree field, good edge sharpness at f/7-f/8, similar to a Plossl but a little wider. 

 

The 32mm to 10mm's are a different design, 5 elements but 85 degree field.  They rock at long f-ratios, not so much at shorter ones where the edges are pretty out of control.  But when I had an f/9 FC100-DL I liked the 32mm, it has the maximum FOV for a 2-inch eyepiece.  I think I"m going to get it again now that I have an f/9 scope.  

 

It's much lighter than the XW40mm I use as a finder eyepiece and also has the smooth barrel which is good because the finder eyepiece gets dropped in & out of the diagonal for every object and the smooth barrel doesn't catch

Edited by Scott99, 28 August 2023 - 03:50 PM.

[Mike B]

Yes!   I've got the 1.7x and 2.0x AP Barlows sitting in the case for posterity, never use them, I could easily cook up a couple Ethos out of the Masuyamas - I think you said you had the 20mm too?  How does that work compared to the shorter ones?  Have you barlowed it?
 

The 20M is fantastic in both the f/6 80mm & f/12 Mak. Its 2” size enables one to crawl inside the glass space-bubble & zowie- you are there! In the stars! Assisting this effect for *me* is folding down the soft, supple eyecup enables me eyeglasses full-access! Alas, I have not (yet?) tried Barlowing it (for the reasons mentioned).

 

Would try the 10mm, but the spec’d 6.5mm ER is intimidating. But I DO have my eye on the 26M! 

[Scott99]

 

 

Would try the 10mm, but the spec’d 6.5mm ER is intimidating. But I DO have my eye on the 26M! 

Don't worry - you can buy my 10mm for 30% off when I'm done trying it   I'm a glutton for punishment.  I"m hoping the 32mm would stave off any urges to buy the 20mm or 26mm....

 

You'd love the 32mm in your Mak!  It really is a beauty.  I also LOVED the 50mm...couldn't justify keeping it w/ my 45mm Clave, which I like for its lighter weight.  2-inch TPL's would compete with these, will be interesting to see what they do with expanding the TPL line.
 

Edited by Scott99, 28 August 2023 - 03:59 PM.

[Mike B]

Deal! Just gimme a holler when ya had enough… it’ll be my turn with

 

 

You'd love the 32mm in your Mak!  It really is a beauty.

Little doubt…. But I wanna keep my Masu’s ambidextrous for the f/6.25 peepscope, so the 26M’s exit is better.

It might knock loose my 30UFF? But I still enjoy a tightly corrected field now & then… just to say I did it. 

Edited by Mike B, 28 August 2023 - 04:06 PM.

[jrazz]

Aaaaay dunno...

 

TOA130/Masuyama 45mm: FOV of 2.37° with a magnification of 22x and an exit pupil of 5.85mm

TOA130/Masuyama 40mm: FOV of 2.12° with a magnification of 25x and an exit pupil of 5.2mm

TOA130/Masuyama 35mm: FOV of 1.86° with a magnification of 28.5x and an exit pupil of 4.55mm

 

...

 

 

BT100XL/TPL 25mm: FOV of 2.14° with a magnification of 22x and an exit pupil of 4.29mm (and you use both eyes)

 

Tempting... I will put it on the "thinking about it" shelf but it's prolly too much exit pupil for my LASIKed eyes. (I generally don't go above 5mm as it creates coma-like stars)

[Mike B]

 

…but it's prolly too much exit pupil for my LASIKed eyes.…

Exits are soooo key & critical for our eye’s perception! I’ve always been in amazement at the simple demo of zooming a good EP from a longer FL to shorter, and watching in real-time as the sky background darkens & small, faint fuzzies suddenly rise into visibility! Has to be seen to be believed- it’s astounding!

[Scott99]

Big exit pupil seems to bring out all the weaknesses of your eyes, I get astigmatism at 6-7mm.  Usually OK with 6mm but 5 is better.   I have fond memories of using the UO and TV 55mm Plossls in my 20's but no more.....the Clave 45mm is nice but my XW30mm isn't going anywhere  

[Thomas_M44]

The 20M is fantastic in both the f/6 80mm & f/12 Mak. Its 2” size enables one to crawl inside the glass space-bubble & zowie- you are there! In the stars! Assisting this effect for *me* is folding down the soft, supple eyecup enables me eyeglasses full-access! Alas, I have not (yet?) tried Barlowing it (for the reasons mentioned).

 

Would try the 10mm, but the spec’d 6.5mm ER is intimidating. But I DO have my eye on the 26M! 

 

Yeah, I presently have all of the 85-degree Masuyamas.

 

Frankly, the 6mm ish ER of the 10mm is just too close for comfort given my facial features. In fact, I need to get it boxed-up, as I’ve promised to send it on to BillP.

I can use my 1.6X Nikon EiC Barlow with the 16mm Masuyama (10mm ER) to achieve an effective 10mm when desired, and so the 10mm Masuyama isn’t really needed.  But, YMMV…

 

 

Deal! Just gimme a holler when ya had enough… it’ll be my turn with

 

Little doubt…. But I wanna keep my Masu’s ambidextrous for the f/6.25 peepscope, so the 26M’s exit is better.

It might knock loose my 30UFF? But I still enjoy a tightly corrected field now & then… just to say I did it. 

As a precaution to anyone reading this and contemplating Masuyamas: anyone who is

already a bit uncomfortable about the modest outer-field aberration levels of the TPL almost surely would be even much-less pleased with the levels of astigmatism produced in the outer-field of the 85-degree Masuyamas in scopes much faster than f/10. 
 

Granted, the on-axis is so stunningly beautiful that *many* forgive the outer-field performance at modest/fast f-ratios, and I think this is valid, but I fully understand the perspective of someone with a scope below f/8 or so wanting to be able to utilize the Masuyamas sans Barlow/amplifier at it’s full FL and thereby being dissatisfied.

 

The 2-inch 85-degree Masuyamas are stunning in essentially all scopes at medium and higher powers when used with a 2-inch Powermate, but I absolutely understand that not everyone wants to go that route.

 

85-degree Masuyamas when used without Barlows/amplifiers in scopes much faster than f/10, and particularly in scopes faster than f/8 —they are simply not a caveat-free equivalent replacement for the clean full-FOV views of eyepieces such as Naglers. 

 

 

Aaaaay dunno...

 

TOA130/Masuyama 45mm: FOV of 2.37° with a magnification of 22x and an exit pupil of 5.85mm

TOA130/Masuyama 40mm: FOV of 2.12° with a magnification of 25x and an exit pupil of 5.2mm

TOA130/Masuyama 35mm: FOV of 1.86° with a magnification of 28.5x and an exit pupil of 4.55mm

 

...

 

 

BT100XL/TPL 25mm: FOV of 2.14° with a magnification of 22x and an exit pupil of 4.29mm (and you use both eyes)

 

Tempting... I will put it on the "thinking about it" shelf but it's prolly too much exit pupil for my LASIKed eyes. (I generally don't go above 5mm as it creates coma-like stars)

Suggestion:

 

Perhaps try-out  the $250 USD 16mm Masuyama first?  
 

Are you okay with 10mm ER? 

Granted, not much shorter FL than the 18mm TPL.

 

The 16mm IMO would be very interesting in comparison against the TPL’s, and could let you know if the specific presentation and performance qualities of the Masuyamas fit usefully with your viewing preferences and needs.

 

FYI: Current AUD to USD currency conversion shows below listed price as being = $233 USD. Not sure how much shipping would be:

 

 https://www.astrodog...-eyepiece-copy/

 

Correction/EDIT:

 

I *believe* I was mistaken about the prices at Astrodog.

 

It would seem the Astrodog prices are shown in US Dollars directly, and *not* in Australian Dollars (AUD). In which case the price for a Masuyama 16mm eyepiece would be $363.59 USD —Ouch!

 

Not *entirely* certain of the above however, and so Astrodog should be contacted to be sure of the actual price.

Edited by Thomas_M44, 29 August 2023 - 02:40 AM.

[Starman1]

It's Astro-Hutech in the USA - they have the full selection of current Masu's.  And I see that Kyoie has them, but they don't stock all of them.  I think Hutech is the only seller in the US, there could be more in Japan.

 

https://astrohutech....epieces-1-25-2/

 

https://astrohutech....ma-eyepieces-2/

 

It's a little tricky - they all have 5 lens elements.  the 35mm-60mm are basically the same optics as Takahashi LE"s - 52 degree field, good edge sharpness at f/7-f/8, similar to a Plossl but a little wider. 

 

The 32mm to 10mm's are a different design, 5 elements but 85 degree field.  They rock at long f-ratios, not so much at shorter ones where the edges are pretty out of control.  But when I had an f/9 FC100-DL I liked the 32mm, it has the maximum FOV for a 2-inch eyepiece.  I think I"m going to get it again now that I have an f/9 scope.  

 

It's much lighter than the XW40mm I use as a finder eyepiece and also has the smooth barrel which is good because the finder eyepiece gets dropped in & out of the diagonal for every object and the smooth barrel doesn't catch

Also Agena Astro.

[BRCoz]

+1

 

I'm old enough to remember those Snells.  They were special; I had a pair.  My tastes drifted west coast sound tuning and I chased Infinity.

 

Yes, good speakers and good eyepieces. 

In the 70s it was Altec Lansing model 9 and then the 90s Carvin model  942.  Not good to have these in the same room with astro equipment.

 

I have not tried any of these new eyepieces yet.  I do have a Takahashi LE-50 I used a few times.

Might have to give one a try.

[Thomas_M44]

Also Agena Astro.

Agena Astro is where I bought all of my 85-degree Masuyamas.

 

 Unfortunately, They presently show *all* Masuyama eyepieces as being:

 

OUT OF STOCK
Availability: No ETA available from the manufacturer at this time

 

The 20mm and 16mm units are no longer listed at all. 

 

Astrodog in Australia appears to have inventory in stock, but I realize now the prices are shown in USD *not* AUD —and so rather exorbitant:

 

https://www.astrodog...turer/masuyama/

 

Nonetheless for any curious Takahashi TPL owners and/or Japanese optics enthusiasts, Astrodog has posted a brief historical primer on Ohi Optical, Fujiyama orthos and the Masuyamas:

 

https://www.astrodog...-and-masuyamas/

Edited by Thomas_M44, 29 August 2023 - 02:41 AM.

[jrazz]

I'll continue this on the Masuyama thread...

 

https://www.cloudyni...ma-2-eyepieces/

[jrazz]

I did a quick comparison of my Meade 4000 Super Plössl 32mm (the new one, not the old one) to the Tak TPL 25mm and no, it wasn't fair! For one thing, the Tak is heavier than the Meade by a fair margin! I was surprised. Much heftier.

 

I just randomly pointed the TOA to a nice region of the sky in Cygnus and looked. Wow what a difference. I guess not all Plössls are created equal. There really is no comparison. The TPL simply outperformed the poor $40 Plössl in every aspect. Sharpness, contrast, focus snap. 

 

I think this drives home how much of a different type of eyepieces these are even though they are both called "Plössls". 

 

TBH the TPLs and TOEs have now taken over all eyepiece duties in everything that can take an eyepiece. I now prefer them to the EOP 100°.  On the TOE there is simply no better contrast combination and on the BT the views of the moon are incredible. I really should learn some selenography now that it's actually interesting to me.

 

BTW, the TPL do provide a more enjoyable look than the TOEs. It's not a fair comparison as the focal lengths are so different but I find myself leaving the TPL 12.5 in even when the TOE's would be a better fit. I was able to split the Double Doubles at 80x with the TOA and the TPL 12.5.

 

I have a 7.5LE coming so I'll compare that as well...