Incoming Tak Hi-LE 3.6mm eyepiece

[F15Rules]

I've hoped one of these would pop up for a little while: I've been interested in finding a very high power eyepiece for Lunar, Planets and Double stars for my FS128 in readiness for the forthcoming season (well, it IS midsummers day, so the nights technically start to draw in now - but don't tell my wife that! ). Just this week, a pair of Tak LE's (Long Eye Relief) came up for sale, a 5mm (not of interest just because I've just bought a 5mm Pentax XW), and the 3.6mm which should fit nicely at the top end of my magnification range. Another happy coincidence is that my mix of Taks, Pentax XW and Vixen LVW are all pretty much parfocal with each other.

Tak LE's have been around for a long time, and are generally accepted as being derivatives of the original Masuyama range: and apparently, when Masuyama went bust in the late 1980s the residue of the company (and brand name) were bought by Takahashi - and the LE range appeared very soon after the demise of Masuyama, so draw your own conclusions. Other similar designs, all from Japan, included Baader Eudascopic, Parks Gold, Celestron Ultima, Orion Ultrascopic and a few others. There were definitely differences (I had pairs of Tak LE 18s and Ultimas, and the Taks definitely had a noticeably wider field of view). The only ones now left available (and not always easy to find new) are the Tak LE's and the Baader Eudascopics. It's likely most of them came out of the same factory in Japan. I believe they all have 5 elements of an Erfle type design. The Hi-LEs, however, have an extra mini barlow element at the bottom so have 6 elements whilst maintaining relatively good eye relief at high power.

I should say here, that Long Eye relief in terms of these eyepieces is a relative term: the short lengths in orthos, plossls and these Taks are never going to deliver the 20mm eye relief of Pentax, Televue and ES widefields, for example, and neither will they suit most eyeglass wearers, but, compared to orthos and plossls, the LEs do genuinely offer some eye relief benefits (see specs below). 

I've been reading with interest about the new Vixen HR range but their focal lengths are just too small, and would give too small an exit pupil for my aging eyes. But at 3.6mm this Tak should give me an exit pupil of 0.44mm, just below the 0.5mm that I'm told would be the lower limit for my age (61), and at a very comfortable (for me) eye relief of 7.5mm. That focal length of 3.6mm translates to x288, so it's not a power that I will probably be able to use as much as I would like, but my scope should be able to handle it well on nights of good seeing.. and I have certainly used BGOs in the fairly recent past at higher mags on a longer FL refractor, with good results on sensible objects.

I already have the LE 7.5mm and really like it. It is very well built, has NO undercut (a big plus IMO), and very good eye relief compared to an equivalent ortho (the 7.5mm LE has 10mm eye relief compared to 6.07mm for a BGO 7mm). The eyepiece is also very comfortable to use, much more so than using a BGO, for extended periods, and here I think the robust rubber eyecup helps, though not everyone might like it. Here are the specs for the LE 7.5mm (source, KW Telescope Canada website).

"Takahashi eyepieces have their lenses matched and assembled by hand at their plant in Japan. The lenses are all fully multi-coated for best light transmission. The LE eyepieces have a long eye relief parfocal 52 degree field of view. (unless otherwise noted) Takahashi uses ED glass for perfect color correction, making them highly prized by astronomers for planetary and lunar viewing.

Specifications:
Apparent Field of View: 52 degrees
Measured Field Stop: 8.4mm
Eye Relief: 10mm
Barrel Size 1.25 inch
Weight: 115 grams
5 Element in 3 Groups"

Now, looking at the same websites' specs for the Hi-LE 3.6mm:

"Specifications:
Apparent Field of View: 40 degrees
Measured Field Stop 7.5mm
Eye Relief 7.5mm
Barrel Size 1.25 inch
Weight: 130 grams
6 Elements in 3 groups"

Some interesting comparisons with the 4mm BGO here:

-Same fov at 40 degrees

- 6 elements in the Hi-LE vs the 4 of the BGO - so will the Tak have as good light transmission as the BGO?

-MUCH better eye relief in the Tak - 7.5mm vs 3.35mm for the BGO - that's more than double the eye relief and for me a major plus for the Tak.

- note that the eyelens is much bigger on the LEs than on BGO (and other brand) orthos, again more comfortable to use for many.

There isn't a great deal of info here in the UK on LE's but they are generally well regarded in the US, especially at the higher magnifications, rather like the Pentax XWs which do seem to be better at 10mm and lower focal lengths. I do think the new prices in the UK are silly now: the Hi LE are listed at around £350, which is £100 more than a Pentax XW, so that price must limit their appeal as a new purchase.. But at much more sensible used prices at around £90-£120 they make much more sense IMO.

I will post a report on how I find this new unit in my FS128 - once I get some sky which isn't either wobbling like a jelly or is actually reasonably dark - shouldn't be too long now for the latter!

Photo shows the actual unit I have bought, on the right. And, amazingly at the new price, Tak EPs don't come with eye caps!

Dave

[Piero]

Congratulations for your purchase!  

I had many thoughts about the Tak LE-HI 3.6mm. Here is a thread I started on CN as there are more `LE owners` over there: https://www.cloudynights.com/topic/572762-tak-hi-le-eyepiece/ . Not much information to make me press the button.. 

As you said the cost of a new one is very high, and the one you got was actually the first one I have ever seen in the s/h market (at a much more reasonable price too!). I will read your findings and opinion about this LE-HI 3.6mm with great interest for sure!  

The coming years seem promising as far as these short focal lengths concern. I am looking forward to hearing about new Vixen HR focal lengths (hopefully, finger crossed!) and the new Tak TOE which will be available soon-ish, apparently at these focal lengths: 2.5mm, 3.3mm, and 4mm (all 52deg afov, 10mm e.r., 6 elements 4 groups design). A few people on CN compared the Vixen HR 2.4mm with the Pentax XO 2.5mm. The former seemed to be right there with the latter. If it is true that Vixen bought the patent of the Pentax XO, this should not be too surprising.

I really wonder how the Tak LE-HI compares with the Tak TOE or Vixen HR..  

[John]

Interesting to hear your views on this one Dave

I've just owned one Tak LE which was the 30mm. Nice but not special IMHO.

Lets see what the Hi LE is like 

[Timebandit]

3 hours ago, F15Rules said:

   

   

   

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Some interesting comparisons with the 4mm BGO here:

-Same fov at 40 degrees

- 6 elements in the Hi-LE vs the 4 of the BGO - so will the Tak have as good light transmission as the BGO?

-MUCH better eye relief in the Tak - 7.5mm vs 3.35mm for the BGO - that's more than double the eye relief and for me a major plus for the Tak. 

 

 

Is there a Badder Genuine Ortho in 4mm ? Correct me if I am wrong but I thought the 5mm Badder Genuine Ortho was the highest magnification?

I have spent 18 months trying to get a set together?, but am I now missing a 4mm BGO and the search must restart?

As for the Tak eyepieces from what I have read the Taks never seem to of been able to gain the almost legendary status of what the Tak scopes seem to of gained. The Pentax 3.5 XW are very good it would be interesting to put one of these against the Tak to see how it performs in comparison ,considering the new costs of each. Look forward to your thoughts and results with interest .

[mikeDnight]

I've owned a few Le's and thought they were ok. I've also owned both the Hi Le's and liked them very much.

[F15Rules]

17 hours ago, Timebandit said:

 

 

Is there a Badder Genuine Ortho in 4mm ? Correct me if I am wrong but I thought the 5mm Badder Genuine Ortho was the highest magnification?

I have spent 18 months trying to get a set together?, but am I now missing a 4mm BGO and the search must restart?

As for the Tak eyepieces from what I have read the Taks never seem to of been able to gain the almost legendary status of what the Tak scopes seem to of gained. The Pentax 3.5 XW are very good it would be interesting to put one of these against the Tak to see how it performs in comparison ,considering the new costs of each. Look forward to your thoughts and results with interest .

Well, I honestly thought there was one, but now I'm not so sure.

I found this link:http://www.alpineastro.com/Eyepieces_Accessories/Genuine Ortho Eyepiece Data.pdf and that is where I took the eye relief data from. It's in the attached table below.

I haven't owned a 4mm BGO if there is one, but I know that Astro Hutech do one which ought to be identical, and the published eye relief for that one is 3.2mm, versus the 3.35mm I quoted above taken from Alpine Astro's table - so even more of an advantage in ER for the Tak.

Personally, although it might be nice to find a 4mm BGO if they do exist, for practicable purposes that eye relief figure would just be too low to use it!

BTW, I don't recall seeing a 25mm BGO either, which is on the list, although I know other brands did offer one..

Dave

 

Genuine Ortho Eyepiece Data.pdf

[John]

I've never seen a 4mm Baader GO - the 5mm is the shortest that I've used in that series.

I do have a 4mm by Fujiyama which looks just like the Baader GO's and is I guess how a Baader GO 4mm would be, if that range had included one. The optical performance is very good but finding and holding the eye lens and eye relief in the dark with my undriven scopes is, um, quite challenging !

 

[F15Rules]

On 2017-6-21 at 18:38, John said:

Interesting to hear your views on this one Dave

I've just owned one Tak LE which was the 30mm. Nice but not special IMHO.

Lets see what the Hi LE is like 

Hi John,

Yes, that's the drift I've picked up when reading about the LEs..like the Pentax XWs, the shorter focal length versions seem to be the best regarded.

My FS128 should give the Hi-LE the chance to show how good (or not) it really is. I really hope I get a chance to view Jupiter with it on a good night before it sinks down too far..?

Dave

[YKSE]

They look certainly very nice, of great build quality

I'm under impression that short focal EP pairs are more challenging than longer ones, so the smooth barrel is huge plus for mitigating addition mering difficulty.

The 2 Hi-LEs are of different optical layout than other LEs, they look like barlowed orthos to me, hence the longer ER:

Im looking forward to read your first light report.

[marcus_z]

Hi Dave,

how do you like your HI-LE 3.6 so far? I use mine with my FC-100D on the moon quite often. The views are comparable to the Takahashi Abbe line. Unfortunately, they are not exactly parfocal to the Abbes. Therefore tracking is definitely need ;-)

clear skies,

Marcus

[F15Rules]

Hi Marcus,

I haven't had a chance to use the Hi-LE properly yet, due to a combination of holiday and sky conditions.. the Jetstream plus local climate have not delivered good seeing here for over 2 months! I'm really hoping things will improve this autumn and winter?..

This eyepiece gives me c 288x in my FS128 and the one short session I had recently wouldn't support that..I got to x208 with my XW5 mm, Saturn's Cassini division was clearly visible but to be honest the sharpest view was at c x138 with my LE 7.5mm.

I think it will be another 6-8 weeks (apart from perhaps on the Moon) before my local conditions might support the almost 300x of the Hi-LE, but I knew that when I bought it.

I never thought this power level would be of much use on planets on a regular basis, I got it for the Moon and doubles mainly: I have no reason to believe it won't be excellent when conditions are right?.

Dave