125 replies to this topic

[dufay]

Just stumbled across this new eyepiece line due for release in two weeks' time (in time for the Mars opposition). I can't recall it being mentioned here before.

 

http://www.vixen.co..../at/acc/hr.html

 

 

Focal lengths are 1.6mm, 2mm and 2.4mm, all 42° AFOV and with 10mm ER.  It seems to be a five element design. 

[junomike]

Interesting and useful for those with short F/L telescopes.

 

Mike

[Max Power]

Hi-grade kellners?  This could be the best thing since TMB monos.

 

28,000 yen= $250 each, HHHHHHuuuuummmmm.

Edited by Max Power, 27 February 2016 - 01:02 PM.

[dufay]

Maybe one could see them as "extensions" to the Takahashi Hi-LE line, with which they share some similarities (although this new line seems to be a 3 element + smyth as opposed to the HI-LE's abbe+smyth). The HI-LEs retails at about ¥ 33.000, so the price is pretty comparable. It is evident that Vixen wants to market this as a high end eyepiece line. Will be interesting to hear the verdict of the early adopters.

[fmasa]

HR Eyepiece is 3 group 5 element. The person in charge of Vixen said "something like Konig". I guess Konig (2 group 3 element) and smythe lens are used. Furthermore, I heard that made several trial product. Possibly a long focus may be added in near future.

[fmasa]

HR eyepieces pictures

Attached Thumbnails

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[junomike]

The Field Stop is very "Pentax XO" like!

 

Mike

[Scanning4Comets]

Ummm.....No thanks!

 

[junomike]

Oh, you know you want the 1.6X to view upcoming Mars @ 800X......

 

Mike

[ewave]

Now we're talkin about the real soda straw effect...

[AnakChan]

I saw those in CP+ 2016 in Yokohama yesterday. Didn't bother paying too much attention to them since I don't do much plantery (which was what they were for - I think the Vixen rep was saying in prep for Mars opposition in May). Just peering through the 1.6mm did look pretty dark.

 

 

Attached Thumbnails

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[CHASLX200]

I would love these if they were 60 degree FOV with 18mm ER. 

[Scanning4Comets]

Oh, you know you want the 1.6X to view upcoming Mars @ 800X......

 

Mike

 

You know who would LOOOOVE that ep for his views at 1,500x

 

Edited by Scanning4Comets, 27 February 2016 - 07:12 PM.

[MortonH]

With such short focal lengths, who are these aimed at?  Most Tak or Vixen scopes are f/8 or thereabouts and I imagine these are what many Japanese amateurs own.

[AnakChan]

With such short focal lengths, who are these aimed at?  Most Tak or Vixen scopes are f/8 or thereabouts and I imagine these are what many Japanese amateurs own.

The sample graphs provided on @dufay's link used the AX103S & R200SS as their OTAs when testing (compared to their LV/PLs) :-

 

X-axis View angle/Apparent field of view (half angle)

Y-axis - Strehl

 

[BillP]

Very odd as they mention in the marketing how the magnification is so low using a 10mm eyepiece in the Vixen 81S Apo, which has a FL of approx. 624mm.  But using the HR 2.4mm in that scope yields 260x and .3mm exit pupil!!  I mean this will work ok in good seeing if observing the Moon...but that is way too dim for a planet.  I am wondering what they are thinking with this line. 

 

If they had a 3mm I would go for that as that is workable in short 80mm scopes.  But 2.4mm and shorter is beyond extreme. 

 

Curious.

[MortonH]

 

With such short focal lengths, who are these aimed at?  Most Tak or Vixen scopes are f/8 or thereabouts and I imagine these are what many Japanese amateurs own.

The sample graphs provided on @dufay's link used the AX103S & R200SS as their OTAs when testing (compared to their LV/PLs) :-

 

X-axis View angle/Apparent field of view (half angle)

Y-axis - Strehl

 

 

 

Thanks.  I didn't read far enough down the page!

 

In my 200mm f/5 Newtonian the 2.4mm would give me 417x magnification, which is way too high.  However, two years ago Mars and Saturn were high in the sky here and I routinely pushed 250x and occasionally 333x with a 3mm eyepiece.

 

If they made one of these in the 3-3.5mm range I might be interested.

[BillP]

Interesting in the chart that they chose the HR 1.6mm when they have the 2.4mm and it would have been a direct compare to the 2.5mm LV.  So are the 2.0 and 2.4 not so hot?

[Max Power]

I frequently max out my Nagler 2-4 zoom in 8" f/5 and small refractors.

Seeing is good along the I-10 corridor, will be first in line to try these.

[CHASLX200]

Very odd as they mention in the marketing how the magnification is so low using a 10mm eyepiece in the Vixen 81S Apo, which has a FL of approx. 624mm.  But using the HR 2.4mm in that scope yields 260x and .3mm exit pupil!!  I mean this will work ok in good seeing if observing the Moon...but that is way too dim for a planet.  I am wondering what they are thinking with this line. 

 

If they had a 3mm I would go for that as that is workable in short 80mm scopes.  But 2.4mm and shorter is beyond extreme. 

 

Curious.

There was one nite i used a Vixen LV 2.5mm and a barlow with a 14.5" Starmaster and would have loved one of the 1.6mm or 2mm eyepices.  That was my best all time nite as there was no seeing and jupiter at 1150x+ was dead still and i ran out of power to go higher and i sure could have gone higher .  I think a nite like that comes once in a lifetime.

Edited by CHASLX200, 28 February 2016 - 12:32 PM.

[Lew Zealand]

I used to use a 2.5mm BO/TMB on planets all the time in my 100mm f/6 so I can see a use for the 2.4 if it has improved resolution or contrast but since replacing that with a 2-4mm Nagler Zoom, I haven't found the 2mm end of the NZ to be useful yet.  Mars is quite good at 2.5mm in my 127 f/7.5 but nothing else can tolerate that small of an exit pupil.  And of course the atmosphere needs to cooperate which, for instance, it wasn't doing last night even at 4mm in the shorter focal length 100mm f/6.

 

A problem for us Northern Hemisphere viewers during the closer Mars oppositions is that it is placed lower in the sky in the South.  We lose on atmospheric effects as we gain in apparent size, making the use case for 1.6 and 2.0mm less compelling.  Oh well, time to move to Oz.

 

Another thought about assessments of "resolution" in very short focal lengths like these Vixen HRs:  There are no telescopes which are delivering an image of such resolution that the optics of the ~2mm eyepiece need to be perfect.  If there is no more resolution to be revealed at the eyepiece beyond about a 2mm (or maybe 1.5mm for the eagle-eyed) exit pupil, then any EP delivering a smaller exit pupil need not *necessarily* deliver a perfect Airy disk.  Yes, I know that all aberrations are cumulative so a lower quality EP will add a bit of blur to the now already diffraction-limited image of multiple overlapping Airy disks, and an EP with background reflection/elevated brightness problems will mar contrast of the image (eg: my BO/TMB 2.5 on the Moon).  However, when going down to an 0.5mm or smaller exit pupil, just how much difference can there be between, say:

 

2.5mm BO/TMB

2-4 Nagler Zoom @2.5

2.5mm Nagler T6

2.58mm Pentax XO

2.4mm Vixen HR

5x barlowed 12.4mm Meade 4000 Plossl??

 

It's less than a 1mm exit pupil on the shortest focal ratio of scopes, how much more damage to the view can one of these do vs. the others on planets?

[BillP]

 

There was one nite i used a Vixen LV 2.5mm and a barlow with a 14.5" Starmaster and would have loved one of the 1.6mm or 2mm eyepices.  That was my best all time nite as there was no seeing and jupiter at 1150x+ was dead still and i ran out of power to go higher and i sure could have gone higher .  I think a nite like that comes once in a lifetime.

 

 

And when you do experience these evenings, you realize that the atmosphere is the only real limiter and that one can have an enjoyable, productive, and aesthetic view far beyond 100x/inch.  What you describe has happened to me 3 times now...all on different planets on different evenings over the too many years...Jupiter, then Saturn, then Mars.  The Mars one was crazy too as I was at over 550x in my little TSA-102 and the image would just not get anything other than etched and detailed.

[macdonjh]

 

 

There was one nite i used a Vixen LV 2.5mm and a barlow with a 14.5" Starmaster and would have loved one of the 1.6mm or 2mm eyepices.  That was my best all time nite as there was no seeing and jupiter at 1150x+ was dead still and i ran out of power to go higher and i sure could have gone higher .  I think a nite like that comes once in a lifetime.

 

 

And when you do experience these evenings, you realize that the atmosphere is the only real limiter and that one can have an enjoyable, productive, and aesthetic view far beyond 100x/inch.  What you describe has happened to me 3 times now...all on different planets on different evenings over the too many years...Jupiter, then Saturn, then Mars.  The Mars one was crazy too as I was at over 550x in my little TSA-102 and the image would just not get anything other than etched and detailed.

 

 

It's happened to me twice: 560x with my driveway scope (200mm classical Cassegrain) on Saturn.  Once in 2014 and once last year.  I don't keep a Barlow anymore and my shortest focal length eye pieces wouldn't come to focus so I had to stop at 560x.

 

I think I'll buy the whole HR set for my new scope: 2.4mm (2188x), 2mm (2625x) and 1.6mm (3281x).  I wonder if the eye relief for these eye pieces will be so short that your eye lids will hit the eye piece when you blink?

[gene 4181]

 

 

There was one nite i used a Vixen LV 2.5mm and a barlow with a 14.5" Starmaster and would have loved one of the 1.6mm or 2mm eyepices.  That was my best all time nite as there was no seeing and jupiter at 1150x+ was dead still and i ran out of power to go higher and i sure could have gone higher .  I think a nite like that comes once in a lifetime.

 

 

And when you do experience these evenings, you realize that the atmosphere is the only real limiter and that one can have an enjoyable, productive, and aesthetic view far beyond 100x/inch.  What you describe has happened to me 3 times now...all on different planets on different evenings over the too many years...Jupiter, then Saturn, then Mars.  The Mars one was crazy too as I was at over 550x in my little TSA-102 and the image would just not get anything other than etched and detailed.

 

Over the  too many years  , interesting Bill, not the eyepiece thing as much as the rarity of these nights . I see so many  asking right now and your post  illuminates that

[Sarkikos]

Very odd as they mention in the marketing how the magnification is so low using a 10mm eyepiece in the Vixen 81S Apo, which has a FL of approx. 624mm.  But using the HR 2.4mm in that scope yields 260x and .3mm exit pupil!!  I mean this will work ok in good seeing if observing the Moon...but that is way too dim for a planet.  I am wondering what they are thinking with this line. 

 

If they had a 3mm I would go for that as that is workable in short 80mm scopes.  But 2.4mm and shorter is beyond extreme. 

 

Curious.

 

Personally, I would not use a 0.3mm exit pupil when viewing the Moon.  Too many eye floaters!   The Moon is bright enough that we don't really need to pump up the power more than a 0.8mm exit pupil to see all the detail that can be seen.  I don't need to.

 

But it would be OK for double stars during decent seeing, or maybe Mars at small apparent diameter.

 

Mike

Edited by Sarkikos, 14 March 2016 - 11:20 AM.