10mm Masuyama eyepiece

[gregbradley]

I recently got a 10mm Masuyama eyepiece and was keen to try it out. I also have a 3.5mm Nagler type 6 sitting there for a while unused I wanted to put through its paces.

Last night I setup my new to me AP130 F6.3 GT scope and a diagonal.

I tried several eyepieces. The best were the Masuyama and the 3.5 Nagler.

The Masuyama in the main centre area where you mostly look (its an 85 degree eyepiece) gave the nicest views. Sharp, good contrast. I could make out the 5th dim companion star in the Orion Trapezium despite terrible seeing.

The downside was star deformations out closer to the edge. But overall I liked this eyepiece the best.

The Nagler gave some nice views, not quite as contrasty or sharp as the Masuyama but round stars out to the edge.

Unfortunately 10mm is the shortest Masuyama currently on the market. I think a 5mm one would suit my short focal length refractors well. Its a very small and light eyepiece but only 6.5mm eye relief (I don't wear glasses ordinarily).

I think I will repeat the test tonight (its clear here) possibly with the CFF 150 F6 scope which I know is super sharp and very colour free as a comparison.

There is a 20mm Masuyama.

Perhaps I just need to mount the 10mm with a 2X barlow.

I got some nice views of Mars. The 3.5mm Nagler gave some nasty sun star type flaring occassionally.

Greg.

[Anth10]

Greg,
I concur - they are exquisite eyepieces the Masuyama’s- I have a 25mm Mas and rarely use it these days however on the occasion when I do it always provides a crystal clear view. Next in line are my 5mm and 7.5mm Takahashi’s for greater mag.

Anth

[ab1963]

Scopes of that quality deserve well corrected eyepieces that are sharp to the EOF as well as excellent contrast the Docter 12.5mm would be excellent and would definitely be razor sharp right to the field stop and cannot understand why anything less would be acceptable as sharp on axis and soft 15-20% doesn't cut it for me but that of course is only my opinion

[gregbradley]

I understand. The Masuyama's were designed at a time when most scopes had longish focal length and slow optics. Like SCTs. So they are optimised for that type of scope. I wasn't sure if F6.3 would be an issue for them or not.

I must day though the main FOV is beautiful and I tended not to be looking right out to the edge but rather moving the scope with the handset to view what I wanted.

The centre part of the view though seemed superior to the Nagler but the Nagler was good to the edge of the field so yes its the better overall corrected eyepiece. I like both.

Greg.

[Wilso]

Hi Greg,
I enjoy using the Masuama eyepieces as well. Even down to f5.3 all though not designed for these fast scopes they produce a very sharp and nice tone in the centre. I prefer them to the Tak Le eyepieces which are also are a 5 element eyepiece but produce a whiter tone and narrower field. (Still have the 5mm and 7.5mm though)
I’ve an old parks gold barlow which I found works really good with these eyepieces for magnification also, it’s a three element barlow and should correct some of the outer distortion when using them in fast scopes. I believe the Orion shorty plus is the same design.
Enjoy :thumbsup:

[gregbradley]

Good to know thanks.

Greg.

[astro744]

What were the other eyepieces in the several that you tried?

The 5th star in the Trapezium is relatively easy in that aperture even in poor seeing. The 6th is a better test for optics and mainly seeing. Increase the magnification until you see it.

The 10mm gives 82x mag. and the 3.5mm gives 235x mag. So yes there will be a difference in perceived contrast and sharpness. Compare a 9 or 11 mm Nagler with the 10mm Masuyama or better still a 10mm Delos or Ethos.

If I had an AP 130GT I would consider nothing less than something from the Tele Vue range probably Ethos, Delos or DeLite depending on apparent field and eye relief preferences (all relatively new designs) or Nagler and Panoptic (mainly Nagler as it covers full range of focal lengths in the relatively wide 82 deg. apparent field).

[gregbradley]

Nagler 3.5 type 6, Nagler 9mm type 1, a cheap Meade 32mm Plossl mainly to help find Mars. I also have a UO 12.5mm which is quite good.

Greg.

[Slawomir]

Thank you for your report Greg. Looks like those new Masuyama's are nice eyepieces. Glad you enjoy the views through the new fine glass. How did the new eypiece work with the 105mm CFF?

[gregbradley]

I haven't tried it yet. It took a bit to mount the 130 on top of the RHA and then balance it all up.

But I will.

Greg.

[Don Pensack]

Docter became Noblex, and Noblex declared bankruptcy and closed.
Any stock in Europe is gone from all providers and this is true of the US as well.
There is no point any more in recommending the 12.5mm Docter/Noblex unless you think there might be one on the used market.

[ab1963]

That's a shame and thanks for the heads up was wanting another one for binoviewing down the track looks like that's not going to happen

[gregbradley]

You might keep an eye out for one on Astromart. I did a search there and one came up in the past.

Greg.