Beating the Nagler 31 at it's own game ?

[John]

I've just seen this eyepiece from Masuyama (Japan) with a 32mm focal length and an 85 degree AFOV. I wonder how it does in an F/5.3 dob ?:

http://www.apm-telescopes.de/en/masuyama-2-inch-eyepiece-32-mm-focal-length-85-field-of-view.html

It's not cheap but it's certainly a lot less than the Nagler 31mm.

Edit: It's a 5 element, 3 group design so might be challenged by faster scopes - maybe one for the SCT / large refractor owners ?

 

[Highburymark]

13 minutes ago, John said:

I've just seen this eyepiece from Masuyama (Japan) with a 32mm focal length and an 85 degree AFOV. I wonder how it does in an F/5.3 dob ?:

http://www.apm-telescopes.de/en/masuyama-2-inch-eyepiece-32-mm-focal-length-85-field-of-view.html

It's not cheap but it's certainly a lot less than the Nagler 31mm.

Edit: It's a 5 element, 3 group design so might be challenged by faster scopes - maybe one for the SCT / large refractor owners ?

 

Think FLO has these John - also saw them reviewed in one of the Astro magazines a couple of months ago - go down to 50/60mm for very low power views - would be interested to see if anyone's used them

[Ruud]

Oh, that's interesting!

20 mm eye relief and 450 gram. About €300 less than a Nagler.

Anyone found any reviews yet?

[rwilkey]

I have the Explore Scientific 82 degree 30mm ep, can't see that this new ep will beat the views through my ep.  Priced at £212 at FLO, the ES is also hard to beat on price as well. 

[Pig]

55 minutes ago, John said:

I wonder how it does in an F/5.3 dob ?:

There is only one way to find out John  I await your report.....

[John]

2 hours ago, Highburymark said:

Think FLO has these John - also saw them reviewed in one of the Astro magazines a couple of months ago - go down to 50/60mm for very low power views - would be interested to see if anyone's used them

You are right, FLO do have them

I didn't realise that they were carrying the Masuyama's.

 

[Ruud]

Someone measured the field stop of the 32mm Masuyama 85° as 47 mm (link), which allows this comparison to the Nagler:

This would mean the Masuyama shows less pincushion distortion than the Nagler, in spite of its wider afov.

I hope the field stop was measured correctly because an AMD as low as 1% very good for an astronomical eyepiece.

 

[michael.h.f.wilkinson]

Very interesting indeed. It could replace my LVW 42mm in terms of field stop diameter, and the 31T5 "Panzerfaust"in terms of magnification

[michael.h.f.wilkinson]

Just found this link through CN:

http://agenaastro.com/kasai-trading-extra-wide-vue-eyepiece-32mm.html

Very similar in looks and spec. The new Masuyama might not be all that new

[michael.h.f.wilkinson]

Digging deeper in the CN thread, there is a suspicion these are rebranded UO Widescans, no use below F/10:

http://www.cloudynights.com/topic/552679-new-masuyama-32mm-85-degrees-afov/

[Louis D]

CN has a user report on this eyepiece in this thread.  Seems pretty decent by all accounts.

[John]

56 minutes ago, Louis D said:

CN has a user report on this eyepiece in this thread.  Seems pretty decent by all accounts.

Interesting. If these are the same as the Widescans etc then it would not do well in a fast scope at all. I used to have one - great at F/10, loads of astigmatism at F/6.5. Trouble is, £300+ is a lot to spend to find out it's a re-hash of an older design

[Ruud]

Is the Widescan the same as this König MK 80?

       (link to source of image)

A König has five elements.

[John]

I don't know for sure but University Optics did have re-branded versions of the Widescan II eyepieces in their range so it would not surprise me if there was a continuing connection.

It's really quite a maze trying to work out who makes what with eyepieces !

 

[Putaendo Patrick]

There have been several "runs" of Masuyama eyepieces going back to the 1980s or 90s if I remember correctly. They are made by the somewhat enigmatic Ohi Optical Manufacturing Co., Ltd of Japan which also makes a line of orthos branded by Kasai Trading, University Optics, Kokusai Kohki and others. Hence the similarity to EPs sold by these brands.

Mr Masuyama was (or is) the founder of the Ohi Optical Manufacturing Co., although I believe the Masuyama eyepiece design was by his son. I've been able to try out earlier models, and they are superb although with a smaller 52 degree FOV. Top of the range (although I've never seen one) was a 4" barrel 100mm EP!

I've no idea, however, whether the latest offering are equally as good. Presumably the design is significantly different to achieve the wider FOV.

[alan potts]

As interesting as this is I think I will be sticking to my Nagler. It has to be said though when I had the 30mm UWA Meade which I also imagine goes for the ES 30mm, that fights its corner very well at a lot less money. I even remember reading a CN review where the writer preferred the Meade but being a TVaholic now I am not going back all treatment failed on me.

Alan

[michael.h.f.wilkinson]

The report on the eye lens being recessed so far that people with glasses cannot see the entire FOV is a no-no for me. Why design an EP with 20mm ER and then recess it by 5mm or more? What is the point?

[Louis D]

4 hours ago, michael.h.f.wilkinson said:

The report on the eye lens being recessed so far that people with glasses cannot see the entire FOV is a no-no for me. Why design an EP with 20mm ER and then recess it by 5mm or more? What is the point?

So people who don't wear glasses won't complain.   Unless the eyepiece has an adjustable height eyeguard, there's no pleasing everyone.

[michael.h.f.wilkinson]

1 hour ago, Louis D said:

So people who don't wear glasses won't complain.   Unless the eyepiece has an adjustable height eyeguard, there's no pleasing everyone.

I had a TMB Paragon 40mm with 20mm ER, and a nice rubber eye cup. It was near perfect in terms of comfort for both people with glasses and those without. Complete novices found it extremely easy to use. People with glasses can fold an eye cup back, and people without can fold it back up again, but you cannot remove the top of an EP with recessed eye lens (well, I can with an angle grinder, but that might have detrimental effects ). Why boast 20mm ER if in practice it is closer to 14?

[John]

22 minutes ago, michael.h.f.wilkinson said:

I had a TMB Paragon 40mm with 20mm ER, and a nice rubber eye cup. It was near perfect in terms of comfort for both people with glasses and those without. Complete novices found it extremely easy to use. People with glasses can fold an eye cup back, and people without can fold it back up again, but you cannot remove the top of an EP with recessed eye lens (well, I can with an angle grinder, but that might have detrimental effects ). Why boast 20mm ER if in practice it is closer to 14?

I agree with this. There is a dealer in the USA who quotes the actual useable eye relief alongside the manufactuers stated eye relief. There is often quite a difference !

 

 

[Louis D]

On 11/3/2016 at 11:13, John said:

I agree with this. There is a dealer in the USA who quotes the actual useable eye relief alongside the manufactuers stated eye relief. There is often quite a difference !

 

 

When measuring my own eyepieces using the reverse projection method onto a white card, I always measure usable eye relief from the top of the folded down eye guard if it is not easily removed.  If it is easy to remove (say, by simply unscrewing it rather than prying it off), I'll take a second measurement as well.  I carefully use some eyepieces in the removed state with eyeglasses that are not usable otherwise.  This is especially true for the rigid eye guards found on some eyepieces (the AT AF70 line comes to mind).