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Thoughts on suitable 30mm ish eyepieces for f8 100/800 refractor

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With limited experience of using a ‘range’ of eyepieces compared to those who have done so over many, many  years  ( so far for me Tak and TeleVue and Leica; 4mm -25mm) I’m considering another eyepiece for my 100mm scope; the list below provide I think (corrections are welcomed) tFOV’s of 2.6 degrees to 3.4 degrees and exit pupils around 4mm, ER of 18-20. I like to stick with made in Japan/Europe and USA eyepieces where possible, but if there are thoughts on ‘other manufacturers’, feel free, as that may prove helpful to others too and give me ‘pause’ to consider them. Budget covers the Pentax and Masuyama but the Nagler may be a few £’s too much. I like to search out objects within the capability of my 100mm scope, using the very useful Interstellarum Sky Guide/ Atlas ( nothing wrong with a bit of analogue!) Skies local to me are Bortle 4, regularly Fair to Good 6-7.

Pentax XW 30-R

TeleVue Nagler 5 31mm

Masuyama 85 32mm

Thanks in advance if you’ve use(d) these EP’s and or others (oh, and to Don P. for his excellent Buyers Guide to EP’s which helped in my final selection)


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Posted (edited)

I own a Nagler 31 and I've used an XW 30. Never used a Masuyama.

If I was buying for my Tak 100mm F/9 and had to stick with Japan / Taiwan production then it would be the XW 30 because of the weight difference I think. More often with that scope I'm content with the true field that my Panoptic 24mm gives though.

For my Vixen 102mm F/6.5 I use the Nagler 31 (which is made in Taiwan) and it seems to suit that stumpier refractor.

If you can consider of production outside the areas you specify, the 30mm UFF's get lots of praise on here and other forums. This is the Stellalyra one:

StellaLyra 30mm Ultra Flat Field 2" Eyepiece | First Light Optics

Another option which will show almost as much sky is the APM XWA 20mm 100 degree but that is again made in areas outside your preferred ones.



Edited by John
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Many thanks for your comments and link John!

I’ve read reports on the Pentax XW 30-R and they are very positive; it’s good to read that you might  invest yourself given a similar consideration on production location etc. 


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The best 30mm eyepiece at the moment is the 30mm UFF. You can get it in various makes - the one I have is from StellaLyra. Pin sharp right to the edge.


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If edge correction isn't all that important to you, then the Pentax XW-R 30mm is fine.  I have the 40mm version, and it's pretty decent, but not perfect.

The various 30mm UFFs are basically flawless to the edge.

Here's a post with an image from another forum showing the difference in edge correction:


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