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Old 16-11-2020, 03:55 AM
astro744
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Quote:
Originally Posted by gregbradley View Post
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.
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).
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