Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

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Refractordude
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Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

#1

Post by Refractordude »


Same or close to 30mm focal length. What was your findings? Thanks all
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Re: Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

#2

Post by Jones »


I've got the Celestron Edge 24mm, looks same as apm ones. The extra eye relief is great compared to Panoptic or ES 24mm's. About same performance in f4.6 scope, gets a little soft in far edges. Probable pinpoint sharp stars to edge in f5.6 or so scopes.
Arizona- where the sky's are not cloudy all night.

Triple lensed fracs are so yummy when looking at planets.
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Don Pensack United States of America
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Re: Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

#3

Post by Don Pensack »


I compared the Pentax 30mm XW, the TeleVue 31mm Nagler, the Baader Hyperion 31mm, and the APM 30mm Ultra flat field.
Field stop diameters:
APM 30---36.4mm
Pentax XW 30---36.2mm
TeleVue Nagler 31---42.0mm
Baader Hyperion 31---38.0mm

I use glasses at that focal length, so used glasses in my test.
Scope was the 12.5" f/5 dob, coma corrected to f/5.75. The field of the scope is very flat.

The Hyperion was strongly astigmatic from about the 50% point to the edge. I think this is an eyepiece for f/8 and longer.
The Pentax had good contrast, but a bit of residual astigmatism at the edge of the field.
The Nagler had the widest field but I was interested to note that, in comparison with the APM and Pentax, the field looked concave, as if all the stars were in a bowl.
I only noticed that when switching back and forth. After a few seconds, this was not seen. It was very sharp to right at the edge.
The APM struck me as having a map-flat field, which was interesting.
And the contrast was amazing. It had the darker background sky of a shorter focal length.

That flatness and superb contrast prompted me to do an analysis:
here are my notes on the 30mm APM UFF:
spherical aberration--none
inherent coma--none
astigmatism induced by the f/ratio--none
field curvature noted--none. Flattest field of all of them.
distortion type (daytime)--typical pincushion like most astronomical eyepieces--no noticeable angular magnification distortion. Excellent.
chromatic aberration--none on axis, and none lateral
eye relief--long enough for glasses when the eyecup is folded down.
light scatter control--excellent. Very slight flare from Rigel just outside the field stop. No eyepiece completely passes this test.
spherical aberration of exit pupil--none
chromatic aberration of exit pupil--none
tint (daylight use)--none
vignetting--none
thermal issues--none
field stop focus--sharp (excellent)
edge of field brightening--none
sharpness on axis--excellent
sharpness at 50% field--excellent
sharpness at the edge--excellent
apparent contrast--excellent

It was better in most parameters than the Pentax XW 30mm.
It was significantly better than the Baader 31mm Hyperion Aspheric in all parameters.
It was easier to use with glasses than the 31mm Nagler, though that is the other eyepiece I found excellent as well.
The APM is close to 1/2 the weight of the Nagler, though.

I have used the entire set of UFF eyepieces. The 30mm is the best of all of them.
Astronomer since 1963
Currently using a 12.5" dob and a 4" apo refractor
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Re: Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

#4

Post by Refractordude »


Thanks for the time Don. I really love my Celestron 30mm UFF clone. Definitely a keeper. Have you ever compared the Olivon 22mm against the Nagler 22mm type 4?
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Re: Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

#5

Post by Don Pensack »


Refractordude wrote: Sat Aug 28, 2021 3:59 pm Thanks for the time Don. I really love my Celestron 30mm UFF clone. Definitely a keeper. Have you ever compared the Olivon 22mm against the Nagler 22mm type 4?
No, I haven't. I do remember the 22mm as being much better than its price implies.
It is available under many different labels still, even though Olivon is now history.
It is a great successor to the oft-touted Vixen LVW 22mm.
It is a 2" eyepiece, though.
Labels I see still available:
Arcturus Ebony**
Astromania SWA
Omegon Redline
Skywatcher SWA**
Tecnosky SWA
Telescope Service Expanse ED
I marked with ** the 2 versions to avoid if you wear glasses because the eyecups cut off too much of the eye relief.
Astronomer since 1963
Currently using a 12.5" dob and a 4" apo refractor
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Re: Anyone Ever Compare The APM 30mm UFF Against Same Focal Length Eyepieces?

#6

Post by 25585 »


I have a Celestron Ultima LX, and TS Expanse 22mm, same optics. I also have some 22mm LVWs.

Effective eye relief is similar. On the TS, I replaced its OE eyecup with a Baader Morpheus one, both are screw in M42 thread. TS Expanse range is for afocal use as well, like Morpheus are.

The 22mm 70° do give a noticably larger view. In a 10" F5 its easy to see both M81 & M82 and some surrounding sky in the same view. 70° starts to show some coma, but my 22 LVW 65° hardly shows any, 65° to me is for F5 the limit when no correction is needed.

I use my 22/70 more than Nagler 22T4 or Orion LHD 80°. The 22/70 is very user-friendly, for me & whoever. At the magnification 22mm gives, 10° less AFOV makes less difference than higher mags would.

To start however, I use 30-something FL. Either a 35mm Panoptic, APM 30 UFF, Vixen 30 NLVW or Pentax 30mm XW. Most often the APM. 35mm Panoptic is a great eyepiece, its my one for use with OIII & UHC filters, or where I use heavier 2" eyepieces so balancing is easier when changing.
Unashamed Linda Ronstadt ♡ fan! :dance: :Clap:

Eyepieces from: Aero, Antares, APM, Baader, Brandon, Bresser, Celestron, Datysun, Docter, Explore Scientific, GSO, I R Poyser, Meade, Nikon, Orion, Pentax, Rodenstock, Siberia, Sky-Watcher, Taiso, Takahashi, TAL, Tele Vue, TS, Vernonscope, Vixen, Zeiss.

Scopes from: Altair, Bresser, Lumicon, Orion Optics UK, Sky-Watcher, Takahashi, Tele Vue, TS, Vixen.
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