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Morpheus or APM


Charlie 2436

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Even with the long eye relief requirement met it seems to be EPs with wider AFOV that have more mixed opinions about glasses suitability. I guess this makes sense, after all there are similar mixed opinions about the ease of use of wide verses narrower AFOV EPs amongst non glasses wearers too?

I notice you settled on the APM UFF for your 30mm EP, Don, not the ES 82. And the Morpheus rather than the ES 92 at 17mm. Is their slightly narrower AFOV part of the reason?

Edited by globular
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22 hours ago, TheLookingGlass said:

Explore Scientific 82° 30mm  eye lens is recessed too much for use with glasses.

Not the original mushroom top version that I have.  It was also marketed as the 30mm Meade 5000 SWA and 31mm Celestron Axiom.

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Decloaked, far right (I never took a picture of it with the outer part still attached):

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The 30mm diameter eye lens is basically flush with the top of the housing.  Measured, I get 16mm of usable eye relief, which is right at the limit of eyeglass usability.  It views similarly to the NT4s which also have 30mm eye lenses and 82 degree AFOVs.

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16 hours ago, globular said:

Even with the long eye relief requirement met it seems to be EPs with wider AFOV that have more mixed opinions about glasses suitability. I guess this makes sense, after all there are similar mixed opinions about the ease of use of wide verses narrower AFOV EPs amongst non glasses wearers too?

I notice you settled on the APM UFF for your 30mm EP, Don, not the ES 82. And the Morpheus rather than the ES 92 at 17mm. Is their slightly narrower AFOV part of the reason?

No, not really.

I found the APM 30 had a "wide-enough" true field in my scope (1.2°) to be fine as a lowest-power eyepiece I don't use all that often, and found its lighter weight and smaller size than the 31mm Nagler (my other choice, at 1.3°, as I think the ES has too much astigmatism in the outer field and too much scattered light).  But the real important reason was in "presentation".  The Nagler was sharp to the edge and displayed no astigmatism, but the field appeared to be curved as if I were looking at stars on the interior surface of a bowl.  The APM was dead flat and made me think I was looking at a star map.  I really liked that presentation, so I ended up choosing it over the 31mm Nagler or the 30mm XW.  I was also impressed with the contrast.  It is truly an under-priced eyepiece (I hope Markus doesn't read that).  My most-used low power eyepiece, though, is the 22mm Nagler (83x, 0.98°), an eyepiece I mistakenly sold once, but never again.

I would gladly have picked 82-85° eyepieces over the Morpheus eyepieces in the 14mm and 17.5mm range but such eyepieces suitable for glasses don't exist.  The 17mm T4 Nagler has some optical issues I didn't like, so that wasn't an option.  The ES 92s are overly large and heavy, and require additional counterweights on my scope, and though I think they are fine eyepieces, that obese nature just ruled them out.  The 12mm was a possibility, but I own and use a superb 11mm eyepiece (the Apollo 11) that would have duplicated the 12mm ES (plus, the Apollo is a LOT lighter).  I thought the Delos, as fine as they are, are just too narrow for that scope (I use Delites in my 'frac), as are the Pentax XWs.  I prefer 80°+ if I can get it.  So the Morpheus were the closest I could get to a glasses-friendly 80° eyepiece (the 14mm tests at 78°, the 17.5mm at 74°)  with a relatively light weight, small size, and freedom from over-abundant edge of field astigmatism.  In fact, my first full night with both, I purposely used all my eyepieces and I thought the 14mm and 17.5mm Morpheus were both excellent.  The 14, especially (my wife even commented about how sharp it was, and I agreed).  Note that this is at f/5 with a Paracorr II, so really f/5.75, and there is not much field curvature when the focal length is 1826mm.  I even find the notoriously-curved field of the 14mm XW to be acceptably flat.

Still, my experience with the other focal lengths of Morpheus eyepieces is short, so I cannot give you a full rundown of optical characteristics, though I thought all of them felt pretty much the same.  I didn't use the 4.5mm extensively--just a few minutes--because the seeing didn't allow that power (406x) to be used for long, so for criticisms of that focal length, I defer to others.  The eye relief gets tighter as the focal lengths shorten, so the 9mm may be the shortest focal length glasses users will find comfortable.  

Sorry to be so long winded.  Probably TMI.

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