30 replies to this topic

[25585]

My experience too. The 17 ES had too little spherical aberration to be a concern, whereas with the 12mm I find I have to be quite careful with eye placement. It's quite tolerable, but noticable. 

 

I don't see spherical aberration in the 22 or 31 Naglers, but then I don't wear glasses to view.

The 12 '92 does need slightly more eye placement care than the 17, but wearing glasses, its still easy enough to use, though my Noblex is the easiest of my 12mm UWA eyepieces. Morpheus, ES92, Long Perng 80 (14) and Noblex are all much much easier than any Nagler, including T4s, & I expect the Apollo is, & T7s will be.

[TayM57]

The 12 '92 does need slightly more eye placement care than the 17, but wearing glasses, its still easy enough to use, though my Noblex is the easiest of my 12mm UWA eyepieces. Morpheus, ES92, Long Perng 80 (14) and Noblex are all much much easier than any Nagler, including T4s, & I expect the Apollo is, & T7s will be.

Yeah, but it wasn't difficult to use the 12ES92 at all. The SAEP is there, but doesn't really hinder my enjoyment of the EP. 

 

It does however, make it an unsuitable EP for Lunar, but for me, 12mm is too low a power in most of my scopes to use on the moon anyway. 

 

But it does appear that you and I have different definitions of what easy constitutes as, and probably different criteria that defines easy. 

 

For me, an easy eyepiece is one that has the flattest exit pupil. Several eyepieces fall into this category, including the A11. The A11 was extremely easy. The Delites have have flat exit pupils, so they behave really well. 

 

I think for you, easy is defined as >20mm ER + no SAEP or very little of it. 

 

For me, easy is defined as flat exit pupil + no SAEP or very little of it. 

 

But I'm willing to bet that nearly all eyepieces have spherical exit pupils. It's our tolerance for it that varies from individual to individual. 

 

I cannot stand the Morphii on Lunar though. The ER is simply too long, and I suspect, the exit pupil is more spherical than I can tolerate. In contrast, the Delites are superb on the moon, despite having the same ER as the Morphii. 

[25585]

Yeah, but it wasn't difficult to use the 12ES92 at all. The SAEP is there, but doesn't really hinder my enjoyment of the EP. 

 

It does however, make it an unsuitable EP for Lunar, but for me, 12mm is too low a power in most of my scopes to use on the moon anyway. 

 

But it does appear that you and I have different definitions of what easy constitutes as, and probably different criteria that defines easy. 

 

For me, an easy eyepiece is one that has the flattest exit pupil. Several eyepieces fall into this category, including the A11. The A11 was extremely easy. The Delites have have flat exit pupils, so they behave really well. 

 

I think for you, easy is defined as >20mm ER + no SAEP or very little of it. 

 

For me, easy is defined as flat exit pupil + no SAEP or very little of it. 

 

But I'm willing to bet that nearly all eyepieces have spherical exit pupils. It's our tolerance for it that varies from individual to individual. 

 

I cannot stand the Morphii on Lunar though. The ER is simply too long, and I suspect, the exit pupil is more spherical than I can tolerate. In contrast, the Delites are superb on the moon, despite having the same ER as the Morphii. 

For me "easy" is a combination of two things, long enough eye relief, and equally or perhaps more important, easy attainable and retainable exit pupil. Delos have the first (so did Radians), but not the second, various other TVs likewise including <13mm Delites. 
 

But how do you know what shape an exit pupil is, and what makes it a particular shape? Eyepieces with flatter, or convex eye lenses are easier I find. The TV 40mm Plossl compared to their (modern) 32mm Plossl is an example. A laser or narrow beam has long reach, but has to be exact to center its target. Perhaps those optics are in part included, or excluded, from eyepiece designs, which affects their use.

 

WRT ES92s, are you sure its SAEP and not just getting too close to their eye lens? Delos have large eye lenses, but distance adjustment.

[TayM57]

But how do you know what shape an exit pupil is, and what makes it a particular shape?

 

WRT ES92s, are you sure its SAEP and not just getting too close to their eye lens? Delos have large eye lenses, but distance adjustment.

When at optimal position, there is extra sensitivity to certain parts of the FOV dimming out with very tiny movements of my head. That can be induced with any LER EP I know but you get entire blackouts of the FOV. SAEP is a little different in that specific parts of the FOV will start dimming. This is what you referred to, in your comments that the 12ES92 requires extra care in eye placement. Because it has SAEP.

 

Don says the Morphii has no SAEP but honestly, I can see it in the Morphii 9. Not sure about the other focal lengths.

[Starman1]

When at optimal position, there is extra sensitivity to certain parts of the FOV dimming out with very tiny movements of my head. That can be induced with any LER EP I know but you get entire blackouts of the FOV. SAEP is a little different in that specific parts of the FOV will start dimming. This is what you referred to, in your comments that the 12ES92 requires extra care in eye placement. Because it has SAEP.

Don says the Morphii has no SAEP but honestly, I can see it in the Morphii 9. Not sure about the other focal lengths.

The 9mm has a lot of eye relief. Even wearing glasses, I had to add an o-ring under the eyecup to yield a stable eye position.

[TayM57]

Yeah, I use my 9 with no eye cups, as I like the morphii with the thin barrels. The ER is so long, I don't have to worry about scratching my glasses. I do use them in a seated position, as I do with all of my eyepieces.