Actually I think a lot of of axis problems with any binocular has a lot to do with how well the eye cups fit the face, hands, and eyes of the user. The SE is a prime example of this. Superb binocular with eye cup issues for some users. There seems to me to be some issue with comparable optical quality 8x 30-32 vs 8x 42-43 mm glass regarding eye cup extension. I had a small issue initially with the B3, but it went away when I unscrewed the eye cup assembly and put in an 0-ring to extend the eye cup a tad.
I've made a somewhat analogous mod and the Mavens are (for me) different
binoculars - Steve, thank you very much for the suggestion. If others have favorite pairs of binoculars for placement but are looking to upgrade to better optics, this might be an approach that would open up more choices.
I thought about your comment and about how I was holding the Mavens. As I'd said before, I'd been finding getting working eye placement tricky. I needed to be in a very narrow range of IPD settings and at a very specific angle to the binoculars, which I was able to accomplish by resting the oculars against my eye socket just under the eyebrow. Dropping the eyecup a stop lower produced "too close" vignetting much of the time, so I was working with the cups fully extended most of the time - and was right at the edge of "too far" vignetting.
The net result was that there was typically a gap at between my cheek and the bottom of the eyecup. That gap certainly could be a source of reflection - I had thought that it was a light pattern inside the ocular, but on close inspection, there were very similar patterns in the Monarch oculars as well.
Last night I took some measurements of the Maven oculars and the Monarch oculars:
.............................................Maven..................................Monarch
ocular glass...........................23 mm .................................24 mm
diameter
eyecup outer .........................38 mm.................................42 mm
diameter
eyecup height .......................12 mm.................................13 mm
glass to lip
Stated eye relief....................15.1 mm ..............................17.1 mm
Looking at this, it looked to me as if I should try making the Maven eyecups wider, rather than longer.
This morning, I found find some 1.5 mm rubber gasket, and tried wrapping the eyecups with that, to see if it improved eye placement.
It certainly seemed to, but I didn't want to glue the gasket into place.
I thought about your post again and realized that I didn't know how to unscrew the eyecup assembly, and was really curious about how you'd gotten the rubber eyecup covers off to put an O ring under them. I have a pair of Vanguard 10x42s that I don't like much, so I thought I'd see if I could suss out how to remove their eye cups. The first step seemed to be removing the rubber housing over the eye cups.
The rubber housings on the vanguards are not glued into place. Hey presto - I was finished for the day. I didn't need to remove the Maven eyecups, but rather could fit the Vanguard eyecup covers over the Maven covers. Doing so gives me eyecups with an outer diameter of 41 mm.
For me, in this configuration, I have more freedom with the IPD setting than with the narrower eyecup, I'm able to rest the bins on more surfaces on my face, and the off axis glare suppression is much better. I may want to add an o ring as well to get a bit more distance from the ocular to my eye, but the extra thickness helps me with more flexible (perhaps just easier to find?) eye placement.
So again, thank you. I hope others take a few minutes to look into adjusting diameter as well as eyecup height with their good but picky about placement binoculars as well.
$200 might well seem excessive, but having the option to use it to gain a field usable binocular seems like a small price to pay. Assuming it works for you.
I don't know if my enthusiasm for the modification from Maven's been clear, but for me the manufacturer-supported, extended focus is very helpful. For a few years I used microscopes professionally, and I've used binoculars mostly for pleasure (and occasionally for actual fieldwork some time ago) for many years. The folks who trained me were all advocates of viewing without eyeglasses, and the view has always been much, much better for me without them.
Once it became hard or impossible to get good binoculars that could compensate for my nearsightedness, I found it very frustrating. I persisted in slamming focusers into the end of their ranges and squinting. Once my eyes got to the point where I needed bifocal lenses, I was really frustrated because even if I chose to use the glasses, the positioning was taking much more thinking than I liked. I've considered getting RK, but a friend who's an opthalmologist thinks that for me it's a riskier procedure to the kind of eyesight I use than is worth it.
The binoculars themselves - let me elaborate a bit on what I meant when I wrote that they smoked the Monarchs (which are nice binoculars, superior in all ways to the Vanguards and very easy to use.)
It comes down to precision and crispness of focus. The Monarchs are apparently not able to focus as crisply as the Mavens. Some of that may well have a lot to do with better optics - the contrast on the Mavens is very good, and edges in foliage are very well represented, even glistening.
But the other point with the Mavens is that they're very precise. I don't often steer through focus more than once with them, where I can saw back and forth through focus with the Monarchs. Also, the Monarch diopter setting does something, but what it does varies a great deal - I find myself resetting it far more often than I need to with the Mavens. I put that down to poor precision in the mechanism and possibly also some issue in the main focuser that can make the adjustment drift. (Not from near to far, but from day to day, I'm aware that differences in near/far diopter adjustment are common, although I don't seem to need it with the Mavens.)
