I beg to differ bh, of the pro reviews I have read, none mention a high degree of CA in the Vanguard. They either say it is low, or don't mention it at all. I notice it looks like you haven't tried the Vanguard, yourself...Are you just going by what others say, and then guessing the ED2 has less CA than the Vanguard, without directly comparing?
I also wonder why anyone would be less or more sensitive to lateral CA. It's either there, or it isn't. The only factor that allows it to be seen or not, is subject matter having edges of high contrast. Unless we are talking about red/green color blindness, in which case I could understand the CA being invisible to someone who is red/green color blind...since the CA is a yellowish-green/magenta.
JWCamp, on these 8.5x45, the outer rubber does wrap around, and that is about .08 inches wide. Then there's a groove of about .02 inches, behind it...I presume a sort of glue gap. Then there's a black ring about another .08 inches thick. It has an anodized looking finish, but with very fine, microscopic ridges in it...that aren't really "threads", but rather the way the ring is machined. This is the ring that I am referring to, which reflects so much light. It does have two tiny square "keyhole"-looking notches in the front of it, 180 degrees from each other.
Behind this, there is a much more matte looking, black ring, which extends to the edge of the objective glass element. It is wider, at about .15 inches wide. If the problematic ring in front of this one (mentioned above), was the same matte finish as this one, then there would be very little problem with "c" reflection in the view, or whatever you guys like to call it. But it isn't.
It sounds like the model you have, has the "shiny" ring perhaps smaller in size, or else maybe it is somehow behind the rubber lip a bit...I don't know. Or it could be basically identical to mine, and you're just not noticing the reflection, even though it's really not difficult to see.
Try this. Point the binoculars toward the horizon, out a large window in your house, where you can see some sky above. It will be easier if the sky is hazy, or thin clouds, and brightly diffused. Pull your eyes back from the eyepieces, and look toward the bottom of the objective lens...and see if there isn't a narrow, bright edge down there...reflecting the diffuse but bright light from the sky above. Wave your hand in front of, and above the front lenses, to see this reflection get dark. That is what I see with these, and it's coming from that machined ring which is .08 inches wide.
It could be solved by putting some kind of ultra thin, matte tape...preferably that is as matte as black felt, if not more. I'm not sure there is such a thing, but there might be. The problem would be in its thickness. If it's much thicker than paper, it will obscure some of the outer edge of the FOV. The FOV in these is already more narrow than I want.
