BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

Reply to thread

Message: <blockquote data-quote="Chosun Juan" data-source="post: 3534356" data-attributes="member: 92780">David,I know what you're saying, I just think that allowing the marketers to get away with listing "available ER" would be more wishy washy than just sticking to a precise uniformly measured ISO standard (with tighter +/- 0.5mm tolerance). Let's face it, with all the recent marketing mumbo jumbo and flat out bunkum surrounding the introduction of the Zeiss SF, and Leica NV, they hardly have a stellar record. I have the feeling that give them an inch and they'd take a mile .... (hahaha, I just remembered I had an overly PC Marketing Manager once who tried to tell me about 'going the extra kilometre' ... After I'd stopped laughing, I had to explain to him that even in this metric country, we would still be going the extra 'mile' <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" />   :-OThere's too much wiggle room for variation in the available ER depending on what bespectacled cranioform template is used. We will all need different available (or effective) ER depending on all of those facial characteristics, spectacle script and design, ocular and eye cup dimensions and design, that we've mentioned, and the interplay between them all. Granted we are only talking about several mm, but such a system would be open to abuse from less scrupulous sellers.Even if a standardized facial/glasses template was used industry wide, people at the extremes of the distribution curve may find little correlation with that for them.Anyway, I just think having 50 million (or thereabouts! <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" /> different ER figures put forward from the marketers is less than desireable. I am coming at this from the point of view of a full time spectacles wearer, but I imagine non-spectacle wearers would be just as interested in an eye cup extension range.I also think that a heck of a lot of the 'ease of view' (or not) that we all experience (and endlessly discuss! <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile    :)" loading="lazy" data-shortname=":)" /> is tied closely to ER, physical fit, our own facial/spectacle characteristics, the bins design (such as the increased randpupille of the SV's for example), and the myriad way this all combines together. It could also go some way to accounting for differences in CA and edge performance etc seen in the same bin by different users.Chosun  :gh:</blockquote>

Verification