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="FrankD" data-source="post: 2316800" data-attributes="member: 18544">LS,I didn't go back and read the thread you linked to but will do so shortly. However, judging by what you posted I think I know what you are referring to. Tunnel vision/eye relief issues sounds like it makes the most sense. Some binoculars don't have enough eye relief for some users so they end up with tunnel vision...even with the eyecups fully collapsed. In order to see the full field of view and actually experience all a binocular has to offer there needs to be enough eye relief for you to be able to see the field stop (the edge of the image where it goes from what you are viewing to the "black circle" that surrounds it).The interesting part that you brought up is the Meopta Meostar and and issue that I personally run into with eye relief and binoculars. I don't wear glasses but I do require binoculars that have a larger than average amount of eye relief because of the shape of my face. I have a high and wide bridged nose plus my eyes are set relatively close together. Full-sized binoculars with average sized eyepiece/eyecup diameters don't pose a problem for me as long as eye relief is in the 16-17 mm range or greater. If the binoculars' eyecups are wider then I need more eye relief to be able to see the full field of view and avoid tunnel vision. Some binoculars, like the Meopta Meostar 8x32, have narrower eyecup diameters so the eyecups actually fit past my nose and into my eye sockets. This happens often for me with smaller objective models (28 mm and under) so even if they have short eye relief I can still see the full field of view because the eyecups fit past my nose and closer to me eyes.David,I understand what you are saying and agree with you. Those are the best terms that I could come up with...at least for the moment...to attempt to describe what I was referring to in a useful manner. If anyone else has suggestions as to different layman's terms to describe each of those experiences then please suggest it. I am sure someone could come up with some just as descriptive but more specific to each of these experiences.I do like, and agree with, your suggestion of practical performance. I had wrestled with suggesting something along those lines as well but just couldn't come up with something that specifically described what I wanted it to. Practical performance sounds great as it does factor in such issues as eye relief, focusing speed and tension, etc... These are mechanical/design issues but they do play a part in a binoculars optical performance for many users.Ed,I was hoping you would chime in because, as I referenced in my original post, this topic is as much about perception as it is physical reality. Recognizing that one enjoys a binoculars view is one thing but being able to sit back and describe why they enjoy the view in reference to other models with different performance parameters is the tricky part.I look forward to seeing your input on this when you have the chance.Pomp,That is a tough and easy question to answer. I said it is "tough" simply because my list of "favorites" is constantly evolving as I true new (or old) models with different designs.If I take those 3 (now four if we consider the suggestion of Practical performance) criteria and apply it to some of the models I currently enjoy using then it may be useful.My fascination over the last month or so has been on ultrawide angle 7x porros...typically 7x35 but also some 7x50. I will take one of them, a recently arrived Sears Discoverer 7x35 and apply it to the "equation".Object Performance:Good apparent sharpness and low levels of CA. Average brightness (compared to today's roofs and porros with modern coatings) and contrast.Field Performance:Excellent overall because of the huge 11 degree field of view. The sweet spot is only about 50-60% of the field but because the field of view is so huge you don't pick up on it in casual use. Magnification also plays a role in this since this a lower powered binocular. As a result the depth of field is very good so a great deal of the objects in the sweet spot are in focus and free of observable distortion. Great 3D effect because of the porro design.Overall Performance:This is one that does not excel in this area because it sacrifices edge performance in preference for the extremely wide field of view. I would say this is this binoculars design's weakest area. It does appear as if you are taking an unaided image and just making it larger because of the high scores in the three field performance areas but upon careful inspection (allowing your eye roam around the image) you do pick up on the edge performance issues.Practical Performance:Based on the criteria that David listed I would have to rate this model as average to below average for a few key reasons. For one it is not waterproof. Two, it is a classic porro which means that the focus stiffens in colder weather. I don't find eye relief an issue for me personally. See what I mentioned above to Looksharp. In the case of many of these classic porros you can remove the metal eycups which allows me to narrow the interpupilary distance thus giving me the advantage of the full field of view. In other words I can see the field stops despite the huge field of view. Ergonomically I enjoy the binocular as the shape of the dogleg prism housing fits my large hands very well.To offer a counterpoint comparison I would offer up the Zeiss FL 7x42...probably my favorite current "alpha" for a variety of reasons....Object Performance:Very good for a variety of reasons. The image is sharp in the sweet spot with literally no observable CA. The image is also extremely bright with a neutral color representation. Everything I put into the center of the field of view is beautiful to look at.Field Performance:Very good for a modern roof since it sports a very large 450 foot field of view plus the apparent field of view for a 7x roof is 60+ degrees. The largest I have found for any contemporary 7x roof design. The excellent depth of field because of the 7x magnification also factors into its excellent performance in this area.Overall Performance:This is a tough one to classify with this model. The astigmatism in the outer 1/3rd of the image definitely impacts its performance in this area. It is the one area that it is deficient in in my opinion. Because of that I don't think I can rate this model and configuration as anything but average at best in this area.Practical Performance:I think it performs very highly in this area. The ergonomics are not ideal but are very good for my hands. I have had no problems with the focusing speed or tension. It is waterproof and is not greatly affected by cold weather. Eye relief is good for all users.John,Sorry it took so long for me to getting around to posting it. There was a great deal I wanted to try to relate/describe and it took a bit of time for me to be able to put into words on the screen. Glad it helped you out with your binocular choices.Hopefully see you soon.</blockquote>

Verification