robert Report post Posted August 18, 2007 I've got another Bino question, and I'm suer it's been answered in some form here, but I haven't found it through searches. With the power being the same, would you go with a larger or smaller objective, for example a 42 or 56. I would think the 42s would be enough field to look around in, but if you can, why not get a larger field of view. I would think the problem with the larger field of view would be that there is too much to get your eyes around, and is there the possibility of missing something towards the edges? I would like to here if anybody has any thoughs on this, Thanks, Robert Share this post Link to post Share on other sites
Outdoor Writer Report post Posted August 18, 2007 I've got another Bino question, and I'm suer it's been answered in some form here, but I haven't found it through searches. With the power being the same, would you go with a larger or smaller objective, for example a 42 or 56. I would think the 42s would be enough field to look around in, but if you can, why not get a larger field of view. I would think the problem with the larger field of view would be that there is too much to get your eyes around, and is there the possibility of missing something towards the edges? I would like to here if anybody has any thoughs on this, Thanks, Robert Larger objective lenses also let in more light because they provide what is known as a larger "exit pupil." The exit pupil is merely the small disc of light that you see in the eyepiece when the binocs or a scope is held at arm's length. The size of the exit pupil is important because it tells you how much light is available. You can determine the size by dividing the objective lens diameter (in millimeters) by the magnification. In normal light, the human eye can only utilize an exit pupil of 2.5mm. When the light is bad, though, the eye can use up to 7mm, with an average of about 5mm. 10X binoculars or a scope with 42mm objective would have an exit pupil of 4.2; it is 5.6 for 56mm. Some companies use the term, relative brightness, rather than exit pupil to rate the brightness of scopes and binocs. In reality, it is meaningless and is nothing more than the square of the exit pupil. In other words, a scope with a 5mm exit pupil will have a relative brightness of 25. A 4mm exit pupil would be 16. For the nontechnical folks, it simply provides a comparison reference. -TONY Share this post Link to post Share on other sites
Coues 'n' Sheep Report post Posted August 18, 2007 That is a good question.... The larger the objective lens the better. Period! Example: 10x50 Swaros are WAY brighter and clearer than the 10x42's. As a matter of fact they are clearer and brighter than my Swaro 15x56's because of the higher power. Share this post Link to post Share on other sites
Outdoor Writer Report post Posted August 18, 2007 That is a good question.... The larger the objective lens the better. Period! Example: 10x50 Swaros are WAY brighter and clearer than the 10x42's. As a matter of fact they are clearer and brighter than my Swaro 15x56's because of the higher power. Not sure about the clarity factor, but if you determine the exit pupil, you'll see why the lower power is brighter. The EP is 4.2 for the 10X and 3.7 for the 15s. -TONY Share this post Link to post Share on other sites
COOSEFAN Report post Posted August 18, 2007 That is a good question.... The larger the objective lens the better. Period! Example: 10x50 Swaros are WAY brighter and clearer than the 10x42's. As a matter of fact they are clearer and brighter than my Swaro 15x56's because of the higher power. along the same lines.........The 8x50 SLC's I gave to my sister were WAY brighter than the 10x50 SLC's! The clarity of those 8x50's was insane and I could glass as though it were daylight on full moon nights with em' When I'm glassing in the evening, I will have to take the 15's off the tripod and snap on my EL 8.5's as the sun goes down. Even though my 8.5's have a smaller objective lense than the 15's......they are alot brighter in very low light. This set-up is perfect in my mind.....I've got the best of both...small bino's with a wide feild of veiw and clarity in low light, and the large bino's that'll sniff out an antler tip or an eyeball in the brush at amazing distances with incredible clarity with good light!!! The 10x50 SLC's are by and far the best all around glass though if you have to settle on one pair......but I personally would never be in the Coues woods without my 15's My $.02, JIM> Share this post Link to post Share on other sites
robert Report post Posted August 19, 2007 Thanks Tony, C 'n' S, and Jim, thats very good info, I really appreciate it! Robert Share this post Link to post Share on other sites
