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Message: <blockquote data-quote="denco@comcast.n" data-source="post: 3198858" data-attributes="member: 25300">Here is a quote from some of the threads on DOF."Unfortunately, the phrase "depth of field" has several meanings. Optically, it is strictly a monocular property, that is, it does not refer to what you see using both eyes. In that domain, as stated in the previous post, it refers to the range of acceptable focus fore and aft of an object at some distance from the observer. Hardly anyone actually means that when evaluating binoculars, because they use both eyes. The term has greatest utility when applied to photography (although not particularly stereo photography). When both eyes are used with a binocular (as should be the case), the brain fuses slightly different images from each eye, the amount of difference being determined by the separation between the objective lenses. Focused at any working distance, porro and roof binoculars each produce fused images, but the former results in spatial perception having greater depth and smaller apparent images, and the latter in spacial perception having shallower depth and larger apparent images. This is because of the way that depth cues are interpreted by the brain.In any event, when using both eyes "depth of field" primarily refers to the perception of spatial depth, which is what the observer uses to judge relative distances accurately. In this regard, Porro prism binoculars with more widely separated objectives retain a permanent advantage over roof prism designs."Say what you want about roofs having the same DOF at the same magnification as porro's but be it the 3D image or the spatial depth advantage I notice better DOF with my 8x30 EII's versus my 8x32 SV's.</blockquote>

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