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Message: <blockquote data-quote="typo" data-source="post: 3189746" data-attributes="member: 83808">AdsInteresting you find the centre resolution wanting. I've tried three of the regular EDs and the apparent centre resolution was pretty good if not quite a match for the EDII which is among the best I've tested. I'd still rate the ED above average for the price. I'm not suggesting you are wrong but I wonder if your observations might tie in with other discussions I've been having recently about sharpness comparisons.I've only done detailed comparisons with the EDII, but I think it shares some characteristics with the ED. The two Vanguards seem to differ from a number of others in one aspect of perceived sharpness. They might be accused of having too much high contrast, high resolution detail for some viewing conditions. That doesn't sound like a fault, but it can be a mixed blessing.In bright conditions, when my eyes are at their best, I really appreciate how the EDII can make a view sparkle with finest detail, but in lower light levels it can look rather ordinary and others offer a bit more clarity to the view. I suspect it's related to my change in acuity in low light where the finest detail becomes a blur and reduce contrast. In photography it's well known that a lenses can be tuned for high resolution detail or for contrast where the finest detail is lost. Erich Heynacher from Zeiss demonstrated that the eye/brain favours contrast in coarse detail when judging sharpness and this is exploited in the Camera business. Unfortunately it's led to an ambiguity when we talk about binocular sharpness. Some like myself mean differences in the finest detail I can see and others how contrasty the view is for wan't of a better term. Because binoculars are effectively used so close to the diffraction limit (unlike some camera lenses) I was sceptical that there was scope for such contrast manipulation, but I'm beginning to wonder if I'm wrong. The Endeavour EDII does have the highest contrast near the diffraction limit of any binocular I've seen so far and that brings a benefit when the light is good for my eyesight.  Others with lower resolution and potentially better contrast on coarse detail do appear a little crisper to me when the light is poor. It's potentially exploitable characteristic but I really don't know if it is normally considered as part of the regular design process. We have two extremes where a binocular might be designed for high contrast at high resolution and the other low resolution but high contrast and both could be described as sharp or soft depending on the light conditions and the user's acuity. It's an unsatisfactory situation and has contributed to misunderstandings in recent discussions.I know I try to distinguish between effective resolution and contrast when commenting on binoculars when I can. When I use it I try to reserve "sharpness" for comparisons of effective resolution by eye. Others may disagree. Perhaps we need to try to find a consensus on the vocabulary used to describe effective resolution and high and low frequency contrast?David</blockquote>

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