Why would they need to upgrade coatings / prisms? The Zen ED2/3 is already essentially alpha level in terms of brightness/transmission and color rendition. Seems a weird thing to look for in terms of improvement. And many of the other handling or build issues were ironed out in the ED3 -- much better focus knob with a faster focus, better rubber armor, better eyecups, better QC, etc. Plus more eye relief (although tbh this seems another weird criticism, as the Zens have plenty of that... and the ED3's are even better again). And the sweet spot and glare control are also markedly improved in the ED3.
I think the big improvements that could be made in an "ED4" would only incremental, further improvements in quality control, weight reduction, etc. The coatings are the last thing that need to be improved. Optically, the only thing that could be bettered would be a reduction in pincushion and a widening of the sweet spot IMHO.
Also increasing AFOV seems another weird one to pick at. The Zens have among the widest FOV's in their class at any magnification. Getting a 7x model to have a 65° or greater would require a TFOV approaching 10°! They are already at 9°+. The 8x models with their 426' FOV are already around 65° AFOV.
Eitan, you have used ED2 / 3 somewhat interchangeably, whereas the Zen 7x36 is only available in ED2 mechanical package / optical specification, thus the various important improvements made to to ED3's (43mm size) are not available. Those improvements, while welcome, are a couple of years old, and far from the end of the story - time stands still for no man (or woman, [or even bin!]). While the Zen ED's were somewhat of a performance / value revolution, the competition has not been standing idly by. So while I agree that any improvements are going to be largely "incremental" in nature, there is hardly anything "weird" about this - in fact it's logically normal.
The opportunity for an 'ED4' was made in light of the ED2's limitations, and the context of the thread - "Why no Alpha 7x32's". Arguably a 7x36 ED4 held to ED3 pricing, and improving several critical areas would make such a 7x Alpha mid-size largely redundant, and would certainly capture a large slice of this available market segment ...... "bicycle transported - nose against shrubbery - low light - gee-whizzit chasers!" (or some such)
The ED2's had 99.5%tr optical coatings while the ED3's had 99.7%tr ones, and 2nd generation dielectric prism coatings, and the faster still 'SpeedDial2' focuser (along with the better knurled metal knob as you said). Size / tension of this mechanism was nice, along largely with smoothness, but some have found backlash (or focus slop) to be excessive, and an inherent feature of this package. This would need to be fixed for sure in any 'ED4', and there's no reason that better coatings (lenses / prisms) could not be a feature (the competitions certainly moving down that road - I wonder how much the you-beaut 64 layer CFT coatings cost?), and the coatings in the Prime HD already show better colour saturation. The little Zeiss Victory 8x32 FL is around 95% overall tr% even with its Schmidt-Pechan roof prism system, so there's plenty of room to move. I don't think there can be
too much brightness at these smaller objective sizes - Heck - I really don't think there can be too much brightness at any size!
What's really required in any 'ED4' is a lighter (and higher quality) body to bring the weight down to 20.5oz (580g) or under. A carbon-fiber-reinforced-polycarbonate body should well and truly do the trick - after all these are just for birding - not as weapons for hand to hand combat with grizzlies! Styling, rubber armouring quality (the Prime HD type is much nicer than the EDx's) and construction are also important. I would stay with the open hinge, or even high 'H' bar style.
ER, and focus speed are highly subjective (and the source of much argument / vocifery around here). For me, the 8x43 ED3's ER is still too shallow, and only the Prime HD (or near, say ~18mm) would suffice. The 7x36 ED2 worked for some glasses wearers, but not all, so improvements (increases, along with range accommodation) are needed here. An ED3 focus speed would seem ideal - though no doubt others will argue that would be too fast / slow. :eek!:
Internally there's work to be done too. I can never get within 30° of a light source before glare rears it's head in the ED3, (the Prime HD was better, and certainly showed the benefits of design work in that area), but I believe an 'ED4' could be much better still. I'm quite sure that a lot of what gets thrown around here as 'washed-out' colours is stray light and glare related. A widened sweet spot is always welcome, but the pincushion improvements should be kept to the 'circle of condition' level or slightly better - I don't think a field flattner lens assembly is required in this application, although aspheric lenses may be useful.
As far as the Fov stuff goes, the 7x36 ED2 has ~9° for 63.2°Afov. Arguably any slight increases on this are semantics. If you went to 10° fov - 176.3m@1km (529ft@1k yd) for 70° Afov then it qualifies as extra-wide-field. At a typical close-in birding distance of 10 yd say, that only amounts to the difference between a ~1.6 yd view, and a ~1.75 one, or about 1/2 a foot (or about 10%) - not much, but something. I don't think all of this is of too much consequence for the 7x.
My comments were mainly in relation to a 9x (ED2 63.4° Afov). Here there are several near extra-wide-field 10x competitors (forgetting price points for a moment), such as - Nikon 10x35 EII, and Vortex Razor HD 10x42. In order for the rationale behind the 9x to make sense, apart from the quality, it needs to be lightweight, with excellent dof, and at least 65° Afov, 126.7m / 380ft, to be a
logical competitive alternative IMHO.
Hope that wasn't too
weird, and clarifies things a bit! :t:
Who knows, as long as the focuser is cw to infinity, even LS will jump on board a 7x version (unloading the Zen 7x43 ED3 in the process - c'mon LS - you know you want to - pretty compelling arguement at 1/5th or less the price of an Ultravid HD, or EDG! That's a heck of a lot of "kippers" with the loose change!! ......)
Chosun :gh:
