转一篇尼康7X42 EDG的外国测评：
http://www.birdforum.net/showthread.php?t=116087
I had the opportunity to briefly test a prototype of the new Nikon 7x42 EDG binocular today. I didn't have time to be as careful as I would have liked and used abbreviated versions of my usual tests which included resolution and artificial star testing at boosted magnification of 56x and examination of a CA target for longitudinal CA at 56x and lateral CA at 7x. I was able to very briefly compare the EDG to a Zeiss 7x42 FL, a Leica 8x42 Ultravid (non HD) and a Nikon 8x42 LX L, looking mainly for differences in brightness, contrast and color transmission.
After just a few minutes it was clear that the EDG has MUCH higher light transmission than the LX L, and, I believe, slightly better contrast and a little more neutral color (there's just a slight hint of the usual Nikon red). Light transmission in the LX L series really needed improvement and the difference is quite obvious. The EDG appeared to be just slightly dimmer than the Zeiss FL and just a bit brighter than the Ultravid. The EDG is probably about as bright as current technology allows a complex binocular with a Schmidt-Pechan prism to be.
An artificial star test at 56x (Christmas tree ornament in sunlight) revealed a little misalignment in the left barrel (probably a side effect of collimation and pretty harmless). The right barrel was completely free of assembly defects, with just the expected aberrations. It was not the very best looking star test I've seen from a binocular, but, by binocular standards there was nothing seriously wrong either. Resolution was perfectly fine, around 3.5 arcsec in the right barrel, about what I would expect from a typical premium 42mm binocular and much better than is needed for a sharp image at 7x.
Longitudinal CA, viewed at 56x, was clearly better than the LX L. The purple fringe on the the CA target was reduced to about 1/4 the width of the fringe seen in the LX L, very similar to the Zeiss FL. The low CA makes the 56x image look quite clean and contrasty compared to most binoculars, again similar to the Zeiss FL. IMO, lateral color (the type of CA you actually see as a color fringe in binoculars at low power) is pretty bad in the LX L series and it appears to be improved in the EDG to about the level of the Zeiss FL, but all the high end roof prism binoculars have more lateral color than just about any garden variety Porro with a simple doublet objective.
There appears to me to be very little rectilinear distortion in the EDG, a design approach similar to the SE series. That's in contrast to the Zeiss FL and Leica Ultravid which employ considerable pincushion with the goal of the eliminating the "rolling ball" effect when panning. Unfortunately I didn't have time for a careful evaluation of off axis sharpness, but my brief impression was positive. I think the EDG probably uses a low astigmatism eyepiece design like the SE.
Overall, I'm quite impressed with the optics of this binocular. If production samples live up to the prototype the EDG binoculars should be perfectly capable of jostling with Leica, Swarovski and Zeiss for a seat at the head of the $2000 binocular table. |
显身卡
看来我真的需要一款42口径的顶级镜了！！
我主要是对那两块发亮的牌子很苦恼。
太形象了!
看来顶级镜不是那么好进啊