I mainly use binoculars on the night sky but the weather hasn't been cooperating lately so I thought I'd do a mini daytime side-by-side comparison between my Kowa 7x35 10-deg and Nikon EII 8x30, looking at a nearby park and some buildings beyond it. I am not experienced enough with binoculars to be able to discern technical details, so I am going to just describe what I saw through my eyes in layman's terms.
In the brightness department, the Kowa lost out to the Nikon, no doubt as a result of multi-coated vs. fully multi-coated and old coatings vs. modern coatings. (My Nikon EII 8x30 was bought new late last year so should have the latest-and-greatest Nikon coatings.)
In the chromatic aberration category, which I think is more critical for daytime use than nighttime use, the Kowa pulled well ahead of the Nikon. There's very little purple fringing in the Kowa whereas in the Nikon I could readily detect purple fringing away from the center of the view. This alone makes the Kowa more comfortable than the Nikon for bright daylight viewing, though the Nikon's lighter weight is certainly an advantage when hiking.
In terms of central sharpness and edge sharpness, I am afraid I am not experienced enough to be able to properly compare the instruments for daytime use. To my eyes, both felt plenty sharp and I didn't feel that the Kowa gave up much if anything to the Nikon. I suppose that assessment of binocular central sharpness and edge sharpness is probably better done on the night sky where any defects are more easily noticed.
TFOV wise, the Kowa won though the Nikon's 8.8-deg TFOV is nothing to laugh at. Prior to the acquisition of the Kowa, the little Nikon held the title of widest-angle, glasses-OK binocular in my collection. (Note that the eye relief on the little Nikon is by no means generous, it's just that I've found a trick to make it workable with my glasses. The trick is to use super-thin double-sided 3M tape to bring the rubber eyecups as close as possible to the top of the eyepieces. I gain a hair more of eye relief this way but it's a hair more of critical eye relief that allows me to see the Nikon's full FOV with my glasses on.)
All in all, from a quick daytime comparison, the little Kowa did pretty well against the well-established, highly-regarded little Nikon. This is especially sweet considering that I paid 60 USD for the little Kowa (used obviously) and some 500 USD for the little Nikon. Now I have two little brother vs. big brother pairs that I really like: Nikon EII 8x30 vs. Nikon 18x70, and Kowa 7x35 10-deg vs. Kowa Highlander Prominar.
Who knew that the world of binoculars and binocular astronomy could be so richly diverse and wonderfully rewarding
Edited by MT4, 25 June 2021 - 08:16 PM.