Edge sharpness in Binoculars (1 Viewer)

[Paultricounty]

For me, it depends on how fast or slow the fall off in sharpness at the edges are. If the fall off is fast, you notice it more than if it is slower and more gradual. Anymore I don't care if the edges are tack sharp like in the EL or NL, but I do like fairly sharp edges like in the Nikon HG versus the soft edges of a Leica. I would rather have a bigger FOV with fairly sharp edges than a smaller FOV with tack sharp edges because I find I can see more birds at the edge of a big FOV with fairly sharp edges and then move the bird to the center of the FOV. I miss fewer birds because of the bigger FOV. That is why I like the Nikon HG 8x42 with it's 8.3 degree FOV and fairly sharp edges better than the Swarovski EL 8.5x42 with its puny 7.6 degree FOV and tack sharp edges.

HG either not selling yet or not sold yet. 😜

 

[tenex]

Interesting observation. This is purely subjective (but would like to know if others see the same) - I have found that when birds are at closer range, the sweet spot I perceive with most binoculars also seems larger. Maybe my eyes have better accommodation at shorter range, or maybe the larger images give more visual cues, but everything is easier the closer targets are. That's part of the reason why I consider detail at distance to be the stiffest test (unfortunately, one that is also needed in a lot of my birding).

Sorry, apparently once I've examined and accepted a bin as adequately sharp, I pay no further attention to this in different situations. Which means not only that the area of full sharpness is big enough, but the falloff is modest enough not to interfere with what I need to see outside it. I generally can't even look directly near the edge of the field without blacking out, so would be relying on peripheral vision which wouldn't pick up the finest details anyway. But accommodation shouldn't be involved because the image distance doesn't vary.

 

[Pileatus]

If you are in a buying process and have found a pair of binoculars that you like for one reason or another, there's one thing to consider if you're not sure about whether the sweet spot is big enough: The closer your subject is to you, the larger the sweet spot should be. Picture a distant bird in your diagram and it will be inside the 50%-ring and perfectly sharp. Watch birds at your feeder in the garden through a 10x and you will wish for a 80 or 90% sweet spot.

One of the best posts on BF!

 

[jafritten]

One of the best posts on BF!

Thank you! I'll tell my wife. Even though she keeps saying I was cleverer than I look, she's always surprised when I seem to know something.

 

[Maljunulo]

I do believe we’ve uncovered a fundamental law of nature here.

“If it’s closer, it will look bigger.” (whether you use binoculars or not)