Telescope Reviews: Williams 7x50 EDs anyone?

I have Celestron 10x50 ED binoculars. It's true that CA is difficult to control completely in "fast" refractors ~ f/4 (which is what you have two of in most binoculars) using ED and other exotic glasses. Even some Zeiss FL owners have even found some CA. The 10x50 ED is slightly better at controlling CA than my other binoculars, even 8x and 7X FMC, but in extreme contrast situations (birds against clouds), a very small amount of CA can be seen on-axis, with a fair amount off-axis.

The main benefits of ED glass bins are increased color saturation and a bit more resolution compared to a comparable non-ED bin (e.g., Celestron 10x50 Ultima or Vixen 10x50 Geoma). The 10x50 EDs are only slightly behind the 10x42 SE in resolution, and those are the reference standard for 10x porro binoculars. Comparing each bin side by side, the ED is noticeably brighter (and though 42mm, the SEs have been compared to 50mm bins in brightness), and the colors are more vibrant and reveal subtle gradiations not seen in the SEs. As the CN member who did the RAF chart testing said, "it's as if the images in the SEs are washed out." Of course, the SEs deliver very nice neutral color views, only a side by side comparison can you see the difference the ED glass makes.

The ED glass makes little difference if any on globs and nebulae, which are a whitish-blue in binocualrs and can' t be resolved to a fine focus, but you can see the difference in the color of stars, and with a 7x50, you'll be looking mostly at stars.

ED glass is more important to birders since the increased color saturation can reveal subtle field markings on birds. For example, the 10x50 ED shows subtle markings on the head and throat of male Cardinals that are difficult to see with a 10x42 SE.

If you've ever used Fuji color film to take photos of fall foilage, and noitced how much more vibrant the colors look than other color film, that's the difference, the colors "jump out at you".

My main interest in the 7x50 EDs are for birding since my skies are too light polluted for a 7x50 binocular. The IF does not present much of a problem for feeder birding and the WP is a plus. If they focus like the 6x30 FMT-SX, everything beyond close focus is in focus, so they might be good for wildlife observation, though limited for birding.

7X is a bit low for distance observing. For wildlife observation, the new Minox BD 9.5 x 42 IF Magnum Binoculars with one touch focusing might be a better choice.
http://www.buytelescopes.com/product.asp?pid=9476

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Oscar Zoroaster Diggs
"O.Z."

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