High-end Scopes Roundup

Comparisons on resolution, image quality, value, and more

For this review, we surveyed an even dozen full-sized birding scopes, sent to us by manufacturers as their top-of-the-line scopes. All were full-sized scopes, with objective lenses between 77mm and 88mm, and all were of the angled eyepiece design. They all came with zoom eyepieces: 10 scopes with the usual 20-60x zoom and two—the Leica and Swarovski—with new, wide-angle, 25-50x zoom designs. All were waterproof, and all had fully multi-coated optics and special glass to minimize chromatic aberration.

We had the scopes for more than a month, enough time to become quite familiar with them and to test and retest under varying conditions. We also invited a team of Iowa bird watchers, who were delighted at the opportunity to compare the best of the best, to come for a test day to assist in the evaluations.

Perusing the prices, you may catch yourself blinking. Can you now really spend $4,000 on a spotting scope? Indeed you can, and more than half of those in our survey cost more than $2,000. The range of prices in the 12 scopes is from $575 to $3,995. Here's how we tested, which scopes got the top scores, and why.

Best Resolution

A primary consideration of a scope is its resolution, the ability to show fine detail. We tested all the scopes for resolution at a mid-range distance of 25 yards. We set the eyepieces to the highest power they all had in common, which was 50x. Our target was a standard United States Air Force resolution chart. We then mapped the observed relative scores to a scale in which the top score was 5.

For scopes that got similar scores, we went further. We put a booster on the eyepieces and compared them at double magnification, at 100x. Only then could we see any differences in resolution among some of the top scopes. As another test, we placed a one-dollar bill next to the chart so we could compare text, graphics, and fine engraving details.

The Kowa Prominar 883 stood out. Each time we tested, the Kowa's better resolution was clearly visible even without a booster. It quickly became our reference scope, the one we kept going back to while testing, to rule out inconsistency due to eye fatigue or the effect of changing light conditions. If the Kowa's score stayed the same, we knew we could trust our eyes.

The Kowa's larger 88mm objective lens undoubtedly contributed to its high resolution score. The laws of optics say a bigger lens theoretically can resolve finer detail. Another factor may be the pure fluorite crystal element in the objective lens, which largely eliminates chromatic aberration. It is not a coating, and it is not fluoride ions in the glass. The lens element is made from industrially grown fluorite crystal.

It's worth noting that the five next-highest scopes—Zeiss, Leica, Swarovski, Vortex, and the 77mm Kowa—scored so closely to each other that it required 100x magnification to rank them. We believe that the resolution differences between these scopes would not often be discernible in the field. The chart is arranged in order by resolution score, with the highest at the top. It's important to note that the lower-priced scopes at the bottom of the chart do not have poor resolution. They do a fine job for their price range, although they suffer from competing against the best, most expensive optics in the world.

Best Overall Image Quality

Overall image quality, although it includes resolution, is more a holistic and subjective evaluation of the viewer's experience. Multiple factors interact. So we were especially interested in including the guest judges' opinions.

We asked our judges to consider sharpness, contrast, brightness, field of view, color fidelity, and freedom from chromatic aberration. But ultimately they were trying to determine which images looked best to them overall. The score for each scope is the average of all the judges' ratings.

The new Leica 8 2mm APO Televid got the top score, closely followed by the Swarovski and the Kowa 88mm. Here's an experience we had that may illuminate why this was the case.

One day we watched an eastern kingbird 80 yards away in a willow tree at the edge of a pond. The kingbird repeatedly bashed a cicada against a branch, softening it up for ingestion. We looked through the 88mm Kowa, admiring the bird and even the details of the veins in the cicada's transparent wings. And then we looked through the 82mm Leica and its wide-angle zoom eyepiece. We were struck by the rich, beautiful image of the bird in its habitat, framed by willow leaves. The visual field was more completely filled and delivered a more satisfying subjective experience.

Note that the Swarovski's 25-50x wide-angle zoom gives an experience similar to the Leica's. Leica edged out the Swarovski in scoring because of its slightlywider field of viewat 50x and better eye relief.

With both of the new Leica and Swarovski eyepieces, the image circle, the picture frame, stays the same size when you zoom in or out, compared with most zooms, in which it grows and shrinks. You get better immersion in the image at all magnifications. But there is a tradeoff. With the 25-50x eyepieces you lose the 60x maximum magnification and its higher resolution.

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