Digital Camera News

Is More Zoom Always Better?

The megapixel war has paused, but the long-zoom battle is in full swing. Optical zoom is one of the last advantages that dedicated cameras can offer over smartphones, and the camera companies leverage it at every opportunity.

Most major manufacturers sell full-bodied superzooms with zoom ranges over 30x, and newer pocket-sized long-zooms are consistently hitting 20×. Panasonic and Fujifilm even have a few sub-$200 cameras with double-digit zooms.

The benefit of a huge focal range is obvious: making faraway objects appear close is awesome. It’s a must-have feature for shooting sports from up in the bleachers, or snapping candid nature shots without spooking the wildlife. Even if you don’t really need it, it can’t hurt to have it, right?

No such thing as a free lunch, friends. On the whole, longer zooms translate to softer images. We ran some numbers on all of the fixed lens cameras that we’ve tested from 2011 (and a few from 2010) and picked out a few fun facts. (How We Test)

Point-and-shoots are sharper than superzooms: On average, superzoom cameras (12x zoom or more) earned a lower overall resolution score. The drop-off was most notable among sharpness scores: P&S cameras scored a 14.11 compared to 12.81 among superzooms. Pocket cameras also earned better distortion and aberration scores.

Resolution decreases as zoom increases: Basically the same point as the paragraph above, but cameras under 10x had the best resolution scores, 10x-19x were second-best (but only by a small margin), and 20x and above show a big drop-off.

Price matters, sort of: The cameras with the best resolution scores cost between $200 and $400, but the patterns aren’t so clear. The high-end compacts over $400 show excellent scores, while the superzooms in the price range seem to drag the average down. The bottom falls out pretty quickly under $200, however. (For simplicity’s sake, we considered original MSRPs for these figures, not current street prices.)

There are some pretty clear correlations here, though it’s unwise to take these results as the gospel truth. We’ve tested all of the high-end compacts, most of the superzooms, and many of the regular point-and-shoots to come out in 2011, but these sample sizes are still too small to hold statistical significance.

Even if the samples were large enough, these results don’t accurately measure the delta (that is, how much the results actually vary). The scores we used in this comparison are our own scaled versions of raw results. (If there’s enough interest, we’ll try to crunch some numbers based on the raw data. Leave comments! Ask questions! Call us out!) Then there’s the matter of artificial pixel sharpening, which is a can of worms we won’t open here.

Let’s even cast those caveats aside—superzooms aren’t as sharp as compacts, but will amateur photographers notice the difference? Probably not. Generally, you’d have to be making large prints and looking for flaws to spot a difference. Poor noise performance is more noticeable to the naked eye, and superzooms usually outperform cheap ultracompacts in that regard.

We can’t pretend to know why exactly superzoom lenses are softer, but it certainly has something to do with moving parts. Superzooms have more motorized, shifting elements in their lenses, so there are more chances for something to go wrong in the manufacturing process, or with typical wear and tear.

We’ll put it this way: Zoom is kind of like the new megapixel. More is generally better, but too much of it can cause problems. Just remember that Galileo discovered Jupiter and four of its moons with a 30x telescope. If it was good enough for Galileo to change the course of science, a 36x camera is good enough for you.