Camera lenses are getting better. Way better. And you can blame digital cameras for the improvement.
For all their advantages, digital cameras share a common problem: they tend to create images with moiré patterns and other unsightly artifacts. To eliminate these artifacts, most digital cameras come equipped with an anti-aliasing filter, which blurs the image slightly. The result is a better looking, but somewhat softer picture.
The Wikipedia article on anti-aliasing offers a simple example of what I'm talking about. Before anti-aliasing, an image might look like this:
But after anti-aliasing, it looks something like this:
Sharpening algorithms, whether implemented in PhotoShop or the camera itself, can help compensate for the loss in resolution, but not completely. The problem becomes worse if the lens isn't very sharp in the first place. Consequently, camera makers have been working very hard at boosting the resolving power of their lenses.
Case in point: Pop Photo's review of the new Canon EF 24mm f/1.4L lens. According to the review, the lens showed a "drastic improvement" over its predecessor, "especially at maximum aperture, where sharpness increased to 93.46% from 74.1% at 11x14 inches."
You can find similar improvements in lenses from other manufacturers. Even low-priced kit lenses are starting to show resolution numbers that are off the charts.
Anti-aliasing isn't the only reason camera makers are anxious to sharpen their lenses. Sensor resolution has been growing in leaps and bounds, and the new crop of 15, 21, and even 24 megapixel SLRs are quickly outstripping the resolving power of today's lenses, particularly since the bypass filter effectively reduces true lens resolution. As a result, manufacturers are playing catchup, improving lens designs and manufacturing tolerances to ensure that moving up to a higher-resolution camera also results in higher-resolution images.
Otherwise, it would be like driving a Porsche Turbo whose transmission went no higher than second gear. And what would be the fun in that?