Stop counting lines and just look

The reception flap over the new iPhone 4 may have obscured a different issue, namely the high-definition camera Apple built into the device.

Observers and critics are quick to point out that 720 progressive, the video resolution Apple designers selected, is already overshadowed by smaller and cheaper "video only" devices hitting 1080, such as Sony's Bloggie handheld.

Don't confuse pixel count with image quality.

In side-by-side comparisons by several web sites, the quality of video from the new iPhone beat out all the other inexpensive MP4 handhelds, with the possible exception of the Flip HD models, which equalled or slightly surpassed the iPhone camera:

What's happening here? It's subjective issues such as colorimetry, signal-to-noise, effectiveness of the automatic exposure, black level rendition, and quite a few other esoteric qualifiers. Line count, and the competitive specifications race for more lines or most pixels, is only one very small factor that human vision uses when judging that elusive "quality" factor.

Truth is, every pixel has a noise floor, and the more pixels that collectively make up the sensor area, the more the designers must deal with system noise and loss of sensitivity. That's right, for any given imager surface area, when fewer receptive "buckets" exist to gather the fixed amount of light making it to the sensor, then each bucket can collect more of the photons. Increase the number of light buckets by making each smaller, and the opportunity to collect decreases proportionally.

Back in the 1980s when CCD cameras first started penetrating the professional and broadcast marketplace, I purchase a Sony BVP-5 solid state broadcast camera. The quality of the pictures, for the time, was outstanding. But soon came the BVP-7 with a denser imager and adjustable shutter, and it forced me to upgrade. The specs on the Model 7 were much improved. Resolution charts performed better. But the images seemed, well, more "sterile" than the beloved Model 5.

Several years later, the BVP-90 came out and again I jumped. Coupled with some very expensive Canon glass, those images got me a lot of work. But often when evaluating the color monitor, I found myself wishing for the wonderful richness and pleasant detail handling of that old BVP-5 I'd started out with.

With the iPhone 4, Steve Jobs has publicly announced the Apple team took a look at all these factors when zeroing in on 720P. By concentrating on color imaging, low light performance, and a host of other considerations, the subjective quality of the images captured by the new iPhone is quite outstanding. And that's what counts.

As we used to say, "Just look at the whole frame, stop counting all those lines."

Jim Furrer