When I saw the press release advertising a revolutionary new “back-illuminated” sensor, my BS sensor went to red alert. First, the term is nonsense — misleading at best. Second, what could they possibly do to increase low light performance by a huge amount that nobody’s thought of already? As it turns out, camera companies are dumber than I thought (that or Sony’s BSing skill is better than I thought), because this new sensor configuration appears to be genuinely better. The main tradeoff appears to be cost, though — these cameras are expensive as hell.

Here’s the deal: sensors aren’t just magic planes of photosensitive material. They’ve got circuits on all sides, wires and transistors all over the place, and incredibly, some of it is between the lens and the sensor. I didn’t know that, but I believe it, and if it sounds a little too crazy to you, consider that your eye is organized in much the same way. There’s a bunch of junk between the iris and the light-sensitive part of the retina — so if mother nature made it upside-down, what hope did a bunch of engineers have?

So what Sony’s done, apparently, is cleared out the junk between the lens and the sensor. While I applaud them for their ingenuity (if that’s what it is), I question the benefit of it, since you’d think companies with more experience in lens and sensor design (Nikon, Canon, and Kodak, for instance) would have done something like this if it had the benefits stated. But I digress. Sony says the low-light performance is better, and they’ve actually done something to make it so, so I’ll give them the benefit of the doubt until we get some real testing done.

On to the cameras. Surprisingly, the more expensive TX1 isn’t entirely better than the WX1, just a little more futuristic. Both cameras have 10.2 megapixels, the new “Exmor R” sensor, 10FPS burst capability, built-in burst panorama (thank you), 720p mpeg-4 recording, and all the silly camera modes we’ve come to expect in consumer cameras. Pet mode, really?

Sony TX1

The sexy future-camera. 10.2 megapixels, 3″ touchscreen, optical image stabilization. Close focus down to 0.4″, which is great. 4x Zeiss zoom, no 35mm equivalent given, but it seems as if it doesn’t go quite as wide as the TX1 because its panoramas can’t be as wide. Very thin. Costs $380.

Sony WX1

The more traditional camera with similarly updated guts. 10.2 megapixels, 2.7″ LCD (not touchable), 5x zoom (24-120mm) at f/2.4, which is quite good for such a small lens. Kind of thin. $350.

So?

Both cameras will be available in September. As for which I’d get… it’s actually kind of a tough call. I’m not too familiar with Sony’s touchscreen interface but I wouldn’t assume it’s a positive. I think in the end, the WX1 is more of a sure bet even though it’s not nearly as thin as the TX1. It’s cheaper, you’ve got a really solid lens on there, and you’re not missing any features other than the touchscreen. I’m actually pleased with Sony in this case (aside from releasing their cameras in the middle of the night like everyone else and pricing them out of my range); they may actually have a superior camera technology here. But like I said before, we can’t know until some testing’s done, and I wouldn’t buy until then.