While skimming the early reactions to the new Powershot announcements, one of the first I came across remarked that Canon had completely failed to meet the large sensor compact challenge being issued by Micro Four Thirds and the upcoming Samsung hybrid system. Why put a small sensor in there when Sigma, Olympus, and Panasonic have shown that one can simply stick a large sensor in there?

As readers of this site already know, camera design is a matter of picking a set of compromises.

If you have held an E-P1 with the kit zoom lens mounted, you know that it is functionally closer to a small DSLR in size and feel than it is to a compact like the Panasonic LX3 or the upcoming S90. Zoom range, lens speed, and sensor size each come with increasing camera size.

In fact on the surface, Canon has chosen to sacrifice very little with the S90.

Let's start with the sensor. Canon claims that "Canon’s new Dual Anti-Noise System combines a high sensitivity 10.0 Megapixel image sensor with Canon’s enhanced DIGIC 4 image processing technology to increase image quality and greatly improve noise performance by up to 2 stops (compared to PowerShot G10)". If true, that will be quite a feat, as the G10 had excellent performance in the signal to noise department. My own tests put the G10 just barely behind the LX3 in this respect. Two stops of improvement would bring the sensor noise performance within a stop or so of the best Four Thirds performance.

Yet Canon has a poor track record in this area, having made a similar claim with the EOS 50D compared to the EOS 40D. After all, it's easy to improve JPEG noise performance without improving sensor signal to noise at all. Even one stop of real progress is very unlikely. That said, the S90 is most likely using Sony's new ICX685CQZ sensor, regarding which Sony has written "In the luminance signal, it features a signal-to-noise ratio improved by about one f stop over current devices."

Camera sensor technology surely has progressed more quickly than lens optical design. How does the S90 lens compare to other recent cameras?

With the S90, Canon matched the lens speed of the LX3 at the wide end, albeit with less wide angle range (28mm vs 24mm equivalent), and offers more telephoto range than the LX3 (105mm vs 60mm equivalent) at the expense of telephoto lens speed. Overall, the Canon has a 3.75x zoom with a physical aperture range of 3mm (wide) - 4.6mm (tele), and the Panasonic has a 2.5x zoom with an aperture range of 2.6mm (wide) - 4.6mm (tele). Compared to the GRD III lens, the S90 lens offers similar speed at the wide end plus a zoom range the Ricoh lacks. Compared to the GX200, the Canon doesn't go as wide but offers both more speed and a greater zoom range.

Given those basic parameters of zoom range and physical aperture range, I'd expect the S90 lens to be roughly the same size as the LX3 lens. The LX3 lens itself seemed to be a marvel of engineering when one compared its size to fast zooms of Powershot G6 era. No miracle, Panasonic shrank the fast LX3 lens by taking advantage of software to fix pronounced barrel distortion. Now Canon has created a similarly specified lens with a slimmer profile, dropping the great majority of the LX3 lens "hump". At what price?