For a true pants-pocket camera, the biggest tradeoff is low-light performance: small cameras use small sensors, and small sensors generally struggle in low light. Better low-light results usually require a larger sensor and larger optics, which means a larger camera.

So for ultra-compacts, don’t focus too much on brand, CMOS vs. CCD, or maximum ISO claims. On tiny sensors, very high ISO settings often don’t produce great image quality anyway.

The most useful thing to look for is a bright lens (a lens with a wider maximum aperture), because it lets the camera gather more light and helps more than headline ISO numbers. A model with a slightly larger sensor can help too, but size limits still apply.

In short:

• prioritize lens brightness first
• expect limited low-light performance from any true pocket camera
• don’t overvalue max ISO specs
• any recent model from a major camera maker will likely be a big step up from your old camera

If absolute pocketability matters most, even a modern smartphone may be worth considering, since it can be close to ultra-compact quality while always fitting in a pocket.