Let’s assume you have outgrown your phone-cam, and are willing to spend at least a few hundred dollars to get something nicer.

Axiom #1. Consider how important it is for you to get excellent image quality; pocketable camera size; and an affordable price tag. Then pick any two.

Excellent image quality at an affordable price? It’s still hard to beat entry level DSLRs with APS-C sensors, starting ~$400. (Tip: try googling “refurbished Nikon D3200.”) Acknowledge that the size of your camera will cause you to leave it at home at the very instant you want it most.

Pocketable size at an affordable price? Any of the usual serious compacts starting at ~$300 are worth a look: Panasonic LX7; Canon S120; Olympus XZ-10. The limit on image quality comes from the pinky-nail-sized sensor.

Excellent image quality in a tiny camera? Try the new Sony RX100-III, or the Panasonic GM1 (to add interchangeable lenses). But you’re going to pay dearly here—maybe double the price of cheap DSLRs.

Panasonic GM1

It’s mini and mighty; and with two good lenses costs about $1500.

Axiom #2. If you buy an interchangeable-lens camera, but then never take off the kit zoom, you are a chump.

Why? Because zooms that can’t open up beyond f/5.6 at the telephoto end negate any advantage you gained from a larger sensor. Instead, buy a high-end compact with a zoom that’s ~f/2.8 at the tele end and save yourself the extra money and bulk. The low-light image quality will be equivalent.

Get an interchangeable-lens camera only if you’re ready to pay for, and carry around, extra lenses. Even if that’s just a “thrifty 50” costing $120 or so.

Axiom #3. Don’t buy into any interchangeable-lens camera system that has few, or only lame lenses.

Low-light shooters need f/2.0 or better primes in 35mm, 50mm, and 85mm equivalent focal lengths (give or take). Sports and wildlife shooters need more options than one dim telephoto zoom. A decent-quality ultrawide is a plus too. Lame-o “novelty” systems include the Pentax Q, Canon M, Nikon 1, and Samsung NX Mini. Even many APS-C lens lineups fall somewhat short (e.g. Sony mirrorless) or gouge excessively on prices (Pentax DSLR).

DxO Mark Relaunch

June 22, 2010

As of 22 June 2010, the DxO Mark website has been redesigned and greatly expanded—now adding tests of lens/sensor combinations.

There’s certainly an enormous amount of new information there to chew over, although presented in a somewhat bewildering format.

Unfortunately one side effect of the change is that it has broken all of the links my articles included to their sensor comparisons.

Sorry about that. I may try to fix a few of them as I have time.

DxO Mark: µ4/3 versus APS-C

February 15, 2010

DxO Labs has released their sensor test results for two Micro Four Thirds cameras, the Panasonic GF1 and the Olympus E-P2.

Since DxO provides a handy comparison feature, here’s a link comparing both cameras with an APS-C sensor DSLR, the Nikon D5000.

DxO Labs Comparison, m4/3 vs. APS-C

Leading µ4/3 models versus typical DSLR

Note that the D5000 is Nikon’s second-cheapest DSLR, which you can get in a kit for $750. These two µ4/3 models cost more. (Although you can find the Olympus E-P1 for a bit under $700 now.)

I’m not “cherry picking” the D5000 for any particular reason (it is not the best-performing APS-C sensor DSLR). It’s just a current-technology APS-C model which matches the 12 megapixels of the µ4/3 models.

According to DP Review, the sensor used in the cheaper Pentax K-x is very similar.

But the larger, APS-C sensor simply means larger pixels (5.5 microns wide, versus 4.3). And if you click the “dynamic range” and “SNR 18%” tabs, you can see what a huge difference this makes.

For any given noise level, the APS-C camera gains nearly one whole f/stop of ISO sensitivity. The dynamic range is two stops greater.

As always with DxO tests, note that they evaluate just the sensor, based on raw images. They ignore any differences between different cameras’ JPEG processing quality, or any consideration of camera handling, etc.