In the past few years there have been dramatic increases in buffer memory and/or reductions in the physical size of the buffer component. (We’re using 256GB SD cards—64 times the memory—and read/write speeds are proportionally higher, too.) Processors have come up in power and down in size, as well, and components of the sensor chip itself can be used to serve processing functions.
More components can be placed on a single circuit board, rather than on several boards in different locations within the cameras. Sensor chips today run cooler, although still not enough to provide as much noise suppression as DSLRs can do.
One big factor to the critical mass of this new breed of high-performance compacts is the maturation of the DSLR market. Pretty much everyone who wants a DSLR has one, and many are on their second or third or fourth DSLR. And just as happened in the 1980s and 1990s, these shooters are hankering for pocket cameras that can give them the imaging quality they expect from their cameras. And more.
Pros and Cons of the New Compacts
The major reason for a big sensor, of course, is image quality: high resolution, with low noise and accurate colors. Our table on page 70 shows Popular Photography Lab Test results for these cameras at a glance. As you can see, the results are pretty close for the whole pack, with some numbers so close as to be statistically insignificant. All told, you can expect about the same image quality from these cameras as you’d get from a 16MP DSLR, at least up to ISO 1600 or so.
To be sure, “advanced compacts” such as Canon’s PowerShot G series, Nikon’s Coolpix P models, and Panasonic’s Lumix LX line can provide near-DSLR image quality levels, at least at moderate ISO levels. But there’s another big plus to the big sensor: the ability to limit depth of field far more than the smaller sensors in these cameras can. For reference, f/2.8 on a Canon G12 will give you the same depth of field as will f/9 on an APS-C sensor camera, with both set to a 28mm equivalent.
Limitations, there are a few. To have reasonably large-apertures and compact lenses, the optics have a single focal length—zooms need not apply.
The issue of sensor heat is evident in the imaging performance of the cameras. Typically they reach tested Unacceptable noise levels at one or two ISO steps lower than a DSLR equivalent, and the extra noise suppression needed also drops resolution down a notch as well. The fact is, as good as these cameras are, they actually underperform compared to interchangeable-lens cameras with the same or similar sensors.
Click for a larger version of our comparison chart