Pentax Q with the 47mm-equivalent f1.9 kit lens.

How much are you willing to sacrifice to shave an inch off your camera That's the question Pentax tacitly raises with its introduction of the Q interchangeable-lens camera (ILC), a model with a body the size and weight of a point-and-shoot (without lens, of course)--and the price of a dSLR. The company achieves this feat of shrinkage by incorporating a tiny 1/2.3-inch backside-illuminated (BSI) CMOS sensor, which in turn allows for a smaller-than-usual lens mount and more compact lenses. And it looks like there will be a lot to like in the Q--it's got an attractive, retro look' a light but solid body' well-designed flash' and enthusiast-friendly features like 1080/30p video capture and time lapse. But the drawbacks. Oy, the drawbacks. And all to lose that extra inch. (Okay, it's not exactly an inch: it's 1.3 cubic inches smaller than the NEX-C3.)

To give you some sense of how small a 1/2.3-inch sensor is, the Q lens mount is roughly 67% smaller than Pentax's traditional APS-C K-mount. It has a 5.5x magnification factor, compared to 1.5x for APS-C-based ILCs or 2x for Micro Four Thirds models. That means, for example, that an 18mm lens which produces the equivalent angle of view of 27mm on a Sony ILC or 36mm on an Olympus or Panasonic ILC, would produce a 99mm-equivalent on the Q. As a result, producing a wide angle lens for this camera will be very, very difficult.

The small sensor impacts depth-of-field (DOF) as well. The smaller the sensor, the shorter the focal length needs to be to produce a given shallow DOF (i.e., blurring in front of and behind from the focal plane of the subject) at close distances. But as I just mentioned, producing the necessary wide-angle lens will be difficult. Pentax implicitly acknowledges this problem by supplying a bokeh-control filter in the camera. Other ILCs and point-and-shoots also include this capability, usually called "background defocus." But the Q will really need it. (You can play around with this great DOF calculator to see what I mean.)

The small lens mount introduces further complications. None of the ILCs can natively handle lenses designed for APS-C or full-frame cameras, but they all provide adapters to facilitate backward compatibility. Pentax has no plans to ship an adapter for old lenses. That's a huge disincentive for the Pentaxians who might otherwise be lining up to buy the Q. I think a niche third-party would probably step in to fill the void, but the fact that Pentax isn't doing it signals to me that there are some technical challenges beyond just incongruous sizing that may surface here.

Then, of course, is the issue with the sensor itself. BSI technology was developed to improve the low-light sensitivity of small sensors. And it works great for that. But at least in all the BSI cameras we've seen, the image quality has been great for inexpensive to midpriced point and shoots. Compared to the even modestly larger non-BSI sensors in enthusiast cameras like the Canon PowerShot G12 or Panasonic Lumix DMC-LX5, the daylight images aren't quite as good. That said, the Q uses the most recent Sony BSI sensor (likely also used by the Nikon Coolpix P300) and Pentax dropped the antialiasing filter, so it might deliver better results than we've seen historically.

The Toy Wide lens

However, it's telling that 2 of the five lenses Pentax will ship at launch are so-called "toy" lenses (a 35mm "wide" and a 100mm telephoto for $79.95 each) and one is a fisheye ($129.95): all are cheap lenses designed to maximize the fun but not the photo quality. The standard 24-80mm f2.8-4.5 lens won't be part of a kit and will run $299.95. Instead, the kit will include a 47mm-equivalent f1.9 lens.

Here's the rub: if the Q were targeted at mainstream consumers, a lot of this probably wouldn't matter. But it's targeted--and priced--for enthusiasts, who do care about this stuff.

The competition

According to the press release, "the Q carves out an entirely new camera category that extends beyond traditional digital compact, APS-C or 4/3 digital cameras." This is a bit disingenuous' the Q isn't so much smaller than models like the Panasonic Lumix DMC-GF3 or Sony NEX series that it's in a category all by itself. All of them are jacket-pocket-friendly equipped with a pancake prime lens, but none of them are with a standard zoom. The Q's body is roughly the size of the Canon PowerShot S95, but as with all ILCs, the lens can't retract into the body and so, unless you have TARDIS pockets, there will always be an issue. It is lighter, though, and like Panasonic and Olympus, the lenses are much lighter than Sony's E-mount offerings. If not for size, I'm not sure exactly what niche Pentax thinks it's carving out. Retro Olympus got there first. Overpricing Everyone else has been there, still doing that, though at $800 Pentax seems to be trying to outdo the crowd.

In fact, no matter how you categorize it, there seem to be a surfeit of competitive options, which include compact ILCs or enthusiast compacts. Here's how it stacks up compared to the ILCs:

 ' Panasonic Lumix DMC-GF3 Pentax Q Sony Alpha NEX-C3 Sony Alpha NEX-5 Sensor (effective resolution) 12.1-megapixel Live MOS 12.4-megapixel BSI CMOS 16.2-megapixel Exmor HD CMOS 14.2-megapixel Exmor CMOS 17.3 x 13.0mm 1/2.3-inch 23.5mm x 15.6mm 23.4mm x 15.6mm Focal-length multiplier 2.0x 5.5x 1.5x 1.5x Sensitivity range ISO 100 - ISO 6400 ISO 125 - ISO 6400 ISO 200 - ISO 12,800 ISO 200 - ISO 12,800 Continuous shooting 3.8fps unlimited JPEG/7 raw 5fps 5 JPEG/n/a (1.5fps raw) 2.5 fps 18 JPEG/ 6 raw (5.5fps with fixed exposure) 2.3 fps unlimited JPEG/8 raw (7fps with fixed exposure) Viewfinder magnification/ effective magnification None Optional optical for prime lens None None Autofocus 23-area contrast AF 25-point contrast AF 25-point contrast AF 25-point contrast AF Shutter speed 60-1/4000 sec' 1/160 sec x-sync 30-1/2000 sec.' bulb' 1/125 sec flash sync 30-1/4000 sec.' bulb' 1/160 sec flash sync 30-1/4000 sec.' bulb' 1/160 sec flash sync Metering 144 zone n/a 49 zone 40 segment Flash Yes Yes Included optional Included optional Image stabilization Optical Sensor shift Optical Optical Video 1080/60i/50i @ 17 Mbps 720/60p @17 Mbps AVCHD or Motion JPEG QuickTime MOV

1080/30p H.264 MPEG-4

The Q has a couple of advantages, including 1080/30p video, in-camera image stabilization that's effective during movie capture and a standard hot shoe. And while the burst performance on all of these is suboptimal, the Pentax seems exceptionally lame' it's 5fps, but only for a second. And who knows how long it will take to save the 5 images. It has a low resolution, fixed LCD and seriously sad battery life' I hope the latter gets fixed before it ships. Performance is an important unknown here, but as it didn't come up during briefings as one of the design goals of the camera, I suspect it won't break any records. I really would expect it to cost less than these competitors, not more' that 1.3 cubic inches just isn't worth it to me.

Here are some compact cameras that I think many people will be considering instead as well:

 ' Canon PowerShot S95 Nikon Coolpix P300 Pentax Q Olympus XZ-1 Sensor (effective resolution) 10-megapixel CCD 12-megapixel BSI CMOS 12.4-megapixel BSI CMOS 10-megapixel CCD 1/1.7-inch 1/2.3-inch 1/2.3-inch 1/1.63-inch Sensitivity range ISO 80 - ISO 3200 ISO 160 - ISO 3200 ISO 125 - ISO 6400 ISO 100 - ISO 6,400 Lens 28-105mm f2-4.9 3.8x 24-100mm f1.8-4.9 4.2x 47mm f1.9 1x 28-112mm f1.8-2.5 4x Closest focus (inches) 2.0 1.2 n/a 0.4 Continuous shooting 1.9fps frames n/a 8fps 7 JPEG 5fps 5 JPEG (1.5fps raw) 2fps 23 JPEG/8 raw Viewfinder Optical None Optional optical for prime lens Optional EVF Autofocus n/a Contrast AF n/a Contrast AF 25-point contrast AF 11 area Contrast AF Metering n/a 224 segment n/a 324 area Shutter 15-1/1600 sec 8-1/2000 sec 30-1/2000 sec.' bulb' 1/125 sec flash sync 60-1/2000 sec' bulb to 16 min Flash Yes Yes Yes Yes Hot shoe No No Yes Yes LCD 3-inch fixed 461,000 dots 3-inch fixed 921,000 dots 3-inch fixed touch screen 460,000 dots 3-inch fixed OLED 610,000 dots Image stabilization Optical Optical Sensor shift Sensor shift Video (best quality) 720/24p H.264 QuickTime MOV Stereo 1080/30p H.264 QuickTime MOV Stereo 1080/30p H.264 MPEG-4 720/30p Motion JPEG AVI Manual iris and shutter in video No No Yes No Optical zoom while recording No Yes n/a No Mic input No No No Yes Battery life (CIPA rating) 220 shots 240 shots 230 shots 320 shots Dimensions (WHD, inches) 3.9 x 2.3 x 1.2 4.1 x 2.3 x 1.3 3.9 x 2.3 x 1.2 4.4 x 2.6 x 1.7 Weight (ounces) 6.8 6.7 (est) 7.1 (est) 9.6 Mfr. Price $399.99 $329.95 $799.99 (with 47mm- equivalent f1.9 lens) $499.99 Availability August 2010 March 2011 Fall 2011 January 2011

As we've seen for years, you don't need interchangeable lenses to get creative, and the not-inconsiderable price difference between the Q and otherwise similarly specced compact models would give me pause as a buyer. And the biggest irony is that the fixed-lens cameras still offer a broader focal range than will initially be available for the Q system. (The Q's future includes a telephoto and an "ultra wide" but Pentax didn't offer much detail.) The Q may have some advantage over any given model in some aspect--for instance, the P300 doesn't support raw while the Q produces DNG files--but overall its only substantial perk is the lens mount.

In terms of features, the Q is pretty typical for any modern camera. There are Smart Effects, the usual assortment of shooting effects plus the more unusual Cross Process option' you can combine them. It also offers a time-lapse shooting mode, which I'm surprised more cameras don't offer, and customizable presets. There are a couple of unique aspects to the design, including a clever flash that pops way up to decrease the occurrence of red eye. A dial on the front of the camera can be used to change settings contextually' I'll reserve judgment on that, because it seems an odd choice. And unfortunately, the camera lacks a dedicated movie-record button.

I don't think the Q was designed with the US market in mind. We like small, but not at any cost. So it makes sense that Pentax is shipping the Q in Japan during the summer, while it's slated for a Fall release here. It remains to be seen whether the tradeoffs Pentax made to make it small were worth it, given how late to market the company is and how expensive the camera turned out. Despite everything, I really would like to be surprised.