Appearance and Interface
Both the Sigma DP1 and the Canon PowerShot G9 yearn to look cool and “professional” with black metal sheathing and crisp styling. However, Sigma goes minimalist while Canon festoons the G9 with controls and badges that recall Canon's market-dominating DSLRs.

The front of the Sigma DP1 is clean. The lens barrel is big and slightly off-center to the right. The front, back and sides of the DP1 are flat. Its skin is essentially two pieces of metal – the front stamping wraps halfway around the sides and top to meet the back cover, which also wraps around the edges. Both sides of the DP1 have flush-mounted chrome strap lugs which fit only very thin cord, and don't take it very easily.

The Canon G9 has a visually busy front with a polished metal ring around the lens, a two-part automatic lens cover, a button to pop off the ring around the lens, a viewfinder window, a flash, brand and model badges, an autofocus light, and a contoured grip.

The Sigma DP1's controls are on the top and back of the camera, and they combine the camera's clean look with echoes of classic film cameras. On top, the largest control is a mode dial which seems like an homage to old Leica shutter speed dials, down to the single red setting (on Leicas, it was the maximum flash sync speed. Here, it's point-and-shoot mode.) The shutter release is large and circular, with a short travel that doesn't provide much feedback to indicate that a shot has been taken. There's a hot shoe directly over the lens for flashes and at far left a small pop-up flash that's more useful for fill light than for lighting the whole scene. The power button is recessed into a collar, but that doesn’t keep the DP1 from accidentally being turned on. That's a problem because the lens telescopes out when the camera is turned on, and that shouldn't happen unless the lens cap is removed. The lens cap is a simple plastic item that the user must remove and replace manually.
 

Sigma DP1

Canon G9

Along the top edge of the back are the flash switch, which pops up the flash and turns it on, and a small dial for manual focus. The 2.5-inch LCD takes up a bit more than half of the back. The right-hand portion of the back has a small, straight thumb rest, which would be more effective if it were larger, curved and covered with something rubbery. A five-way controller brings up the menus and navigates them, and navigates the screen in playback. The playback and screen display buttons are below the controller. The exposure compensation button is above it, and does double duty as the trash button. The AE lock button is near the top in a convenient spot for the user's thumb.

A pair of buttons in the upper right function to increase or decrease magnification in playback. They are sensibly placed, and like the other buttons on the DP1, seem well-made and durable. Still, a minor thing about them serves to undercut the DP1's marketing message that the camera is somehow designed without compromise as an elegant, elite, unique, groundbreaking, special camera for special photographers. The buttons are labeled “W” and “T” - as in “wide” and “telephoto.” The Sigma DP1 doesn't have wide and telephoto settings, because its lens doesn't zoom. Apparently, the buttons are cadged from some other compact camera.

Canon packed the G9's top and back with controls. ISO has a dial, rather than a menu item, and the dials and some of the buttons are large in relation to the size of the camera. The G9's 3-inch display leaves little room for controls on the back, so Canon stacks a four-way controller on top of its trademarked “Quick Control” wheel, with a function button in the center. The three-tiered assembly is a bit like a tiny black wedding cake. Four independent buttons surround it.

Sigma DP1	Canon G9

Both the Sigma DP1 and the Canon G9 have lenses that telescope in and out for storage and operation. When they're retracted, the cameras are small and convenient to carry, and in the case of the G9, it seems unlikely that a long zoom (210mm equivalent) could be part of a sensibly-shaped compact camera. The telescope mechanisms have significant drawbacks, the most obvious being that they are delicate and susceptible to damage.

Canon G9	Sigma DP1

We screwed up with the DP1 a few times, accidentally bumping the power button while the lens cap was on the camera. The little electric motor that extends the lens ground away for several seconds, then gave up: it's not strong enough to pop off the cap. We took the lens cap off with a little anxiety – wrecking a loaner camera would have been an unfortunate new experience for us, though we know someone who lost track of a prototype Canon 5D once. Like a stunned starling, the DP1 was disconcertingly inert for several seconds, but roused itself to function properly. The motor has a clutch, but stressing it is both easy to do and not a good thing to do. We didn't have that problem with the Canon, since it has an automatic lens cap which can't block the telescoping process.

Both cameras made us think of the Canon PowerShot A510 we threw away a couple years ago when the lens got bent out of alignment. The optical assemblies are lightly built so that small motors can move them into place and focus them without undue power, and they are really delicate. It's also worth noting that the lens barrels which are exposed when the cameras shoot go back inside the cameras when they are retracted, carrying dirt and dust with them.

Obviously, both the G9 and the DP1 use the mechanism, so each camera is likely prey to its drawbacks. It seems to us, though, that the DP1 is less justified in having a telescoping lens. The DP1 in shooting mode is thicker than a Leica M-series with a 35mm lens. The Leica has a much larger image area and a longer focal length. It just doesn't seem necessary for a 16mm prime lens to stick out that far.

Battery
Both the Canon G9 and the Sigma DP1 use lithium-ion batteries. The G9's is 7.4 volts with a 720mAh capacity. The DP1's is 3.7 volts and 1300mAh, and physically much smaller than the G9's. We assume that the larger Foveon imaging chip in the DP1 draws more power than the CCD in the G9; even with a more energetic battery and a smaller LCD, the DP1 ran about half as long as the G9 when we were out shooting with the two cameras.