Poll: Best SLR rivals to Canon and Nikon

Update 8:12 a.m. PST: We added Fujifilm to the poll.

Canon and Nikon dominate the SLR camera business, but if you're entering the market or buying a new camera, it would behoove you to look at other options, too.

One interesting question, though, is who's got the best alternatives today. It's a relevant question for someone buying a first SLR or deciding whether to stick with an existing brand or change. From another perspective, who should Nikon and Canon be fretting about most among competitors?

I'd love to see your vote and hear your likes and dislikes, and other thoughts in the Talkback section below.

There are two broad classes of alternatives. First, the companies that already have an established presence in the camera market: Fujifilm, Leica, Olympus, Pentax, and Sigma. Second are the newcomers from the consumer electronics realm: Panasonic, Samsung, and Sony.

There are some alliances here that make that rough division more complicated than might appear at first blush. First, Sony's SLR effort is built on the assets it acquired from Konica-Minolta, a longtime SLR maker. Second, Samsung's SLRs at present are basically rebadged Pentax models with some minor differences, such as a blue ring around the lenses rather than a green one. Third, Panasonic has a technology partnership with Leica, and both those makers' lenses use the Four Thirds system that Olympus founded when it introduced digital SLRs.

Those partnerships all are important not just because the newcomers can get a technological boost, but also because it means buyers have a wider choice of lenses. A lot of people never buy any lens besides the basic "kit" lens that came with the camera. But for those who want to grow, it's good to have a bunch of telephotos, wide angles, fixed-focal length primes, macros, and fisheyes to choose from.

I'm not sure if this is a coincidence, but one thing that unites all those chasing Nikon and Canon is the decision to build image stabilization into the camera body rather than into the lens. With that approach, the image sensor shifts side to side and sometimes rotationally to compensate for the photographer's shaky hands. It also means that image stabilization works with older lenses and doesn't have to be built into new ones. On the flip side, Nikon and Canon argue for putting image stabilization into the lens, which they argue produces better results.

Another big difference is that only Nikon and Canon so far have models with full-frame image sensors.

If you're wedded to the big two, you might be curious to know how users voted earlier this month in our Canon vs. Nikon SLR poll: Nikon beat Canon with 55 percent of more than 11,000 voters. (Yes, we do employ measures to prevent people from voting multiple times.)

But for those evaluating the alternatives, here are some other tidbits to consider.

• The Four Thirds allies have the benefit of a clean break from the film past, with all-new lenses designed for the sensors that are smaller than a full frame of 35mm film. That means they could design lenses that are smaller and cheaper than those who have to worry about supporting older film cameras or who are planning on offering full-frame models in the future. And it means customers can intermix nice lenses from one company with cameras from another, a nice break from the usual SLR lens incompatibility barriers.

• Images from Four Thirds cameras have an aspect ratio of 4:3 (surprise!), the squarish proportions used in standard-definition TVs. But 35mm film cameras, as well as the digital SLRs from Pentax, Samsung, Sony, and Sigma, use a more 3:2 ratio. Personally, I prefer the latter, since it permits more dramatic vertical or horizontal orientations. And bear in mind that HDTV uses an even wider 16:9 ratio.

• Fujifilm uses the same camera bodies as Nikon, meaning that the lenses are compatible, but it uses its own sensor design, called SuperCCD. These sensors employ an unconventional pixel layout that in effect devotes two sensor sites to each pixel, expanding the dynamic range of the image at the expense of a lower overall pixel count.

• Sony not only has benefit of its Konica-Minolta history, it also has a lot of in-house manufacturing expertise--notably image sensors. That allows it to control more of its own destiny, plump up profit margins, and tightly integrate components.

• Sigma uses Foveon's unusual image sensor in its SD14 digital SLR. Most image sensors have a checkerboard pattern of red, green, and blue pixels; the camera processes the data to produce red, green, and blue values for each pixel after the fact. In contrast, Foveon's sensor captures red, green, and blue data for each pixel. In theory that could mean images with finer detail and fewer pesky artifacts, but in practice it's hard to overlook the conspicuous absence so far of Foveon chips elsewhere in the industry.

• Panasonic and Sony have released only two SLRs each so far, one in 2006 and one in 2007, but bet on them to flesh out their product lines to reach a broader market. Sony in particular has promised a new professional-grade model--an ambitious move--but the company already has released a sizable number of new lenses.

• Olympus and Pentax may not have the professional-market clout of Canon and Nikon, but they're trying hard to appeal to higher-end users. Olympus' new, top-end E-3 and Pentax's flagship K10D both are designed to resist water and dust, for example.