This article concentrates on the more permanent characteristics of each brand, not features that may change from model to model.
Full Professional System
Only Nikon and Canon make the full range of equipment (especially lenses) that is required by professionals.
This will not be important for the majority of photography enthusiasts. “Professional” doesn’t have to mean better. Some professionals like big, heavy, fast, tough cameras which a more sensible photographer would leave at home.
Advantage: Canon, Nikon.
Size and Weight
Olympus, Panasonic and Samsung use the “four thirds” camera standard with a 2x crop factor compared to traditional film cameras. Other brands have 1.5x and 1.6x crop factors.
The 2x crop factor means that a 300mm f2.8 lens is equivalent to a 600mm f2.8 lens on a “four thirds” camera (only 450mm or 480mm on the other brands). With these super telephoto lenses weighing a few kilograms, this gives “four thirds” a big weight advantage.
Lighter standard-zooms will show a smaller (sometimes zero) weight advantage.
Advantage: Olympus, Panasonic, Samsung.
Olympus, Pentax, Samsung and Sony has stabilization built into the camera body (except for some budget models) – image stabilization is available for all the lenses.
Canon, Nikon and Panasonic (despite being “four thirds” like Olympus) put the stabilization into the lens. The problem is that they might not put it into some lenses. For example the Canon and Nikon 50mm f1.4 autofocus lenses are not stabilized.
Advantage: Olympus, Pentax, Samsung, Sony.
The larger the image sensor, the better the high-ISO performance (less noise).
- Full frame cameras (1x crop factor) have the largest image sensors and the best low-light performance but are targeted at professionals and cost thousands of dollars (Canon, Nikon). Canon also has 1.3x cameras.
- 1.5x (Nikon, Pentax, Sony) and 1.6x (Canon) are the most popular crop factors, with average low-light performance.
- The smaller 2x “four thirds” image sensors are at a slight disadvantage in low-light situations, but still give comparable performance in bright light.
Advantage: Canon, Nikon, Pentax, Sony.
The layout of the controls can greatly affect not just the enjoyment of using the camera but also the speed at which settings can be changed. This can mean the difference between getting and missing a shot.
Obviously this is a subjective characteristic and no objective recommendation can be made. Ergonomics can also vary greatly within a manufacturer’s range of camera models.
While more popular doesn’t have to mean better, a larger market share does mean:
- More support from third-party lens and accessory makers, websites (forums, how-to and equipment review articles)
- Easier sharing of lenses with friends and family
- Possibly higher resale value
Advantage: Canon, Nikon.
In today’s competitive market, no inferior DSLR brand can survive. Any DSLR from one of the major manufacturers will give excellent results. That having been said, here are some recommendations:
- General photography, expandable to full professional system: Canon, Nikon.
- Available-light photography, sharpness limited by camera-shake. Example is photojournalism where the camera is hand-held (need stabilization with prime lenses): Olympus, Pentax, Samsung, Sony.
- Available-light photography, sharpness limited by subject movement. Example is sports photography which requires high shutter speeds (need 1x full frame, low noise high-ISO image sensor): Canon, Nikon.
- Lightweight travel, unobtrusive photojournalism, wildlife photography (need small lens, large 2x crop factor magnification): Olympus, Panasonic, Samsung.