Mirrorless cameras are typically smaller than DSLRs, and their shorter-focal-length lenses are also generally much more compact than those for DSLRs (although longer lenses for bigger-sensor cameras—not so much). So it’s easier to carry a mirrorless camera around, and a whole system takes up less space and weighs considerably less, handy when traveling or hiking to an ideal camera viewpoint. However, the larger DSLR bodies provide better balance when handholding longer lenses, and some photographers find tiny camera bodies uncomfortable, even with normal lenses. That’s something you’ll have to decide for yourself by holding the cameras you’re considering.
Fact Or Fiction?
DSLRs are faster than mirrorless cameras.
|Fiction (mostly). It depends on how you’re measuring speed. The phase-detection AF systems used in DSLRs are generally faster than the contrast-detection systems in mirrorless cameras, though the gap has narrowed in recent years with hybrid AF systems that employ phase-detection AF on the camera sensor. If you’re measuring speed in terms of frames per second, with no mirror to move, mirrorless cameras offer impressive burst rates, some as fast as 20 fps with AF for each frame.|
Since they use similar, if not identical, image sensors, mirrorless cameras pretty much deliver DSLR image quality. In DxOMark.com’s overall sensor ratings, the top full-frame DSLR scored 97, while the top full-frame mirrorless camera scored 95. In APS-C-sensor cameras, the top DSLR scored 87, and the top mirrorless camera scored 83. The takeaway is that, for image quality, sensor size is more important than camera type—within a given brand, all the current full-frame cameras outscore the current APS-C ones. That said, even smaller-sensor cameras are capable of delivering excellent image quality. Today, for most photographers, how a camera feels in use, its feature set and its AF performance will be more important than its image sensor.
DSLRs use traditional SLR optical TTL (through-the-lens) viewfinders. Some mirrorless cameras provide only an LCD monitor for composing, like compact point-and-shoot cameras, while others also provide eye-level electronic viewfinders.
SLR finders are always “on” and don’t require battery power or wake-up times. Full-time live view, whether with an EVF or external monitor, is the main reason why mirrorless cameras don’t get nearly as many shots per charge as DSLRs (often smaller batteries, to keep camera size down, is another). And SLR finders show the image formed by the lens, in real time. Longtime SLR users tend to prefer the DSLR finders they’ve grown used to.
You may prefer electronic viewfinders. Rather than showing you the image produced by the lens, these show you the image produced by the sensor. Thus, you see not only the scene, but the effects of exposure and white balance and in-camera effects, along with lots of information, including histograms (with some cameras)—things the DSLR optical finder can’t show you.
When mirrorless cameras first appeared (2008), even entry-level DSLRs blew them away in AF performance. The phase-detection systems in the DSLRs can tell with a single reading whether the subject is in focus, and if not, by how much. The contrast-based AF systems in mirrorless cameras (and in most DSLRs, when in Live View mode) take a reading of the contrast, then adjust focus and take another reading. If the contrast is higher, they adjust focus further in that direction and take another reading, continuing until contrast starts to drop off, then going back to the distance of highest contrast. If the second reading shows lower contrast than the first, the system moves focus the other way, and repeats.
Fact Or Fiction?
DSLRs offer superior image quality.
|Fiction. Image quality is determined by the imaging sensor mostly. Larger sensors generally provide better image quality. Mirrorless models are available in a range of sensor sizes, just like DSLRs.|
Today, contrast-based AF has dramatically improved, with reading rates up to 240 fps and better focusing algorithms. In fact, the best contrast-based systems in mirrorless cameras can establish focus more quickly than many DSLRs. And since the focus is read right at the image sensor, it’s more accurate than phase-detection, which depends on the precise alignment of a number of moving parts. Contrast systems are also very good at tracking a subject moving across the field of view (although they still aren’t as good as phase-detection at dealing with subjects moving toward the camera).
More recently, we’ve seen hybrid AF systems appear, which employ phase-detection sensors on the image sensor. These are used to quickly “ballpark” focus, with contrast then taking over to fine-tune it. In general, mirrorless cameras provide better autofocusing during video shooting than DSLRs do.
With no mirror to flip up and down, mirrorless cameras can offer some remarkable shooting rates—some up to 20 fps with AF for each frame, and 60 fps with focus locked at the first shot. But most pro action shooters use DSLRs for their AF performance on quick, erratically moving subjects, better selection of action lenses (i.e., fast telephotos) and large buffers that let them shoot longer bursts in RAW format. For landscapes and most travel photography, shooting spe
ed isn’t a big factor.
Fact Or Fiction?
Some DSLRs are just as compact as mirrorless cameras.
|Fact. Nikon’s D3300 (4.9 x 3.9 x 3.0 inches) and Canon’s EOS Rebel SL1 (4.6 x 3.6 x 2.7 inches) are actually slightly smaller than Samsung’s NX1 (5.5 x 4.0 x 2.6 inches), for example.|
All of today’s mirrorless cameras, and nearly all DSLRs, can shoot videos, as well as still images. All can do HD (1280×720) video, most can do full HD (1920×1080), at 24 fps, 30 fps and even 60 fps. A few even can do 4K (4096×2160 or 3840×2160) at 24 or 30 fps.
Time-lapse capability is another popular feature that some newer models make easy to do in-camera, producing finished time-lapse video clips. If this interests you, it might help you narrow the cameras you’re considering.
|All DSLRs have an eye-level viewfinder, but most mirrorless models do not, or offer one only as a shoe-mount accessory. Before you settle on a mirrorless model that doesn’t have an EVF built in or as an option, try it in outdoor use. Camera LCDs often can be difficult to see clearly in bright outdoor conditions, rendering the camera pretty much useless without an EVF.|