In the last 60 years, the basic design of the «serious» camera has not changed very much. The SLRs of the early 1960s have grown a D, for digital, to become DSLRs. But in spite of newer materials and other refinements, the basic picture-taking mechanism design is still the same.
The SLR was a giant leap for photography. A single-lens reflex camera allows photographers to compose and focus through the exact same lens as the one taking the picture. Both film SLRs and today's digital DSLRs work the same way. A mirror inside the camera intercepts the light path to reflect the image to the viewfinder, only to move out of the way for the split- second it takes to expose the shot.
Mirrorless cameras are a true product of the digital age. Rather than looking through the lens, the photographer sees a screen showing what the camera's sensor will capture. Among other advantages, this allows the camera to be considerably smaller and lighter.
A new way of seeing
The screen in the mirrorless camera (or in certain cases the viewfinder) is just as capable of displaying focus zones and exposure information and even opens up new possibilities for on-screen information such as highlights, focus points, etc. It can also be a lot brighter in low-light situations, amplifying whatever light is available rather than leaving the photographer with natural darkness. DSLRs can't do this.
On the other hand, many photographers just don't like the feeling of looking at a screen when taking photos, and they are just plain more comfortable looking through a lens.
Of course, another advantage of smaller camera bodies is smaller, lighter lenses. These were a little basic back when the first mirrorless models were more of the point-and-shoot variety, but manufacturers now offer some very serious mirrorless models, with an array of equally impressive lenses. And they are still lighter and smaller.
The mirrorless design also allows motion-freezing frame rates up to 20fps, well outside the range of even the fastest DSLRs.
Some photographers have made the migration, selling their DSLR and going with a whole mirrorless system, while others have introduced a mirrorless into their camera bag as a serious backup ...and a great travel accessory.
With APS-C and 3/4 sensors offering up to 24 megapixels, there is no mirrorless compromise in image quality for the DSLR user who uses these formats. More and more high-end lenses are now available for the demanding user. And if you want to measure definition and count pixels, there has now been a full frame mirrorless alternative on the market for over a year with a high quality lens line-up.
One negative factor is that the displays use a lot of energy, so battery life is a concern. It can easily be solved with extra batteries and regular charging, but you'll seldom be getting 1500 frames out of one battery like your DSLR may have delivered.
Compatiblity is a very real issue because even if you can fit most of your DSLR system lenses to a mirrorless, this counters the size and weight advantage quickly. In addition, adaptors do not always transfer all functions. So if you're counting on keeping your lenses, this may bring you back to wondering why not stay with the DSLR.
So photographers have a wider choice out there. And it's not really a matter of which is best. More likely, you should try and see which camera type fits your budget, your present system, and your style. Worth a visit to your Zone Image store...