PANASONICPanasonic introduced the first mirrorless Micro Four Thirds System camera, the Lumix DMC-G1, in 2008. Today, the company offers a next-generation lineup of Micro Four Thirds models. The Lumix DMC-GH2, DMC-G2 and DMC-G10 look like mini-DSLRs, with their built-in, eye-level electronic viewfinders complementing the full-time, live-view LCD monitors. The Lumix DMC-GF2 looks like a compact digital camera, but features a Four Thirds sensor like the other Panasonic models.
The super-compact GF2 features a 12.1-megapixel Four Thirds sensor, 3.2 fps shooting, similar video capabilities to the GH2 and more. It even can do 3D still images and videos with the optional Lumix G 12.5mm ƒ/12 lens.
DSLRs use phase-detection AF for still photos in viewfinder mode, and most let you choose between phase-detection AF and contrast-detection AF in live-view and video modes.
Phase-detection AF is quick and much better suited for action subjects. But it requires the SLR mirror to be in the down (viewing) position, so it momentarily disrupts the live view during focusing. Contrast-based AF reads right off the image sensor, so it doesn't disrupt the live image during focusing, but it's noticeably slower than phase-detection AF and not as well suited for action photography. There are a few exceptions. Sony live-view DSLRs employ a second sensor to provide the live image and thus can employ the same quick phase-detection AF system for live-view shooting as for viewfinder shooting. Panasonic's recent mirrorless cameras have very quick contrast-based AF, but no phase-detection AF.
Longtime 35mm SLR maker Pentax introduced its first DSLR (the *ist D) in 2003 and has since produced 14 more. The current lineup consists of the pro-oriented K-5, the mid-level K-7, and the entry-level K-r and K-x.