Powerful ProcessingIt all starts with a powerful processor. Canon's DIGIC 4, Nikon's most recent EXPEED, Olympus' TruePic III+ and V, Panasonic's Venus Engine HD, Pentax's PRIME II and Sony's latest Bionz processors provide the power to support the evolving capabilities of the newer digital cameras.
Each camera model, be it a D-SLR or compact, features processing custom-tailored to that camera and its target users' needs. The processor works with the image sensor (which also is being improved with each new generation) and the latest algorithms to provide some impressive new capabilities, including HD video and more.
Live ViewWhile compact digital cameras have provided Live View operation from the beginning, this handy feature made its D-SLR debut just three years ago in the Olympus E-330. Today, Live View is available in more D-SLRs than not, from entry-level through high-end pro models.
The traditional SLR optical (TTL) finder works well for most serious shooting, but there are benefits to Live View. One is that using the LCD monitor to frame images makes composing at odd angles easier (although, sadly, only a handful of D-SLRs with Live View have tilting/swiveling monitors that make odd-angle compositions easy).
Another Live View advantage is easier manual focusing in dim light situations (or when using a teleconverter, which reduces light transmission and makes for a dim viewfinder image). The Live View image is bright and can be magnified greatly for easier focusing. This is best done with the camera mounted on a tripod, and bear in mind that there's no built-in dioptric correction for the LCD monitor as there is for the SLR optical viewfinder. If you need glasses to see up close, you'll need them to use Live View. Live View also provides 100% coverage of the actual image area, important for precise framing and compositions.
Some D-SLRs (mostly higher-end models) provide both phase-detection and contrast-based autofocusing in Live View. Phase-detection is the AF system employed for non-Live View shooting (Canon calls this Quick mode, Nikon calls it Handheld mode, Olympus calls it AF Sensor mode) and offers the advantage of quick performance. The drawback is that the SLR mirror must drop down into viewing position for autofocusing to occur, which momentarily disrupts the Live View. Contrast-based AF (Canon calls this Live mode, Nikon calls it Tripod mode, Olympus calls it Imager AF mode) provides focal-plane focusing right off the image sensor, so there's no blackout of the Live View during focusing. The drawback is that contrast-based AF is slower than phase-detection AF. Sony's DSLR-A300, A330, A350 and A380 models have a second sensor that provides the Live View image, so the camera's quick phase-detection AF can be used with no disruption of the live image. For more about the differences between phase- and contrast-detection AF, see the article "How Autofocus Works" on our website, dpmag.com.
With some Live View cameras, you can send the live image to a computer via a USB connection (or wirelessly with an optional wireless remote unit) for viewing on a computer monitor and operate the camera from the computer via the supplied or optional software. Seeing the live image and previewing exposure and effects on the big computer monitor is wonderful and not just limited to studio work—you can send the Live View image to a laptop computer in the field.