The New Wave Of Mirrorless
Tuesday, September 17, 2013
The original concept behind the mirrorless interchangeable-lens camera was to provide DSLR image quality without DSLR bulk. The image-quality part was easy: Just use a DSLR sensor—first, Four Thirds size, in the Micro Four Thirds cameras from Panasonic and Olympus, then, APS-C in cameras from Samsung and Sony, and later Fujifilm, Pentax, Canon and Leica. The compact part was achieved largely by eliminating the DSLR's bulky SLR mirror box and pentaprism or pentamirror viewfinder.
The big drawback of early mirrorless cameras was slow autofocusing. DSLRs use phase-detection AF, which (theoretically) can determine from a single reading whether the image is in focus, and if not, in which direction it's out and by how much. Mirrorless cameras couldn't use DSLR-style phase-detection AF because that depended in part on the mirror assembly. So mirrorless cameras used contrast-based AF, which measures contrast right off the image sensor. Contrast-based AF has to take a series of readings to zero in on correct focus, so it's slower than phase-detection. However, since contrast-based AF uses the image sensor to determine focus, it's more accurate than phase-detection AF, whose accuracy depends on the precise alignment of a number of parts, both moving and nonmoving. But initial acquisition speed and tracking moving subjects were definite problems.
The big benefit of phase-detection AF is that it works well on moving subjects. Unfortunately, with most DSLRs, phase-detection AF works only for viewfinder shooting; in Live View and Movie modes, the phase-detection system is inoperative, and the camera has to rely on a very slow implementation of contrast-based AF. (Sony's SLT cameras do employ phase-detection AF in live-view and video shooting, and thus can do videos of moving subjects very well, with eye-level viewing via the built-in EVF.)
Today's mirrorless cameras offer much quicker contrast-based AF than most of their predecessors, and some offer hybrid phase-detection/contrast-based AF systems. More and more mirrorless cameras are providing touch-screen AF—just touch the point on the LCD monitor where you want the camera to focus— especially handy for video shooting.
Because mirrorless cameras don't have optical viewfinders like DSLRs, they operate in live view at all times. This means they wear down their batteries more quickly, although today's cameras do pretty well in power management. It's always wise to carry spare charged batteries, no matter what type of digital camera you use.
Autofocus Technology. Canon (EOS M) offers Hybrid CMOS AF, in which the central phase-detection AF pixels in the center of the image sensor quickly determine the general distance to the subject, while contrast AF fine-tunes the result. Canon introduced Dual Pixel CMOS AF in the EOS 70D DSLR, in which each pixel on the sensor contains two photodiodes, so each pixel can perform phase-detection AF as well as capture light. This is considerably better than the Hybrid CMOS AF, but so far available only in the EOS 70D.
Fujifilm uses 49-point contrast-based AF in its X-series mirrorless cameras in a 7x7 grid. The new X-M1 also offers focus peaking as an aid to manual focusing.
Panasonic's mirrorless models feature Light Speed AF, a contrast-based system in which the camera and lens exchange information at 240 fps for super-quick response. The new GX7 provides focus peaking to aid manual focusing.
Samsung's NX mirrorless cameras use advanced hybrid focus, with phase-detection AF determining the distance to the subject, then contrast AF fine-tuning for maximum accuracy.
Sony's Fast Hybrid AF uses 99 phase-detection sensors at the focal plane working with 25-area contrast AF to optimize AF performance in a wide variety of shooting situations. All of Sony's current mirrorless cameras provide manual focus peaking except the entry-level NEX-3N.
Wi-Fi. Many newer mirrorless cameras offer built-in Wi-Fi. This feature allows you to wirelessly transfer photos to your laptop or smartphone, providing backup and allowing you to upload photos to the Internet via the phone.
Lenses. DSLRs have been around longer than mirrorless cameras, and many use the same lenses as 35mm film SLRs, so they offer a wider range of lenses than mirrorless cameras. But lens lines for mirrorless are expanding rapidly, and you should be able to find the focal lengths you need in just about any manufacturer's lineup.
Video. The newest mirrorless cameras all can do 1080 full HD video at 24p, 30p and/or 60p (see the accompanying chart). This lets you capture the motion and sounds of nature—animals, waterfalls, storms and more.
The Latest And Greatest
>>Fujifilm X-M1. The newest member of Fujifilm's mirrorless X-camera family, the X-M1 is also the smallest and lowest-priced, yet features the same Fujifilm 16.3-megapixel APS-C X-Trans CMOS sensor as the flagship X-Pro1. It's also the first of the X cameras to feature built-in Wi-Fi. The sensor uses a Fujifilm original color filter array with a randomized pattern that minimizes moiré, eliminating the need for an optical low-pass filter and providing added sharpness over conventional Bayer-array sensors. The EXR Processor II complements the sensor, enhancing image quality and providing quick startup. Normal ISO range is 200-6400, expandable to 100-25,600.
One reason why it's smaller than its older brothers is that the X-M1 doesn't have an eye-level viewfinder, but its big 3.0-inch, 920K-dot LCD screen tilts for easy composition, even at odd angles. And the X-M1 has room for the same lithium-ion battery as its larger siblings, good for around 350 shots per charge. If you want an eye-level finder, the X-Pro1 has a hybrid electronic/optical one, and the X-E1, an OLED EVF, along with the same sensor, at higher prices.
Fujifilm brings its legacy in color film to digital with film simulation modes, including Provia (neutral colors), Velvia (dramatic rich colors) and Astia (beautiful skin tones). The X-M1 can shoot at up to 5.6 fps, and you can do multiple exposures, using the first image as a guide to position the second on the LCD monitor. Contrast-based AF includes face detection and subject tracking.
Video capabilities include 1080p and 720p at 30 fps in MOV format with H.264 compression and stereo sound via a built-in microphone. Seven Fujinon X-series lenses are available, from a 14mm through a 55-200mm zoom, providing 35mm-camera-equivalent focal lengths from 21mm through 300mm. Several of the lenses incorporate OIS optical image stabilization.
In keeping with its "flat" compact digicam styling, the E-P5 doesn't have a built-in eye-level viewfinder, but the accessory shoe accepts electronic viewfinders, including the excellent new VF-4. The 3.0-inch, 1.04M-dot LCD monitor tilts and provides touch-screen operation when you want it. (If you want a built-in eye-level viewfinder, the OM-D E-M5 provides one, along with the same sensor, at the same price, but lacks the E-P5's focus peaking and Wi-Fi capabilities.)
The first Olympus mirrorless camera to incorporate Wi-Fi, the E-P5 makes it easy to transfer images wirelessly to your smart device, or even operate the camera remotely from the smart device. The camera can also use your smartphone's built-in GPS to geotag your images.
Besides being able to shoot 1920x1080 full HD, 1280x720 HD and 640x480 video at 30 fps, the E-P5 can do time-lapse movies via its built-in intervalometer. There are also 12 built-in Art Filters that can be applied to individual images or videos. Photo Story mode combines multiple images into a single-image collage; you can also combine several images into one via multiple exposure.
Like all Micro Four Thirds cameras, the E-P5 can use all MFT lenses, and just about any lens for which an adapter can be found. Current Olympus MFT lenses range from a 9-18mm zoom through a 75-300mm zoom, providing 35mm-camera-equivalent focal lengths from 18mm through 600mm (thanks to the MFT sensor's 2.0X crop factor).
A new 16-megapixel Digital Live MOS image sensor combines with the latest Venus Engine to improve image quality and raise the maximum ISO to 25600. Where previous Panasonic mirrorless cameras relied on Mega or Power O.I.S. (optical image stabilization) in specific lenses, the GX7 offers sensor-shift stabilization that works with any lens. As an MFT camera, the GX7 can use any MFT lens and pretty much any lens for which an adapter is available. Panasonic currently offers 22 lenses, from a 7-14mm to a 100-300mm, providing 35mm-camera-equivalent focal lengths from 14mm through 600mm, including a fisheye and a 3D lens.
Contrast-based Light Speed works in light levels as dim as EV -4, while three-level focus peaking is available to aid manual focusing for both stills and video. Video capabilities include 1080/60p in both AVCHD Progressive and MP4 formats, along with 1080/24p and 720/60p in AVCHD and 1080, 720 and 640x480 at 30 fps in MP4. Built-in microphones provide stereo sound. Many of the camera's built-in effects can be applied to videos as well as still images. The GX7 can also do time-lapse, stop-motion animations and in-camera HDR. You can shoot full-resolution still images at 4.3 fps with continuous AF and at up to 40 fps using the electronic shutter with focus locked and live view off.
Using Panasonic's Image App, you can operate the GX7 remotely via Wi-Fi and your smartphone or tablet. NFC lets you make a connection just by tapping the camera and NFC-compatible phone or tablet.
The GX7 features a large, comfortable grip, and has many features that make shooting easier for both the novice and advanced photographer, including front and rear dials, customizable buttons and touch-screen operation on the LCD monitor.
The NX300 is also the world's first single-lens 3D system. When the optional new 45mm ƒ/1.8 2D/3D lens is attached, you can shoot 3D stills and video that can be viewed on 3D-capable TVs and compatible devices. (The NX300 can also use all NX-mount lenses, which currently number 12, ranging from a 12-24mm to an 18-200mm and a 55-200mm, providing the user with 35mm-camera-equivalent focal lengths of 18mm through 300mm.) Samsung's i-Function lets you access a number of functions via the focusing ring on i-Function lenses.
| Are They Really Smaller Than DSLRs?|
Canon's recently introduced EOS Rebel SL1 is by far the smallest DSLR, at 4.6x3.6x2.7 inches (44.7 cubic inches) and 13.1 ounces. The next smallest are in the 5.1x3.8x2.8-inch range (55 cubic inches), weighing 16 ounces and up.
The smallest DSLR-shaped mirrorless models (with eye-level viewfinders) are the Samsung NX20 and Olympus OM-D E-M5, around 4.8x3.5x1.7 inches (28 cubic inches) and 12 to 13 ounces. The Panasonic Lumix DMC-G6 is about the same size as the Canon EOS M, and the Lumix DMC-GH3 is actually a bit larger than the next-smallest DSLRs.
Something to keep in mind is that, while eliminating the SLR mirror box and prism finder does reduce camera size considerably, a lens for an APS-C sensor has to be big enough to cover that format, so lens-size reduction isn't as dramatic as body-size reduction for the DSLR-sensor mirrorless models. Also, while tiny camera systems are a growing trend, they're not for everyone. If your hands like the feel of a mid-range DSLR, they probably will find a mirrorless camera too small.
About the size of the NEX-7, the NEX-6 shares many of its fine features, but with a 16.1-megapixel Exmor APS-C sensor in place of the flagship's 24.3-megapixel unit, ISOs up to 25,600 (vs. 16,000 for the 7) and adding built-in Wi-Fi for linking to TVs/PCs or smartphones. It also adds a mode dial (P/A/S/M/Sweep Panorama) for easy navigation between shooting modes. Like the NEX-7, the NEX-6 has a built-in, pop-up flash.
The NEX-6 can shoot still images at up to 10 fps with continuous tracking AF. It can also shoot full HD 1080 AVCHD video at 60p and 24p, as well as MP4 1080, 720 and 480 video at 30p—all with continuous AF, plus stereo sound via built-in microphones.
While the NEX-6 can use all Sony E-mount lenses, it's especially sweet with the new E-mount 16-50mm ƒ/3.5-5.6 lens, which features Optical SteadyShot image stabilization and is just 13⁄16 inches thick when retracted—a pocketable package. Sony offers 12 native lenses for NEX cameras, from a 10-18mm through a 55-210mm, providing 35mm-camera-equivalent focal lengths from 15mm through 305mm. The LA-EA2 adapter lets you use Sony A-series and legacy Konica Minolta lenses, and provides phase-detection AF with them.
An especially nice feature for those who like to focus manually is peaking, which outlines in-focus edges in your choice of white, red or yellow, making it easy to see just where focus is in the image. For those who like the camera to do it all, there are iAUTO and Superior Auto as well as program, shutter- and aperture-priority AE.