Mirrorless Camera Guide - 2015 Edition
Mirrorless digital cameras are usually mid-size cameras supporting interchangeable lenses. They are system cameras and each model gives access to a set of compatible lenses. In this guide to mirrorless cameras, you will learn what these cameras are good for, plus how mirrorless systems presently compare. There are much more differences between mirrorless system than DSLR systems, so it is critical to consider both the camera and system before buying.
A mirrorless camera is an interchangeable lens camera without a reflex mirror, the same way that a car is a horseless carriage. Until the appearance of mirrorless cameras, digital cameras with interchangeable lenses were all DSLRs which are defined by having a single lens and a reflex mirror to reflect light towards an optical viewfinder. Mirrorless cameras still have a single lens but no optical viewfinder. The original term, SLD which stands for Single Lens Digital, was easy to confuse and therefore the more descriptive mirrorless name was broadly adopted.
While compact cameras were always appreciated for their size, the same could not be said about their image quality. Meanwhile, DSLRs that consistently deliver excellent image quality are frequently abandoned because of their bulk. Mirrorless cameras were invented to produce high quality images from a compact camera.
Mirrorless Image Quality
The high image-quality traditionally exclusive to DSLRs comes from their large imaging sensors which gather more light than those of compact cameras. Mirrorless cameras currently have sensors of various sizes, from compact-size 1/2.3" ones, all the way to the same full-frame size used by top-of-the-line DSLRs. Image quality varies accordingly, hence there is a greater discrepancy between mirrorless systems than among DSLRs.
The diagram shown on the right displays sensor sizes used in current mirrorless cameras. All rectangles are to scale and even coincide with actual sizes on most computer displays. There are actually two very similar variants of APS-C with the one used by Canon being fractionally smaller.
There are now several full-frame mirrorless digital cameras with resolutions ranging from 12 to 36 MP. Most are relatively compact, while some are just as large as a high-end DSLR. All these produce image-quality comparable to modern full-frame DSLRs.
Mirrorless Camera Size
The size of mirrorless cameras varies equally widely. Despite being called relatively compact and having official measurements similar to compact cameras, mirrorless cameras take on bulk once a lens in mounted. Once ready to shoot, most mirrorless cameras are the size of a typical ultra-zoom, only with higher image-quality and a shorter zoom range.
A camera's sensor-size influences its operational-size because larger sensors require larger lenses. As image quality gets closer to that of a DSLR, so does total size. However, there are so many variables involved that there is no simple relation between image-quality and total-size. Slightly wide to medium focal-length lenses give the most advantage, while telephoto lenses tend to even the gap.
Mirrorless vs DSLR
Mirrorless cameras are evolving faster than any other type of digital cameras. Being the youngest type of digital camera increases chances for smaller companies to take the lead, so more manufacturers are trying. The speed of this evolution plus tremendous variations among mirrorless cameras means that there are also plenty of misconceptions.
Top 10 Mirrorless Camera Facts
- Image quality from the best mirrorless cameras is comparable to that of a DSLR using a sensor of the same size. The latest Micro Four-Thirds cameras even produce output which is very close for common print sizes until moderately high ISOs when compared with typical APS-C DSLRs.
- A lens influences the image quality of a mirrorless camera just as it does for a DSLR. To get the best out of a mirrorless, a sufficiently good lens must be used. The typical kit zoom lens sold with cameras is generally built for compactness rather than quality. Often a better kit with a prime lens is offered too.
- In good light, mirrorless cameras are capable of focusing as quickly as mid-range DSLRs. Autofocus performance drops in low-light, as it does for a DSLR, but the gap widens in terms of speed. Accuracy and sensitivity remain comparable though, at least among recent mirrorless offerings.
- Shooting speed of mirrorless cameras exceeds that of the fastest DSLRs. Continuous shooting up to 60 FPS or 15 FPS with continuous autofocus are available at full-resolution and so are shutter-speeds exceeding 1/8000s.
- Mirrorless cameras are quieter than DSLRs because they do not have a reflex mirror to move between shots. Some use an electronic shutter which makes them nearly silent. This is highly advantageous when shooting in quiet environments.
- The preview on a mirrorless camera is electronic, just like a fixed-lens digital camera or Live-View on a DSLR. The preview varies considerably in terms of sharpness and accuracy between models. The best offer a sharp Exposure-Priority display and EVF. When resolution is too low, it is hard to confirm focus. When the update rate is slow, following action is difficult.
- Mirrorless cameras are power-hungry because their sensor must constantly feed the digital preview. Plus, mirrorless cameras are often fitted with smaller batteries. As a result, the average battery-life comes to 359 shots-per-charge, compared to 912 for DSLRs.*Based on current models as of February 2015.
- Mirrorless cameras are strong in terms of video features. It is possible to shoot video with the camera at eye-level and continuously autofocus while recording, either by on-sensor Phase-Detection or highly optimized Contrast-Detect processors and lenses.
- Plenty of mirrorless cameras are now aimed at professional photographers. Those provide high-end features and controls, including dual or even triple control-dials. While a number are weatherproof and freezeproof, such native lenses are rare. At the extreme though, there is a waterproof mirrorless while no such DSLR exists.
- Lenses mount closer to the sensor on mostExcept for Sony SLT and Pentax K mirrorless models. mirrorless cameras compared to DSLRs. This makes them more adaptable to use legacy lenses, although features such as autofocus are often lost.
SLT - Mirrorless with Pellicle Mirror
Sony makes cameras the size and shape of DSLRs which use the same sensors and lenses. They call these SLT cameras for Single Lens Translucent. They use a semi-transparent mirror to reflect around 30% of light to focus and metering sensors. Contrarily to an SLR, an SLT has an EVF. This viewfinder can preview exposure, color, white-balance and focus, up to its maximum resolution.
All current mirrorless models provide a number of advanced features, although their accessibility greatly differs. Particularly, all of them include: full manual-controls, manual focusing, custom white-balance, continuous drive and full 1080p HD video capture. Most models also sport a hot-shoe. They all offer a wide range of shutter-speeds, at least matching those of entry-level DSLRs, but most often exceeding them.
The high-speed CMOS sensor and continuous Live-View allows mirrorless cameras to provide features usually unavailable to DSLRs. This includes sweeping panorama capture and shooting of images in multiple aspect-ratios which only a handful of DSLRs can do.
Manual focusing has traditionally been difficult with anything other than an optical reflex viewfinder. However, the majority of mirrorless cameras offer a Manual Focus Assist function which magnifies part of the image to make manual focusing easier. A few add something called Focus-Peaking which highlights edges of in-focus areas, something which is impossible to do with an OVF.
As with all interchangeable lens cameras, the aperture range and minimum focus distance of mirrorless ones is determined by the lens being used. Most lenses support screw-on filters to modify incoming light.
Flash, either built-in or add-on, is limited by a sync-speed just like it is on DSLRs because all current mirrorless cameras use a focal-plane shutter and electronic shutters are still relatively slow. Expect sync-speeds between 1/60 and 1/250s.
Mirrorless cameras have taken video capabilities to the next level. Some can capture Ultra-HD 4K video and record it directly to a memory-card. The leading models can provide clean 4K or 1080p HD output, including embedded timecode. Ultra-high-speed and slow-motion video recording is also quite common with frame-rates from 2 to 1200 FPS.
Proceed to Step 2 to learn about Mirrorless Camera Systems from each manufacturer. There we compare what each brand has to offer considering cameras and lenses as a system.
New Cameras & Lenses
Olympus PEN F20 Megapixels Mirrorless (SLD)
Micro Four-Thirds Lens Mount
Fuji Fujinon XF100-400mm F/4.5-5.6R LM OIS WRStabilized & Weatherproof
Fuji X Mount Zoom
Fuji X-Pro224 Megapixels Mirrorless (SLD)
Fuji X Lens Mount
Weatherproof down to -10C
Fuji X-E2s16 Megapixels Mirrorless (SLD)
Fuji X Lens Mount
Fuji X7016 Megapixels Fixed Lens
Fixed 28mm lens
Fuji Finepix XP9016 Megapixels Fixed Lens
5X Wide Optical Zoom
Waterproof to 15m
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