Most DSLRs already have a wide selection of lenses available, including those made by the camera maker and also from independent lens makers like Sigma, Tamron and Tokina. The third-party lenses include lower-cost alternatives to some of the camera manufacturers’ options, along with lenses that aren’t available in the camera makers’ lines, and support most or all camera features, including autofocusing and automatic exposure control. But adapters provide access to even more lenses, specifically those not available in mounts for the camera in question.
The recent rise of the mirrorless, interchangeable-lens camera has made lens adapters even more popular—partly because some of the mirrorless camera makers don’t offer a wide range of lenses for these cameras yet (nor do the independent lens makers) and partly because it allows use of higher-performance lenses not currently offered for their mirrorless systems.
Mirrorless camera makers are aware of the benefits an adapter can bring to the party. Sony offers adapters that permit use of lenses for the company’s DSLR cameras (as well as legacy Konica Minolta Maxxum lenses) on their NEX mirrorless cameras, greatly expanding the lens lineup. The recently introduced LA-EA2 adapter not only permits using these DSLR lenses, but it also incorporates a quick phase-detection AF system similar to the one in Sony’s SLT-A65 translucent-mirror DSLR.
Olympus and Panasonic offer adapters that let you mount standard Four Thirds System lenses on their Micro Four Thirds System mirrorless cameras, retaining the cameras’ contrast-based autofocusing with many of them. And Samsung offers a K-mount adapter that lets you use the wide range of Pentax K-mount lenses with its mirrorless NX cameras.
FLANGE BACK DISTANCE
This odd-sounding term refers to the distance between the lens mount and the image plane in the camera (the image sensor in a digital camera). Each camera manufacturer designs its DSLRs or mirrorless cameras with a specific flange back distance. If you wish to use a lens made for another camera on your camera, you have to consider this distance.
If the flange back distance of your camera is smaller than the distance for which the lens was designed, that’s not too bad. The appropriate adapter generally will make up the difference, and if it doesn’t, the worst that can happen is the lens will be able to focus "beyond infinity."
Problems arise when the flange back distance for the lens and adapter is greater than that of the camera. In that case, the lens won’t focus all the way to infinity. You can use it for closer work, but not for landscapes and other distant subjects. Some adapters include an optical element to permit focusing to infinity, but generally this also reduces image quality.
The mirrorless, interchangeable-lens cameras have very short flange back distances because they don’t have the bulky mirror box found in DSLRs. So these cameras can be used with any lens for which an adapter can be found—including lenses from old film SLRs.
DSLRs and mirrorless cameras provide full automation when you use lenses designed for them. You get autofocusing and open-aperture, through-the-lens metering. Be aware that some adapters interfere with these functions. And, of course, if you’re attaching a manual-focus lens such as a Leica or Zeiss, you won’t get autofocusing.
The focusing screens in DSLRs weren’t designed for manual focusing and lack the focusing aids found in manual-focus SLRs (central split-image and microprism collars on ground-glass focusing screens, for example). Some higher-end DSLRs accept interchangeable focusing screens; if you intend to use manual-focusing lenses with one of these, it’s a good idea to buy and install a screen that was designed for manual focusing.
With live-view cameras (many DSLRs and all mirrorless, interchangeable-lens models), you can zoom the live image and focus right on the LCD monitor. A magnifying loupe (and a tripod) can be very helpful here.
Some adapters come with chips that activate an AF DSLR’s focus-assist system, so the "in-focus" lamp in the viewfinder will glow when you’ve achieved focus manually.
When you use a DSLR with a lens designed for it, you get open-aperture metering. This means that, regardless of the aperture you select for a shot, the lens remains wide open until the instant of exposure, when it stops down to the selected setting. This provides the brightest image for composing and focusing. Most lens adapters break the linkage between camera body and lens that does this, so you’ll have to open the lens to its widest aperture to compose and focus, then manually stop the lens down to the desired shooting aperture before making the shot. This can be a problem with action subjects and with lenses that change focus when stopped down. And, of course, it can’t be done with lenses that don’t have aperture rings, like Canon’s EF and Nikon’s G series.
Canon EOS DSLRs and EF lenses have all-electronic lens mounts, where all communication between camera and lens is electronic; there’s no mechanical linkage aside from the bayonet mount that holds the lens on the camera. Thus, you can’t adjust the aperture when using an EF lens on a non-EOS body. However, Redrock Micro offers the LiveLens MFT Active Lens Mount, which lets you attach EF lenses to Micro Four Thirds System cameras and incorporates a battery-powered onboard electronic system that allows you to adjust apertures of EF lenses in 1?3- or 1?5-stop increments (but you must do this via the Redrock unit, not via the camera body).
Some adapters from Novoflex incorporate an aperture-control ring so you can adjust apertures with lenses that lack one, such as Nikon’s G-series.
Here’s a rundown of some sources of lens adapters for mirrorless, interchangeable-lens cameras and DSLRs.
Adaptimax provides adapters for pro video cameras, but includes adapters to attach Canon EF and Nikon SLR lenses to Micro Four Thirds System mirrorless cameras. www.adaptimax.com
Among Adorama‘s wide range of adapters is the Flashpoint Tilt Adapter for Nikon Lens to Micro 4/3. Besides allowing you to mount Nikon lenses on Micro Four Thirds System cameras, this adapter allows you to tilt the lens 12° in any direction thanks to 360° rotation capability. www.adorama.com
CameraQuest distributes an extensive range of adapters to mate DSLR and mirrorless Micro Four Thirds and Sony NEX bodies with a wide range of lenses. The website also includes lots of good adapter information. www.cameraquest.com
Dot Line offers an extensive line of adapters to attach SLR lenses to DSLRs and Micro Four Thirds and Sony NEX mirrorless cameras. www.dotlinecorp.com
Fotodiox markets a good selection of adapters for DSLRs and Micro Four Thirds and Sony NEX mirrorless cameras. www.fotodiox.com
Lensbaby offers a series of versatile special-effects devices. The Composer with Tilt Transformer comes with the popular Double Glass Optic and is compatible with the Lensbaby Optic
Swap optics. It also will accept Nikon-mount lenses, allowing you to use those lenses on Panasonic Lumix G, Olympus PEN and Sony NEX mirrorless cameras, with tilt capability in any direction. www.lensbaby.com
Novoflex provides a wide range of adapters, including some to fit medium-format lenses to SLR and rangefinder cameras, and to fit popular SLR lenses to mirrorless cameras. www.hpmarketingcorp.com
Olympus offers adapters to use Four Thirds System lenses on Micro Four Thirds System cameras, as well as old manual-focus Olympus Zuiko OM-system lenses on both Four Thirds and Micro Four Thirds System cameras. With Four Thirds System lenses that are compatible with contrast-based autofocusing, AF capability is retained. www.olympusamerica.com
Panasonic offers adapters to mount Four Thirds System and Leica M- and R-mount lenses on Micro Four Thirds System cameras, while retaining most, if not all, camera features. www.panasonic.com
Redrock Micro offers the LiveLens MFT Active Lens Mount, cited earlier, which mounts Canon EF lenses on Micro Four Thirds System bodies and provides precise control of aperture. www.redrockmicro.com
Samsung offers an adapter to mount K-mount lenses on its NX-series mirrorless cameras. www.samsung.com
Sony provides the LA-EA1 adapter to mount Sony Alpha-mount DSLR lenses (and legacy Minolta Maxxum lenses) on its NEX mirrorless cameras; the new LA-EA2 adapter provides its own phase-detection AF system. www.sonystyle.com
Voigtländer makes lenses and adapters, including adapters for Micro Four Thirds and Sony NEX mirrorless cameras. www.voigtlaender.de
Zörk offers adapters to mount medium-format lenses on 35mm and digital SLR bodies, plus adapters that provide shift and tilt capability with enlarger lenses on film and digital SLRs. www.zoerk.com