FUJIFILM GFX Tech Info
Fuji GFX 50S Review -- Technical Info
by Mike Tomkins
The Fuji GFX 50S sports a brand-new medium-format, mirrorless camera body crafted from magnesium alloy. According to Fuji, its choice of a mirrorless design allowed a one-third reduction in weight, as compared to a similar camera with a DSLR design and the same sensor size.
The GFX 50S body is weather and dust-resistant, and freezeproof to allow use in temperatures as low as 14°F (-10°C). Dedicated dials are provided for shutter speed and ISO sensitivity control on the camera body itself, while there's a ring dedicated to aperture control on all GFX lenses.
Each of these controls also has an Auto position, so you can attain fully-manual control by switching all three to their Auto positions, then return to priority or manual control by switching some or all of the controls back away from their Auto positions.
And if you prefer the more commonplace front-and-rear dial control over exposure used by most cameras, the Fuji GFX 50S can also function in that manner if you switch over to command dial operation.
At the heart of the Fuji GFX 50S is a 4:3-aspect, medium-format CMOS image sensor with dimensions of 43.8 x 32.9mm, referred to by the company as the Fujifilm G format. The sensor has an effective resolution of 51.4 megapixels, and a standard Bayer RGBG color filter array. Output image dimensions are a maximum of 8,256 x 6,192 pixels. The total pixel count had not been disclosed.
According to Fuji, the sensor itself is an exclusive, indicating that the precise design hasn't been used previously, although it could still be related to an existing chip such as the similarly-specified Sony sensor used in the Pentax 645Z.
As well as its native 4:3 aspect ratio, the Fuji GFX 50S also allows users to shoot with a choice of 3:2, 16:9, 1:1, 65:24, 5:4 or 7:6 aspect ratios. As compared to a 35mm full-frame sensor, the Fuji GFX 50S image sensor has 1.7x the surface area, allowing it to gather significantly more light.
Output from the GFX 50S' new image sensor is handled by Fujifilm's proprietary X Processor Pro image processor, as featured previously in the X-Pro2 and X-T2 cameras.
As is typical of medium-format cameras, the Fuji GFX 50S has rather sedate performance. Burst capture is possible at either 1.8 or 3.0 frames per second, depending upon whether or not you opt for its electronic first-curtain shutter function.
At the higher rate, Fujifilm claims the GFX 50S can capture eight uncompressed RAW or 13 losslessly compressed RAW frames in a burst. In the lab, the GFX was able to capture up to 21 lossless compressed RAW files, but the number uncompressed RAW files matched Fujifilm's spec. At the lower rate, the uncompressed RAW burst depth is unchanged, but losslessly compressed RAW files can be shot for as long as sufficient card space and power remain. The same is also true of JPEG capture at either rate, however in the lab the GFX managed 40 best quality JPEGs before slowing. See our Fuji GFX Performance page for details.
The Fuji GFX 50S provides a generous default sensitivity range of ISO 100 to 12,800-equivalents, and this can be expanded to encompass everything from ISO 50 to 102,400 equivalents if image quality isn't your overriding concern.
The GFX 50S debuts a new Fujifilm G lens mount with a flange-back distance of 26.7mm.
At launch, three optics were available for the Fuji G mount. These were the GF63mmF2.8 R WR, the GF32-64mmF4 R LM WR, and the GF120mmF4 R LM OIS WR Macro. Two additional models were launched later in 2017: the GF110mmF2 R LM WR and the GF23mmF4 R LM WR. A sixth lens, the GF45mmF2.8 R WR, should be available before the end of the year. Fujifilm also plans on launching a telephoto prime as well as a teleconverter in 2018.
According to Fuji, all G-mount optics are designed to be capable of resolving detail sufficient for a 100-megapixel image sensor, far in excess of the GFX 50S' actual 51-megapixel resolution. They also all feature dust, weather and freeze-proofing to the same degree as the GX 50S camera body, as well as hydrophobic fluorine coatings to protect their front elements. And as noted previously, all Fuji GF lenses also include a dedicated aperture control ring. This has a locking function to prevent accidental changes, and offers up Auto and Command positions, the latter used if you prefer to control aperture from the camera body rather than the lens ring.
The GF23mmF4 R LM WR super-wide angle prime lens has a 15-element, 12-group design with two aspherical, one super extra-low dispersion and three extra-low dispersion elements, and has an 18mm equivalent focal length. Dimensions are 4.1 x 3.5 inches (103.0 x 89.8mm), and the 23mm prime weighs in at around 29.8 ounces (845g). List price is around US$2,600.
The GF63mmF2.8 R WR prime lens has a 50mm equivalent focal length, a 10-element, eight-group design with one extra-low dispersion element, and uses the front group for focus control. Dimensions are 3.3 x 2.8 inches (84 x 71mm), and the 63mm prime weighs in at around 14.3 ounces (405g). List price is around US$1,500
The GF32-64mmF4 R LM WR zoom lens, meanwhile, has a more complex 14-element, 11-group design with three aspherics, one ED lens and one Super ED lens. It has an internally-focusing design with linear AF motor and has a 35mm-equivalent focal length of 25-51mm. Dimensions are 3.6 x 4.6 inches (92.6 x 116mm), and the 32-64mm zoom weighs in at around 30.8 ounces (875g). List price is around US$2,300.
The GF110mmF2 R LM WR prime lens has a 14-element, 9-group design with four ED elements, and is designed for portraits with an 87mm equivalent focal length and a fast f/2.0 maximum aperture. Dimensions are 3.7 x 4.9 inches (94.3 x 125.5mm), and the 110mm prime weighs around 35.6 ounces (1010g). List price is around US$2,800.
Finally, the GF120mmF4 R LM OIS WR Macro prime lens has a 14-element, 9-group design with three ED elements, and includes optical image stabilization with a claimed five-stop corrective strength. Maximum reproduction ratio is 0.5x and the 35mm-equivalent focal length is 95mm. Dimensions are 3.5 x 6.0 inches (89.2 x 152mm), and the 120mm prime weighs around 34.5 ounces (980g). List price is around US$2,700.
To help combat the effects of dust adhering to the image sensor's cover glass, Fujifilm has included an ultrasonic dust removal system in the GFX 50S.
Since the Fuji GFX 50S is a mirrorless camera, it must forgo a true optical thru-the-lens finder. In its place is an electronic viewfinder based around a 0.5-inch, 3.69-million dot Organic LED panel. Eyepoint is 23mm from the eyepiece lens, and there's a claimed 100% coverage with 0.85x magnification (50mm lens at infinity and -1 diopter adjustment dialed in). The diopter correction, incidentally, has a -4 to +2 diopter working range.
A proximity sensor is built in to allow the camera to automatically enable or disable the viewfinder as needed when you raise it to your eye or lower it again. The GFX 50S viewfinder is also detachable if you prefer to travel light and shoot using the LCD monitor instead, and can be supplemented by mounting it on top of the optional EVF-TL1 tilt adapter, which allows 90-degree vertical tilt and 45-degree rotation.
The Fuji GFX 50S includes two built-in displays, one in color on its rear panel, and another being monochrome and located on the top deck.
The rear-panel display has a 3.2-inch diagonal and a 4:3 aspect ratio, and offers up a total of 2.36-million dot resolution. It has a claimed 100% coverage, and has a tilting design as seen previously in the X-T2. This allows not just tilting up and down in landscape orientation, but also tilting upwards when shooting in portrait orientation. (Here, it can't be tilted downwards but you can achieve the same thing by simply rotating the camera itself by 180 degrees to aim the display downwards.)
There's also a touch-sensitive overlay, allowing the rear-panel display to be used to control autofocus point selection, menus and the camera's playback mode, where you can use much the same gestures that you would to browse images on your smartphone.
The smaller 1.28-inch top-deck display, meanwhile, serves to show exposure variables and the like. It has a dark background with lighter text color, and can be viewed in the dark too courtesy of an adjacent illumination button. This display remains active even when the camera itself is powered off, and the resolution is 128 x 128 pixels with a 1:1 aspect ratio.
Exposures are determined using the image sensor, with the Fuji GFX 50S using a 256-zone metering system. As well as the default multiple metering, a choice of spot, center-weighted and average metering modes are also provided.
To help push the exposure in your chosen direction, Fuji has also included a healthy +/-5 EV of exposure compensation, set in 1/3 EV steps. For movie capture, there's a more abbreviated +/-2 EV exposure compensation range. You can also bracket exposures within a +/-3 EV range in 1/3 EV steps, with a total of two, three, five, seven or nine frames in each bracketed series.
Autofocus, too, is handled by the image sensor. The Fuji GFX 50S has a 117-point contrast detection autofocus system at the standard point size, with a grid of 13 x 9 focus points, although this can be increased to 425 points (25 x 17 grid) at the smallest AF point size. In total, you can select from six AF point sizes. There are also 3 x 3, 5 x 5 and 7 x 7 zone AF modes on offer when using the 117-point mode, as well as nine-point wide / tracking AF. And of course, you have a choice of single or continuous-servo AF operation.
The active focus point can be selected either using the touch-panel overlay on the rear of the camera, or using the same focus lever control as seen previously on the Fuji X-Pro2. And it's worth noting that since it doesn't have to rely on an external autofocus sensor, the GFX 50S' autofocus system shouldn't be prone to slight front- or back-focus concerns as can happen on cameras which must rely on a separate AF sensor, such as the Pentax 645Z.
The Fuji GFX 50S offers up a selection of program, aperture-priority, shutter-priority or manual shooting modes. Shutter speeds from the mechanical focal-plane shutter range from 60 minutes to 1/4,000 second, plus a bulb mode which is also limited to 60 minutes or less. Program autoexposure is limited to a maximum of four seconds, while at the other end of the range an electronic shutter function can manage exposures as swift as 1/16,000 second. X-sync is at 1/125 second or slower.
A total of ten white balance modes are on offer, including auto, seven presets including underwater, plus custom and kelvin modes.
As noted previously, flash X-sync is at 1/125 second or slower. There is not surprisingly no built-in flash in this pro-oriented model, but a hot shoe and sync terminal are both provided for external strobes. Both first and second-curtain sync are available, along with Auto FP (high-speed sync).
The Fuji GFX 50S includes the company's clever Film Simulation modes. These are applicable both for still and video capture, and in total your choices are for Standard, Provia, Velvia, and Astia film looks, plus Classic Chrome, PRO Neg.Hi, PRO Neg.Std, Black&White (optionally with yellow, red or green filters), Sepia and Acros (with optional yellow, red or green filters). Grain and color effects can be enabled separately, and a two-step strength control is available. If you prefer, you can also bracket any three film simulation types, and bracketing is also available for white balance, ISO sensitivity, dynamic range and exposure.
If you want to get yourself in the picture or just avoid camera shake when shooting tripod-mounted, both two and 10-second self-timers are available. An interval timer function is also included, with programmable start time, interval from one second to 12 hours, 59 minutes and 59 seconds, and number of shots up to 999 frames.
Although the focus is clearly on its still imaging capabilities, Fujifilm has nonetheless included video capture on the feature list for the GFX 50S. You can record movies at either Full HD (1,920 x 1,080 pixel) or HD (1,280 x 720 pixel) resolution, and have a choice of 29.97, 25, 24 or 23.98 frames per second capture rates.
H.264 / MPEG-4 AVC compression is used, and movies are stored in a .MOV container with 48KHz linear PCM stereo audio. Full HD movies have a 36Mbps bitrate, while HD movies have an 18Mbps bitrate, and both are limited to 30 minutes per clip maximum.
The Fuji GFX 50S includes dual SD card slots, and can use the secondary slot as an overflow for when the first slot is filled, as a backup of the card in the first slot, or to segregate images with RAWs on one card, and JPEGs on the other.
Both slots are compatible with the higher-capacity SDHC and SDXC card types, as well as with the higher-speed UHS-I and UHS-II card types. You can also select whether to use losslessly compressed or uncompressed 14-bit .RAF RAW files, and can choose from one of three JPEG compression levels. TIFFs can't be captured natively, but you can convert RAW images to 8-bit TIFFs in-camera.
The Fuji GFX 50S includes a generous selection of wired and wireless connectivity options.
Wireless connectivity includes support for 802.11b/g/n Wi-Fi networks in infrastructure mode using WEP, WPA or WPA2 encryption, and allows for remote shooting, geotagging by piggybacking off your phone's GPS receiver, printing using Fuji's Instax Share tech, and image transfer.
Wired options include USB 3.0 High Speed data using a Micro USB terminal, a Type-D Micro HDMI video output, dual 3.5mm jacks for microphones and headphones, a 2.5mm remote release connector, hot shoe and flash sync terminal, and a 15-volt DC input. The Micro USB terminal is also compatible with an optional RR-90 remote release, and tethered shooting from a PC is supported.
Power comes courtesy of a new 10.8V 1230mAh NP-T125 lithium-ion rechargeable battery pack. Fuji says that this is sufficient for 400 shots on a charge when using the GF63mmF2.8 R WR lens and either the LCD or EVF with the GFX 50S' Auto Power Save function is enabled. With Auto Power Save disabled, that number drops to 340 shots.
Several optional accessories are available for the Fuji GFX 50S, including the VG-GFX1 vertical battery grip, EVF-TL1 EVF tilt adapter, H Mount Adapter G and View Camera Adapter G.
The VG-GFX1 battery grip offers duplicate controls for portrait-orientation shooting, and allows a second battery to be installed for roughly double the battery life. You can also charge a battery in the grip in two hours with an optionally-available AC-15V accessory.
The optional EVF-TL1 EVF tilt adapter, meanwhile, sits between the GFX 50S body and the included EVF accessory, and allows the finder to be tilted up to 90 degrees vertically, and swiveled +/-45 degrees horizontally.
Finally, the H Mount Adapter G and View Camera Adapter G allow use of historic glass on the GFX 50S body, a capability that will be particularly useful until Fuji has had sufficient time to build out its GF lens lineup. The H Mount Adapter G allows the use of a total of nine Super EBC Fujinon HC lenses and one teleconverter developed for the GX645AF medium format film camera using manual focus with flash sync speeds up to 1/800s, as well as the ability to adjust the aperture via the GFX's control dial when in manual or aperture priority mode. Electrical contacts permit lens-to-body communication for applying in-camera lens corrections and for recording metadata. Included with the adapter is a removable tripod foot. The View Camera Adapter G allows the GFX 50S to be used as a digital back by mounting the camera to the back of a 4x5 view camera body. The adapter is mounted in the film camera loading position of the view camera, and either the in-lens or in-body focal plane shutter can be used.