It’s the world’s smallest full-frame mirrorless camera by far, but does this mean it’s compromised in real-world use? Andy Westlake takes a detailed look
Sigma fp: At a glance
- £1,999 body only
- £2,399 with 45mm f/2.8 DG DN lens
- 24-million-pixel full-frame sensor
- ISO 6-102,400
- 18fps shooting
- 3.1in, 2.1m-dot fixed touchscreen LCD
- 4K video recording
Sigma is best known as one of the finest third-party lens makers, but it’s always had an interest in making cameras too. The firm long ago learned that there’s little point in competing directly with the likes of Canon and Nikon by making identikit DSLRs, so its digital models have always been slightly off the beaten track. It was the first to make a compact camera with a large sensor for higher image quality, with the DP1 in 2008, and has developed this concept ever since. Its latest model follows a similar theme, but takes another step up: it’s the world’s smallest interchangeable-lens camera with a full-frame sensor. The fp name comes from the musical notation ‘forte-piano’ meaning ‘loud and soft’, suggesting high performance in a discreet, unassuming package.
Indeed according to Sigma CEO Kazuto Yamaki, the design concept was very simple: to make the smallest possible full-frame camera for travel. To this end, the firm has removed everything but the essentials needed to make the camera work. So there’s no viewfinder, with just a fixed rear LCD for composing your images. The mechanical shutter has also been left out, leaving the camera reliant on an electronic shutter, and if you want to use an external flash, this requires bolting a hot-shoe adapter onto the side. Indeed the fp is designed to be modular, with the option to add various grips and accessories to meet each user’s needs. It’s a really interesting concept, and quite unlike anything else you can buy.
But just how small is the Sigma fp, really? The body is a rectangular box measuring 113 x 70 x 45mm, making it comparable to a Sony Alpha 7 III with the viewfinder removed from the top and the handgrip from the front, and 14mm taken off one side. It’s similar in size to compact APS-C models such as the Canon EOS M6 Mark II, Fujifilm X-T30, or Sony Alpha 6400. But of course you need a lens, with the matched Sigma 45mm F2.8 DG DN adding 46mm to the depth and giving a total weight of 640g. This combination is small by full-frame standards, but is still larger and heavier than the fixed-lens Sony RX1R II, which sports a 42.4MP full-frame sensor, 35mm f/2 lens, pop-up viewfinder and tilting screen, but costs £600 more.
Sigma fp: Features
As Sigma’s first camera born of its alliance with Leica and Panasonic, the fp is based around the mirrorless Leica L mount. Not only can it use native lenses from all three companies, but also adapted Canon EF or Sigma SA-mount lenses via the Sigma MC-21 adapter. Officially, only the firm’s Global Vision-series lenses made since 2012 are fully compatible with the MC-21, but in practice, every Canon EF lens I tried worked fine, although autofocus tends to be slow. As with all mirrorless cameras, a huge array of manual-focus lenses can also be used via mount adapters.
In contrast to all of the firm’s previous models, which used multi-layer Foveon sensors for full-colour sampling at each pixel location, the fp’s 24MP full-frame sensor employs a conventional Bayer colour filter array. This should massively broaden the fp’s appeal, as it delivers considerably higher dynamic range and lower high-ISO noise. The sensor employs a back-illuminated architecture to increase light-gathering sensitivity, while detail rendition is maximised by the omission of an optical low-pass filter.
The standard sensitivity range of ISO 100-25,600 is par for the course these days, as are the extended high settings up to ISO 102,400. But at the other end of the scale, Sigma has added a unique set of ‘composite’ settings down to ISO 6. Unlike on other cameras, these aren’t ‘pulled’ low ISOs with reduced highlight range; instead the camera takes a series of exposures at ISO 100 and adds them together. It’s a really neat trick that allows you to use long shutter speeds without needing a neutral density filter, while delivering raw files with ludicrous dynamic range that can easily be pushed five stops with no visible noise. The catch, as with other composite modes, is that anything moving within the scene will give multiple ghost images.
Autofocus uses contrast detection, with three different size AF areas that can be placed freely across approximately 80% of the frame width and 75% of its height. When moving the AF point using the physical controls rather then the touchscreen, it’s easiest to switch to a 49-point setup, arranged in a 7×7 grid. Naturally you can enable face- and eye- detection, at which point the camera will outline your subject and track them as they move around the frame.
In terms of shooting speed, the fp is capable of up to 18 frames per second, although with a buffer of just 12 frames. The shutter provides settings up to 1/8000sec, and being electronic, is entirely silent. Rolling shutter artefacts can be apparent if you pan the camera while shooting, but Sigma has done an decent job of suppressing the banding that can be caused by the flickering of LED or fluorescent lights when shooting indoors.
Raw files are recorded as 14-bit DNGs, so they should open easily in your existing raw converter, if perhaps without a perfect colour profile. Sigma has also included a good range of options for adjusting the camera’s JPEG colours, accessed using a dedicated button on the back. Alongside a conventional-sounding set of modes such as portrait, landscape etc, there are some more creative options with names like Teal & Orange, Sunset Red and Forest Green, each of which can be tuned in-camera.
Another button allows you to adjust the tone curve, with highlights and shadows set independently, and the impressive Fill Light feature familiar to users of Sigma’s raw processing software has been transposed into the camera itself. All of these options can also be applied retrospectively using the in-camera raw converter.
Other handy features include an intervalometer and a comprehensive array of bracketing options (exposure focus, white balance, colour mode and fill light). One thing that’s conspicuous by its absence, though, is any form of smartphone connectivity – neither Wi-Fi nor Bluetooth is included. Likewise image stabilisation needs to be provided by the lens: a form of electronic stabilisation is built-in, but only for JPEG shooters.
Videographers will find a lot to like, with the fp promising to be an excellent little camera for use in a rig or on a drone. It’s capable of recording 4K (3840 x 2160) video at 30 fps, and can output raw video in the 12-bit CinemaDNG format to an external recorder. One especially neat trick is that the camera can record directly to an external SSD, simply by plugging one into the USB-C port. This is such a useful idea that you have to wonder why the bigger camera firms haven’t adopted it before. The full scope of the camera’s movie capabilities goes far beyond what it’s possible to cover in a stills-focused review, but suffice to say, it has a lot of videographers very excited.
Sigma fp: Focal points
The compact-bodied, modular Sigma fp is quite unlike any other full-frame mirrorless camera.
- Sigma’s BP-51 battery is also used by the dp Quattro series, and is identical to the Panasonic DMW-BLC12, so spares are easy to find. It’s charged via the USB port, with a 1.8A supply included in the box.
- A large heat sink behind the LCD screen provides a means of preventing the camera from overheating during video recording.
- Along with the usual tripod thread on the baseplate, there’s another ¼ in socket on each side. They’re used for attaching accessories, handgrips and even the removable strap lugs.
- On the side you’ll find USB-C, microphone and micro-HDMI ports, alongside a connector for the add-on hot-shoe accessory. The mic socket also accepts the CR-41 cable release.
- The fp is designed to be dust- and splash-proof, with seals arranged at 42 points around the camera body.
- There’s a single UHS-II type SD card slot, but you can also record files to an SSD connected to the USB-C port, which should be especially handy for videographers.
- Color and Tone buttons on the back provide an access to a broad range of in-camera image-processing effects
Sigma fp: Build and Handling
When you first pick up the fp, it’s clear that this camera is built to withstand less-than-gentle conditions. Its die-cast aluminium body feels completely solid, and is sealed at 42 points against dust and moisture. The various buttons, dials and switches are large and well-spaced, and I rarely found myself operating anything inadvertently. Indeed despite the camera’s small size, it’s quite usable when you’re wearing gloves.
That brick-shaped camera body does, however, fit into your hand just as awkwardly as you might expect. It desperately needs something – anything – on the front plate to afford your fingers some purchase. Thankfully Sigma makes two accessory handgrips, with the smaller HG-11, which bolts onto the side of the body and wraps around the front and back, being the bare minimum you need. I used it as a matter of course with the 45mm f/2.8 and found it improved the handling immeasurably, the catch being that it adds £60 to the price. Meanwhile the larger HG-21 attaches to the baseplate, and is a better option with heavier lenses, but costs £100.
In contrast, the control layout and user interface is mostly excellent. Two large switches on top turn on the camera and select between the Still and Cine modes, with entirely independent settings and optimised interfaces for each.
A pair of electronic dials on the top and back set exposure parameters, with the rear one controlling exposure compensation in the P, A and S modes; however the dial functions can be exchanged if you prefer. This allows you to repurpose the larger top dial to exposure compensation when shooting with lenses that have physical aperture rings, such as the 45mm f/2.8. The rear dial also serves as a d-pad for navigating menus and changing settings.
Other key settings are changed using Sigma’s excellent onscreen Quick Set menu, which is accessed by a press of the QS button. Here you’ll find such things as ISO, white balance, metering and drive modes, along with image quality, aspect ratio and fill light options. There’s no exposure mode dial; instead this is changed using a button at the camera’s base.
On the whole, the controls operate with satisfying precision, aside from slightly ill-defined click-stops on the rear dial which can hinder changing settings quickly. Very little hardware control customisation is on offer, aside from defining whether the movie record button should be active in Still mode, and specifying how the AEL button should behave. But with an interface this well thought-out, you don’t necessarily need it.
One area where the fp is let down, though, concerns focus-area selection. Usually you’re expected to use the touchscreen, but when you tap on the subject, the response is disconcertingly laggy, with the camera taking almost a second to register the new AF point. Things are no better using the physical controls: you need to tap the down button of the d-pad, then AEL, and then use the d-pad, which is unnecessarily long-winded and requires a lot of thumb movement. It’s a shame the d-pad can’t simply be used to set the focus area directly.