Sigma fp introduction

Well we didn't see that one coming! Sigma has just announced the 'fp,' the world's smallest full-frame camera and, despite owning the sensor design company Foveon, it's built around a conventional Bayer sensor.
But, more than just being small, it's one of the most radical cameras we've seen released in years, incorporating an array of new ideas and video capabilities. We're at the launch event in Tokyo, where we've had a chance to use one.
The camera we handled is running fairly early firmware (v0.02) so it's too early to talk about performance, but it's immediately apparent Sigma's engineers have put a lot of work into making the fp a camera that's as practical as it is innovative.
The camera

The Sigma fp stands for 'fortissimo pianissimo,' which roughly translates as 'very loud and very soft.' This could be a reference to dynamic range but we also wonder if there's an intentional implication of the camera being both large (in terms of sensor) and small in its physical presence. Sigma also talks about the ability to be a 'compact daily camera' but also one that supports 'professional cine filming.'
It's built around a 24MP BSI-CMOS full frame Bayer sensor, which immediately makes it likely that it's a similar chip to the one used in the likes of Sony's a7 III, Nikon's Z6 and Panasonic's S1 (though we'll need to test images from the camera to be sure). There's no anti-aliasing filter, which is a little unusual at this resolution on full frame.
But the main thing you notice is that the fp is really small. It's a cuboid box with very few protrusions that measures just 113 70 45mm (4.43 2.75 1.78"). Part of the way it manages to be so small is that it lacks a mechanical shutter, instead relying entirely on the sensor's electronic shutter mode.
It can shoot at up to 18 fps (though only for 12 frames).
The body

The body of the fp has a certain functional charm to it. Despite its small size, it finds room for an array of control points and connectors.
In terms of controls, the top-plate features a shutter button set in the middle of the camera's main control dial, there's also a dedicated video [REC] button, a power switch and a dedicated Stills/Cine switch, which gives hints about the camera's intent.
The back of the camera finds room for nine buttons and a second control dial. The button functions include a conventionally-placed AEL button and a 'QS' button for accessing Sigma's 'quick set' menu.
The majority of the space is taken up by a large 3.2" 2.1M-dot touchscreen, behind which you can just make out the vents and fins of the heat sink built onto the back of the main processor board.
The body: connectors

In terms of connectors there are Mic, USB-C and HDMI connectors down the left flank of the camera. The USB-C port can be used to connect to an external SSD for video capture and the camera can be powered via the port, for longer periods than the battery allows.
All these ports sit behind large rubber doors, to contribute to the camera's extensive weather sealing.
The camera's strap lugs screw into tripod-style 1/4" treaded holes on either side of the body, meaning they can be removed if you want to mount the camera vertically on your tripod (or re-arrange your camera strap, however you want).
Included with the camera is a screw-on adapter that adds a flash hotshoe and also acts as an HDMI cable retainer/protector. This hotshoe mount can, of course, be used to mount an external microphone for video work.
Two optional hand grips (the HG-11 and HG-21) will also be offered, providing different degrees of extension to provide a more firm grasp on the body (particularly for use with larger lenses).
Stills and focus

The camera shoots both JPEGs and DNG Raw files. The Raw files feature lossless compression and can be captured in with 14 or 12-bit definition.
The fp is entirely based around contrast detection autofocus but includes a Face and Eye detection, to make it easier to shoot portrait images. It's too early for us to form impressions of the camera's AF speed, but we're very interested in testing that as soon as we can.
Image processing

Sigma has clearly given a lot of thought to image processing on the fp. It includes the ability to re-process Raw files in the camera, including the ability to apply the shadow-lifting 'Fill-Light' processing previously only available in its Sigma Photo Pro software.
The camera also includes an unusual 'Teal and Orange' color mode designed to mimic the look that's become popular in Hollywood movies.
In addition, the Sigma fp can generate 'Cinemagraphs' - animated GIFs in which part of the image moves while the rest stays static. This is the first time we've seen this feature built into a camera.

Video is a core feature of the fp. The camera allows the capture of MOV processed video with either Long GOP or ALL-I compression, but the unusual feature is its ability to capture and output CinemaDNG Raw video footage.
It can shoot UHD 4K at a choice of 29.97p, 25p or 23.87p or 1080 footage at up to 119.88p.
The CinemaDNG footage can be captured internally 8 or 10-bit quality in 30p and 25p mode, or 12-bit quality for 24p shooting. Data can also be output to external SSDs. The camera's HDMI v1.4 connector almost certainly means it won't output Raw footage over that port, though the fp is compatible with Atomos' open HDMI protocol, meaning recording can be started or stopped from the external recorder.
Impressively, it appears that Sigma has designed a distinct video interface for the fp that lets you specify the shutter duration in terms of shutter angle and also includes a small waveform display, to let you set exposure and check the tonal distribution in your frame. The fp will also gain, via firmware, the ability to simulate the aspect ratios of various pro video platforms, to help you mimic the framing of cameras including a variety of Arri and Red cameras.
Using the optional CN-21 DC connector allows the fp to be powered from an AC power adaptor or a V-mount battery plate.
Flash and rolling shutter

The obvious challenge of basing a camera around an electronic shutter is that most sensors suitable for high-end photography take some time to read out their data, which limits the maximum speed of their electronic shutter mode.
This has two main consequences: firstly it leaves the risk of rolling shutter distortion if your subject moves as the sensor is being read (this also presents a challenge under artificial light sources, where the lights become brighter and darker during the exposure, leaving dark bands across the image).
The second issue is that it significantly limits the ability to use the camera with flash (if the sensor takes a long time to read-out, you can only fully expose the sensor at long exposure times). So, although Sigma showed the fp with an external flash mounted, it says the maximum sync speed is 1/30 seconds (this drops to 1/15th in 14-bit Raw mode).
In announcing the camera's development, Sigma CEO Kazuto Yamaki acknowledged the rolling shutter effect but said 'the sensor used has a very fast reading speed. It is able to shoot without major problems in most shooting scenes.'
Lens mount

The fp is built around the Leica-developed 'L-mount.' Alongside the camera, Sigma showed off the first three mirrorless-specific 'DN' lenses it's developed for the L-mount. These included a compact 45mm F2.8, which pairs nicely with the fp.
In addition, Sigma has already announced that it will make adapters that allow Canon EF lenses to be adapted. And, for existing Sigma users, an adapter for its own SA-mount lenses.
First Impressions

As we say, the fp we had a chance to use was running very early firmware, so it's difficult to read too much into its performance at this stage. That said, our initial impression is that autofocus seems reliable and repeatably accurate in S-AF.
What we can say is that it behaved pretty well, considering its state: it booted up quickly and the touchscreen was fairly responsive. The menu system (seemingly evolved from the one on the SD Quattro modes) looks pleasantly simple and pared-down.
As you'd expect of a camera with a heat sink with vents around where you hold it, we found it got warm in use, but not worryingly so. Sadly it's too early to assess battery life, but none of the demonstration units ran out during our time with them. The use of a decently large 8.7Wh battery should help in this regard.
The camera seems extensively thought-through, not just in terms of offering plenty of options about what the dials control, but also in the small details like letting you choose auto, faster and slower shutter thresholds in Auto ISO mode, that relate to the focal length you're currently using. This is the kind of fine-grained detail that major camera makers don't always get right.
It definitely suggests Sigma has put a lot of work in, before taking the wraps off its little box of tricks.