Advances in tech often pave the way for physically smaller devices. Moore’s Law states that transistors in an integrated chip get smaller periodically, meaning we can theoretically pack more transistors that are both more efficient and powerful than their predecessors in a comparatively sized chip as time goes on. This affects all things electronics, and even more so in digital cameras. The first attempts at a full frame DSLR (like the Nikon E-series) were absolute bricks and had single-digit megapixel CCD sensors. Fast forward to 2021, and we have infinitely superior full frame cameras that are not too far off from your average iPhone in terms of size. Case in point: The Sigma fp.

The Sigma fp is the World’s Smallest Full Frame Camera

At the time of writing, the Sigma fp still holds the title of the world’s smallest full frame camera. It’s also the lightest full frame camera at only 370g (without the battery). The fp has a respectable 24.6-megapixel CMOS sensor, a 3.15-inch touch screen, and a reliable contrast-detection AF system. Finally, the Sigma fp is part of the L-Mount alliance so lens selection for this camera won’t be an issue. Checkout our round up of the best L-mount lenses according to pros if you’re looking to build your L-mount kit.

So far, the specs are looking great for the average photographer, especially when you consider its size. Without any accessories attached to the body, the Sigma fp is extremely compact. It comes in at 112.6 (width) x 69.9 (height) x 45.3 (depth) mm, even smaller the iPhone 12 in some places. To put things into perspective, here’s how it roughly compares to an entry level DSLR and an AA battery for scale:

But with a whole slew of features such as 4K recording, 12-bit CinemaDNG (RAW video), and a specially designed heat sink to prevent overheating issues over extended shooting periods, it’s easy to see how the fp will appeal more to video shooters.

However, this should not take away from it being an amazing stills photography tool — you just have to come into the system knowing full well you’ll need to work around some of its quirks. For one, the Sigma fp does not have a popup viewfinder like some compact cameras. If you really wanted one, you’ll have to get Sigma’s proprietary LVF-11 LCD loupe-style viewfinder. For any hopes of doing any flash photography, you’d have to get the side-mounted HU-11 Hot Shoe Unit which comes with a sync port. And in the very likely scenario that you find the Sigma fp’s brick design uncomfortable in the hands, you’ll have the choice between the standard HG-11 Hand grip or the larger HG-21 Large Hand Grip.

New York-based photographer Bjorn Petersen, in his first impressions of the Sigma fp, says “it’s just as good as any other full-frame 24MP camera out there” in terms of image quality. That shouldn’t be a surprise as Sigma opted for a more conventional CMOS sensor for their first full frame camera, instead of the rather exotic Foveon sensors found in their earlier cameras that had trouble in low light environments. Autofocus performance, while not at the level of bona fide sports shooters, will do just fine in most general shooting scenarios.

For the video side of things, where many in the community feel the Sigma will truly shine, the fp is shaping up to be a very competitive cinema camera. The Sigma fp produces gorgeous files with all the dynamic range you’d expect from RAW video. Its ridiculously small form factor should let filmmakers put together a camera rig small enough to fit tighter spaces for more creative shots. NoFilmSchool says the Sigma fp is the “’dream’ form factor (super tiny, massive sensor).” And at about 4.43 x 2.75 inches, there’s really no point in arguing that. Have a look at “sin-sin“, a moving short film shot on the Sigma fp.

Honorable Mentions

Sony RX1R II – This incredibly capable full frame compact camera from Sony comes as a close second to the Sigma fp in size. The Sony RX1R II is also quite the featherweight, coming in at just 507 g with the battery, and that’s with the fixed Zeiss 35mm f2 lens. With a pop-up OLED viewfinder, a fast 35mm lens, and the same 42-megapixel full frame sensor from the Sony A7r II, the Sony RX1R II does not compromise on performance. If you’re looking for or a high-resolution monster that you can just chuck in your travel bag and you’re happy with a fixed 35mm lens, the Sony RX1R II is an awesome choice.

At 113.3 x 65.4 x 72 mm, it’s ever so slightly larger than the Sigma fp. According to Camerasize.com, it’s only 1% (0.7 mm) wider, 6% (4.5 mm) shorter (not counting protrusions), and 54% (24.3 mm) thicker than the current smallest full frame camera in the world.

Leica Q2 – The next contender for the world’s smallest full frame camera title is another fixed-lens camera. Touted by many as the gateway drug to the world of Leicas, the Q2 is a premium compact camera with a fantastic 28mm f1.7 Summilux lens and an impressive 47-megapixel sensor. It takes a lot of design cues from any other Leica rangefinders, and at only 130 x 80 x 91.9 mm, this fixed-lens full frame camera is a dream to use in the streets.

Sony A7C – Yet another entry from Sony. The Sony A7C is more of your “traditional” interchangeable mirrorless system and the unassuming design won’t differentiate it from Sony’s APS-C lineup. But look closely and you’ll find a 24-megapixel full frame sensor from the Sony A7 III inside an A6000-series shell. It’s also got a fully articulating touchscreen which should make it attractive for content creators and vloggers. Sony also introduced the FE 28-60mm f4-5.6 featuring a retracting design which you can get as a kit lens for the A7C. At only 124 x 71.1 x 59.7 mm, the Sony A7C is the perfect choice for professionals looking for a compact, fully-fledged backup camera that won’t take too much bag space.