What Hath Sigma Wrought?

analysis Feb 25, 2016

What Hath Sigma Wrought?

On February 22, 2016, Sigma Photo of Japan formally announced their entry into the mirrorless interchangeable lens camera market. They introduced not one, but two camera models: the SD Quattro and the SD Quattro H.

sd Quattro System

Not only did they introduce two mirrorless camera models, they introduced an entire camera system with some very professional looking specifications. A magnesium based body that is sealed against splashes and dust, two sensor sizes: APS-C (sd Quattro) at a 1.5x crop factor sporting 29 megapixels and APS-H (sd Quattro H) at a 1.3x crop factor sporting 45 megapixels, a battery grip that adds two additional batteries effectively tripling the battery life of the camera, a very nice speed light flash with a guide number of 63, on sensor AF using hybrid phase detect and contrast detection, and compatibility with Sigma’s entire line of SA mount lenses.

Wait a minute…

Yes, you heard me correctly: this camera mounts DSLR lenses natively. Sigma has made some very interesting design decisions with the sd Quattro cameras. Here are some of the highlights:

  • Mirrorless design that natively mounts DSLR lenses – the sd Quattro and sd Quattro H are both SA mount cameras which means they can take any of the Sigma DSLR lenses already made. This may sound like an odd choice as most mirrorless cameras sport very short flange distances and can use pretty much any lens with an adapter, but in this case Sigma decided to leverage its arsenal of new lens designs with having to create a new mount or mount adapter (like they did for Sony E-mount). Korean lens maker Samyang does this a lot with their lenses. The mirrorless versions are usually longer than their DSLR counterparts as they have permanently bolted an adapter on the back of the lens, which kind of kills the mirrorless design ethic. The sd Quattro and sd Quattro H therefore have the adapter included in their body design. To wit: sd Quattro H Bottom View The only drawback to this is that the sd Quattros cannot easily adapt legacy lenses.
  • This is not a small camera – Unlike most other mirrorless cameras, the sd Quattro are big. Even bigger than the Leica SL. Add the grip and this camera will go toe-to-toe with any other full-bodied professional DSLR. Camera Sizes This image shows the sd Quattro H on the left, the Leica SL in the middle and the Olympus Pen-F on the right. All three cameras are sporting fast 50mm lenses (or their native equivalent). The sd Quattro is even larger than the Leica SL and absolutely dwarfs the Olympus Pen-F. Mount one of Sigma’s big lenses on it and you will have yourself a kaiju-sized mirrorless rig.
    sd Quattro H + 500mm f/4.5 APO HSM
    Bring a monopod.
  • Dual Rear Displays – The back of the sd Quattro actually sports two displays: a 3″ main display and a smaller display right next to it showing important system parameters. This is a very interesting choice as it puts all of the pertinent information in one place as opposed to having the secondary display on the top of the camera. sd Quattro displays
  • Foveon Quattro Sensor – Sigma digital cameras do not use standard Bayer-type sensors. Several years ago Sigma purchased sensor start-up Foveon lock, stock and barrel. The Foveon sensor captures red, green and blue color information at every pixel site and thus does not require interpolation to calculate a color image. The Quattro design refines this technology even further. The result is super sharp images with an extremely high level of color fidelity. The drawback is that Sigma has not chosen to share the conversion algorithms with any other software maker so users are forced to convert RAW files using the free Sigma Photo Pro software. This will add another step in your existing workflow as the Sigma Photo Pro software is pretty basic.

Preliminary Conclusion

Not having personally handled the camera, I cannot give you any impressions as to its balance and overall ergonomics. If the sensors in these cameras are anything like the Quattro sensors in the DP series, you can expect very spectacular imagery out of them. For now I will give you my shortlist of pros and cons:


  • Fully baked system at launch. Cameras, lenses, flash and other accessories will ship with the cameras.
  • Complete line of lenses. By using the Sigma SA mount, the sd Quattros have a large selection lenses to choose from. Especially the newer Art, Contemporary and Sport lenses.
  • Solid Build. At least on paper. Preliminary reports from sites attended the CP+ show are confirming this.
  • Weather sealed. This does not mean waterproof. Do try to keep it dry anyway you can.
  • Large sensor. While not full-frame like the Sony A7 series, the sd Quattro has an APS-C sized sensor and the sd Quattro H has an APS-H sized one.
  • High pixel count. According to Sigma, the sd Quattro produces a 30 megapixel image while the sd Quattro H produces a 45 megapixel image.


  • Big. and likely heavy compared to other mirrorless system cameras.
  • Limited Adapter use. The built-in lens tube pretty much locks in the camera to SA-mount lenses. Sigma offers a mount conversion service for your existing Sigma lenses.
  • Weak software. Let’s face it: SPP is not Adobe Lightroom nor is it Capture One Pro. It is a basic converter used to turn your raw X3F files into TIFFs for editing in Lightroom, Capture One Pro or Photoshop.