Sigma sd Quattro H Mirrorless Camera Body {45MP}

Sigma sd Quattro H: APS-H Foveon mirrorless for maximum detail purity.

The sd Quattro H is built around a 26.6 x 17.9mm APS-H Foveon X3 Quattro sensor, a stacked design that captures luminance data at 25.6 megapixels across its top layer, with color information gathered at two lower layers, eliminating the need for an optical low-pass filter. The result is a level of per-pixel detail that consistently outperforms conventional Bayer sensors of similar nominal resolution. At base ISO, files processed from the native X3F RAW format or DNG output carry a textural quality that reads as distinctly different from standard digital capture. Reviewers who tested it extensively confirmed that Sigma's claims about detail rivaling 50MP Bayer output hold up in real-world use.

The Dual TRUE III processor handles the complex per-layer deconvolution onboard, and DNG support means you can bring files into Lightroom or Capture One than relying solely on Sigma Photo Pro. The magnesium alloy body is splash- and dust-sealed, carries a 2,360,000-dot electronic viewfinder with 100% coverage, and pairs with the full SA Bayonet mount, giving access to Sigma's entire Art-series lens lineup. A hot shoe and PC sync socket make it at home in controlled studio lighting. The ISO range runs 100-6400, shutter speeds reach 1/4000 sec, and a ±5 EV exposure compensation range in 1/3-stop increments gives precise control over the sensor's narrow dynamic latitude.

Who It's For

Fine art and landscape photographers shooting at base ISO will get the most direct payoff from the Foveon's no-demosaicing detail capture and the absence of an optical low-pass filter. Studio portrait photographers benefit from the hot shoe, PC sync socket, and weather-sealed magnesium body, plus the 1.09x EVF magnification for careful composition under controlled light. Existing Sigma SA-mount lens owners can put their Art-series glass to immediate use without adapters. Photographers drawn to monochrome work gain from the sensor's full-luminance-per-pixel architecture, which produces black-and-white files with a tonal structure that Bayer sensors can't replicate without interpolation.

Key Features

• APS-H Foveon X3 Quattro sensor, 25.6MP luminance with dual 6.4MP color layers
• Dual TRUE III processor with onboard deconvolution to DNG
• 9-point hybrid AF (phase and contrast detection)
• 2.36M-dot electronic viewfinder, 100% coverage
• Magnesium alloy body, splash and dust sealed
• 1/4000 max shutter, ISO 100-6400, 3.8 fps burst
• SA Bayonet mount, full compatibility with 39 Sigma Art lenses
• Hot shoe and PC sync socket for studio flash

FAQ

What makes the Foveon X3 sensor different from a standard Bayer sensor?

The Foveon X3 Quattro captures luminance data (detail) at full 25.6MP resolution across its top layer, then gathers color information from two lower layers at 6.4MP each. There's no optical low-pass filter, so you get per-pixel detail without the softening that comes from demosaicing a Bayer array. The tradeoff is complex onboard processing to separate the color layers, which generates some noise, but the detail output at base ISO genuinely rivals 50MP Bayer sensors.

Can I use my existing SA-mount lenses on the sd Quattro H?

Yes. The sd Quattro H uses the full-depth Sigma SA Bayonet mount from Sigma's SLR line, so any of Sigma's 39 SA-mount lenses work directly. The camera includes phase-detection AF to help older lenses designed for DSLR focusing perform better than they would with contrast-detect only. If you mount an APS-C DC lens, the camera automatically crops the sensor to APS-C size and increases burst speed to 4.8 fps.

What's the dynamic range limitation I should know about?

The Foveon X3 Quattro has a narrower dynamic latitude than conventional sensors. You need to protect highlights carefully and expose thoughtfully, especially in contrasty light. This is why the camera includes ±5 EV exposure compensation and AE bracketing-use them. In studio or controlled lighting with proper exposure, it's not a practical constraint.

Does the sd Quattro H support DNG output so I can use Lightroom or Capture One?

Yes. The Dual TRUE III processor handles the per-layer deconvolution onboard and outputs DNG files directly, which both Lightroom and Capture One can open. You're no longer locked into Sigma Photo Pro, though you can still capture native X3F RAW if you want. Note that DNG and JPEG pairs aren't supported-you choose one or the other.

How fast is the autofocus, and will it work well with older lenses?

The sd Quattro H uses hybrid AF with both phase and contrast detection, which is faster than contrast-detect alone, but it's still not competitive with modern mirrorless cameras. Older SA-mount lenses optimized for DSLR phase detection will perform better here than they would on a contrast-detect-only body. Face detection is available but can be finicky. Manual focus with focus peaking (white, black, red, or yellow outline) is often the more reliable choice for critical work.

What's the battery life like?

Battery life from a single BP-61 battery is modest due to the complex Foveon processing. Sigma includes an optional PG-41 Power Grip that holds two additional batteries and should roughly triple your shot count. The grip also adds a vertical shutter release and redundant dials, making it practical for studio work where you'll have access to power anyway.

Does the sd Quattro H shoot video?

No. Like all Sigma Foveon cameras, the sd Quattro H is stills-only. It has no video capture of any kind, only live view on the LCD and electronic viewfinder.