sd Quattro H Review – Part 1

It came without surprise to many who know me as a strong advocate of Sigma cameras. I started using the dp Merrill back in 2013, which sets itself apart from other camera solutions as far as image quality is concern. The arrival of the dp Quattro changes the 1:1:1 3-layer sensor design to 4:1:1 which promises better image quality without sacrificing resolution and color definition. The sd Quattro arrived in early August, which addresses users’ need for an interchangeable lens mirrorless system which uses the same 19.5MP Foveon Quattro sensor as the dp Quattro. In February 2016, the sd Quattro was announced together with a higher end sd Quattro H camera body which sports a whopping 1.3x APS-H 25.5MP Foveon Quattro (4:1:1) sensor! No one has seen any sample images but after a 10-month long, the wait is finally over. The sd Quattro H is now available for sale in Japan and the rest of the world in weeks to come.

Image from Sigma Global website.

I am most fortunate to be given a production “H” just a few days before the official launch date. The “H” is largely the same as the “Q” externally except for the logo which differentiates them. Operationally both cameras are also the same including the user interface sans the newer features on the H.

The new sensor is slightly larger than the Q sensor, and it packs in a 30% increase in megapixels (6MP). The size of the pixel/sensel remains the same. Comparing the Q and H is not as straight forward because the focal length of each lens is now multiplied by a factor of 1.5X (Q) and 1.3X (H) respectively. The depth of field is also reduced on the H at a given aperture. It is closer to the rendition of a full frame camera, about half a stop.

For example, a 35mm lens produces a field of view of 52.5mm when used on the Q (1.5X), but it’s wider at 45.5mm on the H (1.3X). Similarly, the 50-100mm F1.8 DC HSM | Art becomes:

  • Q: 75mm to 150mm, F1.8
  • H: 65mm to 130mm F1.8

To make a fair comparison, one has to match BOTH the field of view AND effective aperture to gain a good understanding of the quantitative and qualitative differences between the Q and the H. Also, the H image file (6192 X 4128 pixels) will have to be downsampled to Q resolution (5424 X 3616 pixels) for a fair comparison. You will clearly noticed a remarkable difference in better rendering and resolution of diagonal lines and minute details on the H.

(Both images were taken from the same camera, one in DC Crop Mode to simulate the sd Quattro, and the other with the mode turned off. This is to ensure that the delay and framing between shots were mitigated or eliminated).

The increase in resolution results in better definition, separation and refinement in details which is apparent on print and display. This a clear advantage since the Foveon sensor is all about pursuing realism.


Shot with 8-16mm F4.5-5.6 DC HSM.

It is interesting to note that the image circle of the 8-16mm lens covers the APS-H sensor from 10mm onwards!

Shot with 50-100 F1.8 DC HSM | Art.

No problem using this lens with Crop Mode turned off.

Shot with 18-35 F1.8 DC HSM | Art.

The 18-35mm Art lens suffers from a degradation in corner sharpness without Crop Mode.

Shot with 18-35mm F1.8 DC HSM | Art in Super Fine Detail Mode.

Super Fine Detail (SFD) mode has been improved to reduce movement artifacts (with jagged edges). It seems to have an anti-ghosting algorithm to take care of those. It is now a lot more usable than before.

A 32″ wide print was made with this image, and the result is very impressive despite the fact that the corners of the image are soft when used without Crop Mode.

The support for DNG is the next big thing in my discussion in another blog entry together with the improvements in Sigma Photo Pro and Capture Pro. The improvements on the H shall be make available on the sd Quattro and the whole range of dp Quattros, as far as I was told.