Sigma dp3 Quattro 50mm f/2.8: Only One of its Kind

Sigma dp3 Quattro 50mm f/2.8

The defining feature of the Sigma dp3 Quattro over its otherwise identical siblings, the dp1 and dp2 Quattro, is its 50mm f/2.8 lens. K Madhavan Pillai discovers what it is capable of.

Over the past few months that I have had the Sigma dp3 Quattro with me, I have turned several of my photographer friends into converts. In previous issues, we have amply reviewed the advantages and constraints of the Quattro dp1 (19mm f/2.8) and dp2 (30mm f/2.8). The body, processing engines, sensor, and other technologies of the dp3 is identical to the others. While all the three cameras are fixed lens compacts, in a departure from the norm, in this issue, we test just the lens of the dp3, to see if it matches up to the stellar optical performances by the dp1 and dp2.

Features
The 50mm f/2.8 of the dp3 provides an equivalent of 75mm on a full-frame sensor. The focal length translates to a medium telephoto lens, making it perfect for portraiture. This also means that there will be significantly improved shallow depthof- field characteristics over the dp1 and dp2. The lens extends quite prominently by roughly 70mm in front of the camera body. The front of the lens does not rotate.

Its optical design consists of 10 elements in 8 groups, with one lens element made of high-refractive index SLD (Special Low Dispersion) glass and one lens element produced by precision glass moulding.

Apertures range from f/2.8 to f/16 and is enabled by a 7-bladed diaphragm. The dp3 features a leaf shutter (the aperture blades double up as the shutter). The aperture used affects the maximum shutterspeed. At f/2.8, it is 1/1250sec. This increases to 1/1600sec at f/4 and remains at 1/2000sec at f/5.6 and beyond. A leaf shutter allows users make creative use of high speed flash sync.

Handling
The barrel of the lens affords a nicely stable left hand hold. Considering the somewhat odd shape of the body, this proves useful at lower shutterspeeds.

The AF locks accurately but is quite slow by today’s standards. The presence of a customisable AF Limit Mode helps. There is a rather useful full-time MF override function available. Both accessing MF and turning on the magnified view on the LCD are simple operations that are enabled through dedicated buttons. The magnified view can be easily switched between 4x and 8x. Confirming focus, however needs to be done visually on the LCD. There is no electronic focus confirmation, let alone features like focus peaking or zebra assist.

Despite the excellent optics, one needs to be cautious with DOF and point of focus. The 50mm lens of the dp3 can be unforgiving. Exposure: 1/80sec at f/8 (ISO 400). Photograph/K Madhavan Pillai

In MF, the LCD shows a distance scale along with an overlaid DOF indicator. While these are useful on the dp1 and dp2, it is inadequate on the dp3. The distances are not detailed enough. Because of this, the DOF indication is too constrained for it to be of any use. The scales need a redesign.

Performance
With 33 million photosites on the sensor, the lens needs to match up. Optically, the 50mm f/2.8 does such a fantastic job of it that there is almost nothing to flaw the lens on. In fact, I would go so far as to say that the lens of the dp3 is perhaps the very best 50mm optics that I have come across.

Fringing is almost non-existent and so is visible distortion. The sharpness is excellent across the aperture range, but the lens shows its best performance between f/5.6 and f/8. Flare is well-controlled. Both foreground and background bokeh characteristics are excellent, with nicely soft edges.

Conclusion
The Sigma dp3 Quattro costs Rs. 60,000/-. I believe Sigma should bundle the lenshood along with the camera, rather than have it as a paid accessory. The Sigma dp3 is not particularly easy to use, nor is it the most feature-packed. However, in terms of image quality at low ISOs and its optics, the dp3 remains unbeatable at its price.