Photography News issue 23

Camera test 42

Photography News Issue 23 absolutephoto.com

Full test Sigma dp0Quattro The unique design of the Foveon sensor means every photodiode can detect all colours of light with the promise of accurate colours. Does the Foveon X3 Quattro in the dp0 deliver?

Specs

Price £899.99, £999.99 kit comprising dp0 & LVF-01 LCD viewfinder Sensor Foveon X3 Direct Image CMOS sensor, 29 megapixels effective approx Sensor format 23.5x15.7mm, 5424x3616 pixels maximum. 14-bit lossless Raw and three JPEG levels, fine, normal and basic. Six aspect ratios available ISO range 100-6400 in 0.3EV steps Shutter range 30secs to 1/2000sec Drivemodes Single, continuous, self-timer (2 or 10secs) intervalometer Metering system Evaluative, spot, centre-weighted average Exposuremodes PASM Exposure compensation +/-3 in 0.3EV steps. AEB 3 shots up to +/-3EV in 0.3EV steps Monitor 3in LCD TFT with 920k dots Focusing Contrast-detection type AF with 9 points select mode. Free move mode. Face-detection mode option. Manual focus possible Colourmodes 11 styles including Landscape, Cinema, Sunset Red, Forest Green, Monochrome Connectivity USB, cable release Storagemedia 1xSD/SDHC/SDXC Power Li-ion battery pack BP-51, battery life 200 shots approx Dimensions (WxHxD) 161x67x126mm Weight 554g with battery, with battery and LVF-01 818g Contact sigma-imaging-uk.com

The dp0 is now available as a kit with the LVF-01 LCD viewfinder for £999.99. This finder fits the other Quattro compacts too. The finder mount screws to the base of the camera and the finder then slides into position. It’s an optical finder that magnifies the LCD by two and a half times so enables critical focusing checking and accurate composition regardless of the external light. The camera’s styling is eye- catchingly different, and very Marmite – you either love or hate it. The wide body has handling benefits and there’s plenty to grab hold of. Also, although Sigma calls it a ‘compact’, it is nothing of the sort with a seven-inch wide body and a lens that protrudes four inches from the body. Add the LVF-01 and it protrudes from the back as much as the lens does from the front. Lens front to eyepiece distance is now similar to a 70-200mm f/2.8. Although bulky, for convenience the finder can be left in place even when the camera is being carried. With or without the finder, the dp0 is a conspicuous piece of kit, although its size and shape does give a secure shooting platform. With the left hand supporting the lens and the camera up to the eye it is just like using a DSLR so that adds stability straight away. The lens itself has a thin serrated barrel to assist manual focusing but

actually most of the barrel rotates so no problem here and it is worth noting that the lens front does not rotate during focusing which filter users will appreciate. At the dp0’s heart is the Foveon X3 Quattro direct image sensor, a sensor with three photodiode sensor layers – the top layer captures brightness and colour information, the bottom two layers capture colour data only. Each diode captures all light wavelengths vertically whereas conventional sensors have diodes arranged in one horizontal layer where each sensor can only capture red, blue or green light. Foveon’s sensor design means no low-pass filter is needed either. The sensor is 5424x3616 pixels, which gives a 19.6-megapixel resolution, but the Foveon sensor captures twice as much information as a conventional sensor so the dp0’s effective resolution is 39 megapixels. A Raw file is around 55MB on card and a JPEG around 12MB. Full- size JPEGs and processed Raws can give a print size, without any interpolation, of 18x12in at 300ppi. The dp0 delivers excellent image quality at its lower ISO settings, but venture into the ISO800andbeyond range and the files are not suited for critical use. Colour reproduction is excellent at ISO 400 and slower. Although this is not a sensor technology comparison, I did shoot the same

Words by Will Cheung

Sigma made its reputation as an independent lens maker producing high-quality lenses for the leading SLR brands. Cameras came a bit later and when Sigma went digital with the SD9 in 2002 it took a unique approach. Rather than use sensors with a mosaic pattern where red, green and blue light wavelengths are captured by separate red, green and blue pixels, Sigma used the Foveon X3 sensor where all light wavelengths are captured at every pixel site. The theory makes perfect sense and better colour resolution has been the claim right from the beginning. And that’s still the case now, although naturally the Foveon sensor has moved on and the latest cameras use the Foveon X3 Quattro sensor, of which more later. The dp0 Quattro belongs to a family of large sensor compact cameras each fundamentally identical with the exception of the fixed lens. The dp1 has a 19mm f/2.8 lens (equivalent to a 28mm lens on a 35mm format camera), the dp2 has a 30mm f/2.8 (45mm equivalent), the dp3 has a 50mm f/2.8 (75mm equivalent) and the dp0 tried here has a 14mm (equivalent to a 21mm). The guide price for all these cameras is £899, with street prices around the £799 mark.

The dp0’s styling is eye-catchingly different, and very Marmite – you either love it or you hate it