Sigma DP2 Review
The Sigma DP2 is the second compact camera in the world to feature a large APS-C sized sensor, as used in much larger and heavier DSLR models and therefore promising better image quality than other compacts. Principal differences between the DP2 and last year's DP1 model include a longer 41mm lens (the DP1 has a 28mm lens) with a faster aperture of f/2.8, the TRUE II image processing engine which promises to speed up operation, and the Quick Set button which aims to make it easier to change the camera's key settings. In all other respects the DP2 is virtually identical to the DP1, sharing the same 14.06 megapixel Foveon X3 sensor, 2.5 inch LCD screen, full range of creative shooting modes, built-in flash, external hotshoe and RAW format support. Since the release of last year's Sigma DP1, the Micro Four Thirds standard has been launched, with the diminutive Olympus EP-1 as the most comparable model currently available, so Sigma no longer have the market all to themselves. Retailing for £599 / $699, the Sigma DP2 is certainly a serious investment - read our expert review to find out if its worth making.
Ease of Use
As the DP2 and DP1 are virtually identical, a lot of the comments that we made about the DP1 will be repeated here. The Sigma DP2 has a substantial, serious design that is rather box-like but not altogether unattractive. Measuring 113.3(W)×59.5mm(H)×56.1mm(D) and weighing 260grams, the Sigma DP2 is slightly heavier and deeper than the DP1 thanks to the larger 41mm lens. It still fits into a coat pocket or small camera bag, but it's too big and bulky for a trouser or shirt pocket, primarily because of the lens housing which protrudes quite a long out from the front of the camera body. The DP2 becomes even more cumbersome if you add the optional optical viewfinder or lenshood.
Utilising an aluminium alloy body, it's an exceedingly well built camera, certainly up there with the best that the other manufacturers have to offer. The DP2 has an under-stated, all-black appearance, and together with the slightly heavier weight this lends the camera a professional look and feel. The all-metal tripod mount directly inline with the centre of the lens is a giveaway sign that this is intended to be a serious camera (most compacts have a plastic mount squeezed into one of the corners).
The 41mm, F/2.8 lens dominates the front of the camera. Sigma, with its long history of making lenses for other manufacturers' cameras and more recently its own DSLRs, has developed this lens specifically for the DP2. Despite offering a fixed-focal length, the lens extends by approximately 3cms when the camera is turned on, accompanied by a quite audible mechanical noise. The construction of the lens feels rock-solid with no play at all in the metal lens barrel.
Obviously the fixed-focal 41mm lens will immediately put a lot of people off the DP2. With no zoom lens model on the horizon, you're left with a choice of the DP2 or the wider-angle DP1 which has a 28mm lens. 41mm is a good focal length for candid street photography, providing an angle of view similar to what we see with our own eyes, and the combination of the DP2's lens and every photographer's constant companion, their legs, proves to be more versatile than you might first think. The maximum aperture of F/2.8 is also a very welcome upgrade from the DP1, making it even easier to blur the background and importantly more versatile in low-light - the longer, faster lens is one of the few principal differences between the two cameras.
Also on the front of the DP2 is a small dimpled area to the left of the lens (looking from the front) which helps you to keep a firm hold, replicated on the rear below the digital zoom buttons. The 2.5 inch LCD screen is a good compromise given the size of the DP2, being small enough not to overpower the rest of the design, but large enough to easily frame and review your images. It displays 100% of the image and the 230,000 pixel resolution is perfectly adequate, plus there are a couple of options for increasing or decreasing the brightness of the screen if you don't like the default setting.
If you'd prefer using an optical viewfinder to frame your images, Sigma offers the optional VF-21 viewfinder, which fits into the flash hotshoe on top of the camera (you can also use other third-party viewfinders with the DP2). This system does give you a choice, but it comes at the cost of not being able to use the optical viewfinder and an external flashgun at the same time, and also the hefty literal cost of £115 (significantly cheaper if purchased in kit form with the camera). The VF-21 is a very tight fit in the DP2's hotshoe, so there's no danger of it falling off, although it's small enough to misplace when taken off the camera.
As for performance, Sigma's viewfinder solution offers a large, bright view of the scene in front of you. On the other hand, it doesn't provide any feedback to the photographer, other than showing a thick white border which indicates very approximately what part of the scene the DP2 will capture. I found that the recorded image was quite a bit bigger than this border, and also that it disappeared against a bright background, effectively making framing your subject a point and hope experience. Also the only way of knowing that the camera has focused correctly is the small green LED above the LCD screen, which you can just see out of the corner of your right eye when looking through the optical viewfinder.
At the heart of the Sigma DP2 is the APS-C-sized Foveon image sensor. The exact size of the image sensor used in the DP2 camera is 20.7mm x 13.8mm, which is approximately seven to twelve times larger than the 1/1.8inch to 1/2.5 inch image sensors used in other compact digital cameras. Sigma are the only manufacturer to use the Foveon X3 sensor, and as with the SD14 DSLR camera, they quote the resolution as 14 megapixels. Whilst this is technically true, in that there are 14 million pixels on the sensor, it's very difficult to compare it with a conventional Bayer CCD/CMOS sensor. This is because the Foveon solution uses 3 layers of 2652×1768 pixels, stacked on top of each other, with each photodiode capturing all of the RGB data. Sigma and Foveon claim that this results in better looking colour images straight out of the camera when compared to a CCD/CMOS sensor. Whilst this may be true, from the user's point of view the final image is 2652×1768 pixels in size, a little smaller than a 5 megapixel photo, which limits how big you can print or crop the native image without interpolating it in Adobe Photoshop or another application.
Just like a DSLR, the DP2 offers both JPEG and RAW recording formats, one of a handful of compact cameras to do so. There are 3 different JPEG compression levels, and a choice of four sizes including a 16:9 widescreen mode. The RAW files are saved in the Sigma X3F format, which at the time of writing can be processed using the supplied Sigma Photo Pro RAW image developer, Adobe Lightroom 2.4 and Photoshop CS4. Sigma Photo Pro is a simple and straight-forward application that doesn't compare that well with Lightroom or Photoshop in terms of features, but gets the job done and is free of charge.
The new TRUE II image processing engine has thankfully speeded up the DP2's RAW file performance. The DP1 has a real problem with recording RAW files, taking around 7 seconds to store them, during which the camera can't be used, but the DP2 is markedly better, taking around 4 seconds. This still isn't anywhere close to DSLR-like performance though, despite Sigma marketing the DP2 as a real DSLR alternative or backup camera. There's even a 1.5 second lockup when shooting in JPEG mode at full-size, so when you factor in the slow auto-focus system (more on this below), as with the DP1 this makes the DP2 ill-suited to quick moving subjects.
The start-up time from turning the Sigma DP2 on to being ready to take a photo is quite slow at around 3 seconds. In the fastest Continuous mode the camera takes 3 frames per second for an unlimited number of images at the highest JPEG image quality, and commendably in RAW mode too, which is very good for this class of camera. Unfortunately, the DP2 locks up completely for around 10 seconds when shooting a burst of Fine JPEGs and even longer for RAW files, so while you can certainly capture 3 JPEGs or RAW files in a second, the camera is effectively out of action for the next 10-15 seconds.
The Sigma DP2 offers a full range of advanced exposure controls, including aperture-priority, shutter-priority, manual and manual focusing, with Auto and Program AE modes catering for the less experienced. There are no auto-everything or scene modes on this camera, which is a veritable breath of fresh air at a time when most manufacturers are stuffing their cameras full of clever technologies that take control away from the user. The aperture or shutter speed are set by using the Zoom In / Zoom Out buttons, with the left and right buttons on the navigation pad setting the aperture in the Manual shooting mode and exposure compensation in the other modes. Not the most elegant of systems, but it gets the job done.
The DP2 has three metering modes, Evaluative Metering, Center Weighted Average Metering and Spot Metering. I found that the DP2 got exposures right 95% of the time when using the Evaluative Metering mode, with Spot Metering useful for the remaining 5%. Exposure compensation can be set in 1/3 stop increments from +3.0 to -3.0 stops and a simple auto bracketing function is also available.
Focusing is one of the weaker points of the DP2. There are 9 focusing points to choose from, but you can only select one at a time, with no multi-AF point system that virtually all other cameras have. There's now a dedicated button (down on the navigation pad) for choosing the focus point, but it's still easier and quicker to set the focus to the middle point, then focus by half-pressing the shutter button and recompose the frame for off-centre subjects.
The DP2 offers a rather confusing choice of focusing options, with two autofocus modes available. The normal mode has a focusing distance from 50cm to infinity, but it's also possible to shorten the minimum focusing distance to 28cm using the second mode. I didn't notice any speed differences between the two modes, so permanently set the DP2 to the 28cm short mode. Finally, the DP2's autofocus system isn't what you'd call snappy, especially in low-light. It always locks onto the subject eventually, but there's a noticeable delay that doesn't make this camera particularly good for action photography. Note that the DP2 doesn't have a built-in focus assist lamp.
Manual Focus is also available, which obviously avoids the auto-focus lag and speeds up the camera. The DP2 has a dedicated manual focus dial located above the digital zoom buttons on the rear of the camera, with markings indicating 0.28m, 0.35m, 0.4m, 05m, 06m, 1m, 2m, 5m and infinity. The dial rotates freely with no lock at the various distances, so it's easy to set the distance, put the camera in your pocket, and then find that the dial has moved to another position. It is possible to magnify the LCD display to check the focusing by pressing the Display button, although this doesn't provide enough magnification or clarity to ensure precise focus.
The Sigma DP2 offers two flash solutions, the built-in pop-flash unit which is positioned above and to the right of the lens, and an optional flashgun which fits in the external hotshoe directly above the lens. The pop-up flash is opened via a switch on the back and isn't very powerful, with a guide number of 6 and a range of 28cm-3m at ISO 200. On the upside it does feature flash exposure compensation in 1/3 stops increments for more precise control. Sigma suggest that you use the optional EF-140 DG external flashgun with the DP-2, but again there are compatible third-party alternatives available.
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A dedicated lens hood is the final optional accessory for the DP2. This blocks out extraneous light and helps avoid flare, useful given the wide-angle nature of the lens, although unfortunately we didn't have one to test. The lens hood also includes a hood adapter which is designed to accept a 46mm lens filter, so you can add things like a polarizer, UV or close-up macro filter. The closest distance that you can focus on a subject is 28cms away from the camera when it's set to Full Focus mode, so you'll need to buy the lens hood and then fit a third-party close-up macro filter if you want to get really close to your subject.
The main menu system on the Sigma DP1, accessed by pressing the Menu button above the navigation pad, is rather rudimentary but simple to use. There is a single long list of 21 options, such as image size, sharpness, metering mode and continuous mode. Due to the large LCD screen and restricting the number of on-screen choices to 7, the various options and icons are quite clear and legible, and each option uses a combination of text and helpful small icon. There is one small annoyance - whenever you press the OK button to access a menu option, you then have to press the Display button to effectively "close" that option and be able to move onto the next one via the arrow keys.
A new addition to the DP2 is the Quick Set menu, borrowed directly from the Sigma SD14 DSLR. Accessed via the new QS button above the Menu button, this provides quicker access to eight key features - ISO, Metering, Whie Balanace, Flash, Image Size, Burst Mode, Colour Mode and Image Quality. There are four options on each of the two QS screens represented by icons, with the QS button toggling between the two. The navigation pad keys are then used to select the various options for each feature. It sounds complicated on paper, but quickly becomes second nature to use, and is a very welcome addition to the DP2.
If you have never used a digital camera before, or you're upgrading from a more basic model, reading the easy-to-read but rather brief 100+ page manual before you start is a must. Thankfully Sigma have chosen to supply it in printed format, rather than as a PDF on a CD, so you can also carry it with you for easy reference in the field.
Once you have captured a photo, the Sigma DP2 has a rather limited range of options when it comes to playing, reviewing and managing your images. You can instantly scroll through the images that you have taken, view thumbnails (9 onscreen at once), zoom in and out up to 10x magnification, view slideshows with various configurable options, set the print order, record a soundclip, lock, mark, and rotate an image. The Display button toggles detailed settings information about each picture on and off, such as the ISO rating and aperture / shutter speed, and there is a small RGB histogram available during playback (but unfortunately not when taking a picture). You can also turn on the useful Exposure Warning shows a flashing red area for any overexposed parts of a recorded image. When taking a photo, pressing the Display button toggles between the detailed information, the small histogram, no information and turning the LCD screen off.
In summary the Sigma DP2 is much like the DP1- a no-frills camera that some people won't see the point of, but which others will be delighted by. The faster image processing engine and Quick Set menu substantially improve the camera's handling, although it's still quite a slow camera and hampered by the same unresponsive auto-focus system as the DP1.