Introduction

Ease of Use

At the heart of the Sigma DP1 Quattro is a brand new APS-C sized Foveon image sensor. The exact size of the image sensor used in the DP1 Quattro camera is 23.5x15.7mm, slightly larger than the DP1 Merrill's sensor. Sigma are still the only manufacturer to use the Foveon X3 sensor, quoting the resolution of the DP Quattro as 39 megapixels.

The Foveon solution uses 3 layers of stacked on top of each other, with each photodiode capturing all of the RGB data. The Quattro sensor differs from the prvious generation by allocating 20 megapixels to the top layer which records both blue colour and luminance information, and only 4.9 megapixels to the other two layers which record green and then red colour information respectively. Sigma say that this important change offers an an increase in resolution compared to the previous Foveon sensor, along with faster processing times and less noise, at least in the red and green channels.

Sigma and Foveon also continue to claim that the 3-layer approach 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 5424x3616 pixels in size, which limits how big you can print or crop the native image without interpolating it in Adobe Photoshop or another application.

Front of the Sigma DP1 Quattro

The Sigma DP1 Quattro has a very unusual design that's quite unlike any camera that we've seen before. Measuring 161.4mm(W) x 67mm(H) x 87.1mm(D) and weighing 425grams, it's substantially wider and heavier than the DP1 Merrill, no longer fitting into a coat pocket. It's much too wide and bulky for that, primarily because of the lens housing which protrudes about 4cms out from the front of the camera body, not to mention the angular hand-grip. The DP1 Quattro becomes even more cumbersome if you add the optional VF-41 optical viewfinder and/or the LH4-01 lenshood.

Utilising an aluminium alloy body, the Sigma DP1 Quattro is an exceedingly well built camera, certainly up there with the best that the other manufacturers have to offer. The DP1 Quattro has an under-stated, all-black appearance with a subtly textured surface, and together with the 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 19mm, F/2.8 lens dominates the front of the camera. Offering a fixed-focal length of 28mm in 35mm camera terms, the lens doesn't extend when the camera is turned on. The construction of the lens feels rock-solid with no play at all in the metal lens barrel. The DP1 Quattro has a tactile manual focus ring, which makes it much easier to operate the camera if you prefer that way of focusing. Sadly it doesn't over-ride the auto-focus mode though, which would have been a nice feature, although the manual focus assist complete with on-screen magnification is a nice touch.

Obviously the fixed-focal 19mm lens, equivalent to 28mm on a 35mm camera, will immediately put a lot of people off the DP1 Quattro. If you want a different focal length, then the DP2 Quattro has an equivalent 45mm lens, or the DP3 Quattro has a 75mm lens. 28mm is a good focal length for both candid street and more formal landscape photography, and the combination of the DP1 Merrill'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 and the large APS-C sensor makes it easy to blur the background and importantly makes the camera more versatile in low-light.

Rear of the Sigma DP1 Quattro

The DP1 Quattro has a subtly sloped handgrip with a small leatherette area which helps you to keep a firmer hold, although we'd have liked to see a much bigger area covered by this material. Unusually the DP1 Quattro grip is bigger at the rear of the camera than the front, an arrangement that we could never, ahem, quite get to grips with properly, especially as the Focus button and Control Pad are located where your right thumb naturally wants to sit, while the metal lug for the shoulder strap digs into your fingers. The DP1 Quattro's handgrip is definitely distinctive, but it has a rather detrimental effect on the camera's handling.

The 3 inch LCD screen on the rear displays 100% of the image and the 920,000 pixel resolution is good, plus there are a couple of options for increasing or decreasing the brightness of the screen if you don't like the default setting. Rather strangely the DP1 Quattro's looks bigger than it really is at first glance, until you realise that the 3-inch LCD is positioned within a much bigger glass panel, with a tiny activity LED on one side and Play button on the other.

If you'd prefer using an optical viewfinder to frame your images, Sigma offers the optional VF-41 viewfinder, which fits into the flash hotshoe on top of the camera (you can also use other third-party viewfinders with the DP1 Quattro). 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 £180.

Just like a DSLR, the DP1 Quattro offers both JPEG and RAW recording formats. There are 3 different JPEG compression levels (Fine, Normal, Basic), three resolution settings (Super-high, High Low) and a choice of five crop modes (21:9, 16:9, 3:2, 4:3 and 1:1). The RAW files are saved in the Sigma X3F format, which currently can only be processed using the free to download Sigma Photo Pro RAW 6 image developer (not supplied in the box). Sigma Photo Pro is a simple, straight-forward but rather slow 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. We really wish that Sigma would support the Adobe DNG format so that we could use our favourite processing software from day one. Note that if you shoot in the RAW mode, you can't also choose the Super-High resolution in-camera, although you can develop the RAW file into a Super-High file using Sigma Photo Pro in post-processing.

Side of the Sigma DP1 Quattro

The start-up time from turning the Sigma DP1 Quattro on to being ready to take a photo is OK at around 1.5 seconds. It takes around 10 seconds to store RAW files, although thankfully you can take another shot almost straight-away, which addresses one of our main criticisms of the previous Merrill generation. The DP1 Quattro even has a respectable burst mode of 3.5fps should you feel the need, although it can only capture 7 RAW/High files before the camera locks-up completely for a few seconds. Still, it's a big improvement on the DP1 Quattro's predecessors.

The Sigma DP1 Quattro offers a full range of advanced exposure controls via the Mode button on top of the camera, including aperture-priority, shutter-priority, manual and manual focusing, with Auto and Program AE modes catering for the less experienced and three Custom modes so that you can save and recall your preferred settings. 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 forefinger-operated control dial on top of the camera which encircles the shutter button, with a new smaller control dial just behind the first one setting the aperture in the Manual shooting mode and exposure compensation in the other modes.

The DP1 Quattro has three metering modes, Evaluative Metering, Center Weighted Average Metering and Spot Metering. 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.

Auto-focusing remains one of the weaker points of the DP1 Quattro. There are 9 focusing points to choose from and three point sizes, but you can only select one at a time, with no multi-AF point system that virtually all other cameras have. There's 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 DP1 Quattro's autofocus system still isn't exactly what you'd call snappy, especially in low-light. It usually locks onto the subject eventually, but there's a noticeable 0.5 second delay that doesn't make this camera particularly good for action photography. Note that the DP1 Quattro does now have a built-in focus assist lamp, unusually located on the lens barrel.

Top of the Sigma DP1 Quattro

Manual Focus is also available, which obviously avoids the auto-focus lag and speeds up the camera. The DP1 Quattro has a dedicated manual focus ring on the lens barrel. It is possible to magnify the LCD display by 8x to check the focusing by pressing the OK button, although this doesn't provide enough magnification or clarity to ensure precise focus. The Sigma DP1 Quattro doesn't have a built-in pop-flash unit, just an optional flashgun which fits in the external hotshoe directly above the lens. Sigma suggest that you use the optional EF-140S external flashgun with the DP1 Quattro.

A dedicated lens hood is the final optional accessory for the DP1 Quattro. 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 20cms 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.

It's fair to say that movies aren't exactly the Sigma DP1 Quattro's strong point, in that Sigma have now completely removed video recording. The battery life has thankfully been improved, with a CIPA quoted life of 200 shots - we managed 180 images before needing to recharge. Sigma have also commendably decided to continue supplying two batteries in the box, despite the much better battery life (the DP1 Merrill could only manage around 80 shots per charge).

The main menu system on the Sigma DP1, accessed by pressing the Menu button above the navigation pad, is still rather rudimentary but simple to use. There are three tabs along the top, Camera, Play and Settings, subdivided into 5, 2 and 4 screens of options respectively. Due to the large LCD screen and restricting the number of on-screen choices to 5, the various options and icons are quite clear and legible, and each option uses a combination of text and helpful small icon.

The Sigma DP1 Quattro In-hand

The more intuitive Quick Set menu is accessed via the QS button above the Menu button, as the name suggests providing quicker access to eight key features - ISO, Metering, Burst Mode, White Balance,, Image Size, Image Resolution, Crop Mode and Colour Mode. The navigation pad keys and rear control dial are then used to select the various options for each feature.

Once you have captured a photo, the Sigma DP1 Quattro 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 histogram available during playback and also when taking a picture. You can also turn on the useful Exposure Warning which 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 with an electronic level, a status screen with no live preview, and turning the LCD screen off.

In summary the Sigma DP1 Quattro is a no-frills, niche camera that most people won't see the point of, but which a minority will be delighted by. Despite improvements to the processing speed, it's still a camera that is best suited to slow-moving or stationary subjects, while you'll either love or hate the unconventional design.

Image Quality

All of the sample images in this review were taken using the Fine / High JPEG setting, which gives an average image size of around 25Mb.

The Sigma DP1 Quattro's image quality is outstanding when shooting in the RAW format, with great results from ISO 100-1600. Curiously the quality drops off noticeably when shooting JPEGs, with only ISO 100-400 worth using thanks to a lot of noise and colour desaturaion at the higher ISOs, so our advice would be to always use the DP1 Quattro's RAW mode if possible (despite the so-so Sigma Photo pro software and the huge file sizes).

The Sigma DP1 Quattro dealt with chromatic aberrations so well that we struggled to find a single example from the hundreds of frames that we shot. The images were just a little soft straight out of the camera at the default sharpening setting, but you can increase the level in-camera, or use Adobe Photoshop later. The night photograph was very good, with the maximum shutter speed of 30 seconds allowing you to capture enough light for the majority of after-dark situations. Macro performance was the only slight fly in the ointment, only allowing you to focus as close as 20cms away from the subject.

Noise

There are 7 ISO settings available on the Sigma DP1 Quattro for both JPEGs and RAW files. Here are some 100% crops which show the noise levels for each ISO setting, with JPEG on the left and RAW on the right:

JPEG	RAW
ISO 100 (100% Crop)	ISO 100 (100% Crop)
ISO 200 (100% Crop)	ISO 200 (100% Crop)
ISO 400 (100% Crop)	ISO 400 (100% Crop)
ISO 800 (100% Crop)	ISO 800 (100% Crop)
ISO 1600 (100% Crop)	ISO 1600 (100% Crop)
ISO 3200 (100% Crop)	ISO 3200 (100% Crop)
ISO 6400 (100% Crop)	ISO 6400 (100% Crop)

Sharpening

Here are two 100% crops which have been Saved as Web - Quality 50 in Photoshop. The right-hand image has had some sharpening applied in Photoshop. The images are just a little soft at the default sharpening setting of 0. You can change the in-camera sharpening level to one of the 10 preset preset levels (0.2 increments on a scale of +1 to -1) if you don't like the default look.

Original (100% Crop)	Sharpened (100% Crop)

File Quality

The Sigma DP1 Quattro has 3 different JPEG image quality settings available, with Fine being the highest quality option. Here are some 100% crops which show the quality of the various options, with the file size shown in brackets.

Fine (13.8Mb) (100% Crop)	Normal (6.62Mb) (100% Crop)
Basic (4.01Mb) (100% Crop)	RAW (53.4Mb) (100% Crop)

Chromatic Aberrations

The Sigma DP1 Quattro handled chromatic aberrations so well during the review that we struggled to find a single example to show you. You won't notice any chromatic aberrations in almost all photos from the DP1 Quattro.

Chromatic Aberrations 1 (100% Crop)

Macro

The Sigma DP1 Quattro doesn't offer a dedicated Macro setting. The closest distance that you can focus on a subject is 20cms away from the camera when it's set to Full Focus mode. The first image shows how close you can get to the subject (in this case a compact flash card). The second image is a 100% crop.

Macro	Macro (100% Crop)

Night

The Sigma DP1 Quattro's maximum shutter speed is 30 seconds, which is good news if you're seriously interested in night photography. The shot below was taken using a shutter speed of 30 seconds at ISO 100.

Night	Night (100% Crop)

Color Modes

The Sigma DP1 Quattro offers 11 different color modes.

Standard	Vivid
Neutral	Portrait
Landscape	Cinema
Sunset Red	Forest Green
FOV Classic Blue	FOV Classic Yellow
Monochrome

Sample Images

This is a selection of sample images from the Sigma DP1 Quattro camera, which were all taken using the Fine / High JPEG setting setting. The thumbnails below link to the full-sized versions, which have not been altered in any way.

Sample RAW Images

The Sigma DP1 Quattro enables users to capture RAW and JPEG format files. We've provided some Sigma RAW (X3F) samples for you to download (thumbnail images shown below are not 100% representative).

Product Images

Front of the Sigma DP1 Quattro

Front of the Sigma DP1 Quattro / Turned On

Side of the Sigma DP1 Quattro

Side of the Sigma DP1 Quattro

Rear of the Sigma DP1 Quattro

Rear of the Sigma DP1 Quattro / Image Displayed

Rear of the Sigma DP1 Quattro / Turned On

Rear of the Sigma DP1 Quattro / Main Menu

Rear of the Sigma DP1 Quattro / Mode Menu

Rear of the Sigma DP1 Quattro / Quick Menu

Top of the Sigma DP1 Quattro

Bottom of the Sigma DP1 Quattro

Side of the Sigma DP1 Quattro

Side of the Sigma DP1 Quattro

Front of the Sigma DP1 Quattro

Front of the Sigma DP1 Quattro

Memory Card Slot

Battery Compartment

Conclusion

Sigma continue to take a solitary path with the new DP1 Quattro, remaining the only camera manufacturer to use the Foveon sensor technology. Despite some improvements to the processing speed, the Sigma DP1 Quattro is still a rather slow camera that's really only suited to static or slow-moving subjects, while the rather radical new design favours image quality over usability (apparently moving the memory card and battery away from the sensor helps to improve the former) - suffice to say, we didn't really get on with the much bigger DP1 Quattro with its awkward grip.

Despite those misgivings, though, the images that the DP1 Quattro produces are simply outstanding, by far the best images that we've seen from a mere compact camera and even rivaling a high-end DSLR with an equivalent and expensive prime lens. The DP1 Quattro may take a lot of getting used to, but it certainly takes great pictures.

The Foveon X3 Quattro sensor, whether you believe it to have the 39 megapixels that Sigma claim or or the native 20 megapixels of the top blue/luminance layer, and the prime 19mm lens deliver stunningly sharp, high-resolution images that are better even than the previous DP1 Merrill. Chromatic aberrations are once again non-existent on the DP1 Quattro, testament to the excellent prime lens, which is also the reason for the almost complete lack of pincushion or barrel distortion, and the fast maximum aperture of f/2.8 is very welcome.

So once again, it's a case of image quality to the rescue for the DP1 Quattro - the 3-layer Foveon technology really does deliver a different look to cameras with Bayer sensors, a look that we like a lot. Only you can decide if this is enough to persuade you to splash out quite a lot of cash for an undeniably quirky, pared-back camera with a fixed focal-length lens that is really only suited to a slower, more considered approach. If that sounds like your cup of tea, then you won't be disappointed by the breath-taking images that the Sigma DP1 Quattro is capable of...

Ratings (out of 5)
Design	3
Features	3.5
Ease-of-use	3
Image quality	5
Value for money	3.5

Main Rivals

Listed below are some of the rivals of the Sigma DP1 Quattro.

Specifications

Your Comments