From the Manufacturer
Implementing a large sensor presented all sorts of problems: the cost of the sensor, the difficulty of designing the lens, the high processing capacity required for the image-processing engine, enlarging the circuit board, increasing the memory capacity, and so on. Until these problems could be overcome, it was generally accepted that DSLRs used large sensors, and compacts used small ones. Eventually, these problems were effectively solved, allowing sensors to be made smaller. However, this involved a trade-off: reduced image quality.
From then on, amateur photographers dreamed of a compact digital camera with an SLR-sized image sensor. A camera small and light enough to carry around everywhere, yet offering the technology for serious photography. Those dreams have come true with Sigma’s DP series. The DP Series: A New Lineage
The DP2's integral standard lens is brand-new and purpose-designed, with a focal length equivalent to 41mm in a 35mm camera. We wanted to allow photographic effects beyond the scope of the focal length of the wide-angle lens of the DP1, which is equivalent to 28mm in a 35mm camera. So we gave the DP2 a standard-range focal length more suitable for snapshots and portraits. The Camera That Turns Ordinary into Awesome
The DP1's wide-angle lens is good with perspective, geared towards dynamic shots of scenery, buildings, celebrations. The standard lens built into the DP2, on the other hand, has a narrower field angle, giving a stronger effect, making the subject stand out. In other words, we've given it the ability to create the photo that you, and only you, can see in your mind's eye. Naturally, this is great for portraits. And for capturing the elusive beauty of ordinary, everyday subjects, this standard lens is ideal.
Its focal length is longer than the DP1's lens. So, at low F-numbers (larger apertures), you can create amazing pictures by deliberately blurring the background. This makes the subject stand out sharply, in a compelling, almost mystical way. In this sense, you could say the DP2 turns ordinary into awesome. Sigma DP2 Highlights & Features Full Scale Sensor Startlingly evocative image quality
At 20.7 x 13.8mm, the DP2's 14-megapixel image sensor is SLR-sized. This is about 12 times larger than the 1- to 2.5-inch sensor, and 7 times larger than a 1- to 1.8-inch sensor used in a conventional digital compact. This generous size takes the DP2's image quality to a different dimension.
Picture this. Light traveling through a small lens is captured by a small sensor and turned into an image. Light travelling through a large lens is captured by a large sensor and turned into an image. What’s the difference between these two images? Essentially, it's a difference in quality. In the case of the small image sensor, the image is magnified by a high ratio when it's printed or displayed on a computer screen. This makes it tricky to reproduce the dynamism and 3-D feel of the subject. The DP2 does just that by using a large integral image sensor. The natural background blur you get with an SLR
The small size of the image sensor used in a conventional compact digital camera explains why it captures rather flat, unmodulated images. If the image sensor is small, the focal length of the lens is short. The shorter the focal length of the lens, the greater the depth of field - in other words, the greater the range of distances over which the lens can focus.
The prosaic quality of the images captured by an ordinary compact digital camera is caused by the depth of field characteristic of a small image sensor: the lens focuses evenly on everything between the subject and the background, eliminating any cadence within the image. The DP2, however, has an SLR-sized image sensor, so its standard lens is equivalent to 41mm in a 35mm camera, and with an F-number of 2.8, it has a large aperture as well. This means you can utilize the kind of cool natural background-blur effects you would normally expect of an SLR. Direct Image Sensor
The DP2's Foveon X3 direct image sensor utilizes the special properties of silicon, which is penetrated to different depths by different wavelengths of light, to successfully achieve full-color capture for the first time ever in a single-pixel site configuration. No color filter is required. Like modern color film cameras, it uses a method that captures all the colors vertically.
Because it does not need color interpolation or a low-pass filter, the Foveon X3 produces images that are sharp right from the start. Therefore, sharpness processing in the latter stages of the image processing - creating edges and emphasizing contours - can be reduced to a minimum. This is why reviewers have evaluated the images captured by the Foveon X3 as having a truly nuanced, sharp feel and praised them as very natural and demonstrating superior image quality. Integral Lens The DP2 Features a Standard Integral Lens
A lens with a focal length of 40mm to 60mm on a 35mm film camera is known as a "standard lens" because it delivers natural perspective, close to what the human eye perceives. The usual definition of a standard lens is one that has a focal length close to the diagonal length of the image format. The focal length of the DP2's lens is 24.2mm, and the diagonal length of the image sensor is 24.86mm. So, the lens used in the DP2 really does deserve to be called a standard lens.
In the past, standard lenses have traditionally been of either the Tessar or the Gauss type. The Gauss type is basically used for larger apertures with high performance. Its disadvantages include susceptibility to saggital coma flare when used with a point light source, and a tendency for the light volume to decrease towards the periphery. The Tessar type, on the other hand, has a simple structure, making it easy to miniaturize. However, its drawback is that it tends not to deliver high performance at larger apertures. Adapting SLR Lens Technology for Our Own Purposes
Sigma believes that a photo is only as good as the lens it was taken with. So we decided that the kind of quality we wanted for the DP2 would not be attainable using the traditional techniques used to design standard lenses. We rethought the design from the development stage, and set out in pursuit of the highest possible lens performance. We took the bold step of using a retrofocus lens of the type mainly used as wide-angle lenses for SLRs.
Besides having the excellent telecentricity vital in lenses for digital cameras, this retrofocus lens has many other advantages: for example, this format makes it easy to suppress field curvature and astigmatism, and to ensure that the light volume stays the same right to the periphery. However the lens does need to be longer. Therefore, in order to minimize the total length of the lens while still attaining ideal image quality, we used two groups of lens elements: the group at the front have a high refractive index, and the group at the rear are aspherical glass-mold lenses. This way, we successfully developed a standard lens with a relatively modest overall length, but very high optical performance. Creating sharp, clear images
As well as employing a rear-focus system, we used aspherical glass-mold lenses, enabling aberration variation to be minimized. And the elements that make up the DP2 lens have been treated with a super-multilayer coating that succeeds in keeping ghosting and flare to a minimum.
That's not all. Some of the DP2 lens elements are hyperchromatic, which enables chromatic aberrations to be corrected to a large extent, without impacting other aberrations. This means that even with a wide-open aperture, the images produced have minimal color flare, and are nice and sharp and crisp, right to the edge. The Foveon X3, which delivers amazing color resolution, also makes a big contribution to the very high level of "emotional image quality" delivered. A super high-performance lens that's flat as a pancake right to the edge
In order to maintain high resolution and contrast from the center of the screen right to the edge, and to allow scope for those cool background-blur effects, we aimed for the kind of MTF and all-round lens performance only available with single-index lenses. We are confident that the DP2's lens, improved time and time again in the interests of delivering the best possible finished image, encapsulates Sigma's expertise as a leading manufacturer of lenses. The impact of the eye-popping image quality delivered by the DP2's lens is something you really need to see for yourself. Imaging Capability Proprietary X3F format for outstanding texture and color
In fact, shooting in X3F format has some advantages. In a digital camera, the image signal captured in RGB is recorded by being converted into what is known as YCbCr color space. The Y stands for brightness, and the CbCr stands for color difference. In an ordinary digital camera, a file format known as YCbCr 4:2:2 is used, where the color signal is set to half the brightness signal. This format was developed in order to send color information efficiently on the limited bandwidth available back when color television was first developed. Designed on the principle that the human eye is less sensitive to color data than to brightness data, this historical format has survived intact to this day, and is still used as the mainstream format in digital cameras.
However, now that digital camera performance has improved so dramatically, people are using their photos in different ways, displaying enlargements on their computer screens, and large photo prints are mainstream. Today's output conditions are getting better and better. The old YCbCr 4:2:2 format was designed for efficient signal transmission, and not for high-quality output. To our way of thinking, this format no longer adequate to meet the needs of all photographers. X3F images preserving the balance of the natural data
The JPEG files from the DP2 are output in YCbCr 4:2:2 in compliance with the Exchangeable image file format (Exif) specification, which is the standard specification for file formats. But in the direct image sensor, each pixel location captures the full complement of RGB color data, so in X3F files, which is the RAW data format, brightness data and color data can be kept in a 1:1 ratio without relying on interpolation. When this image is processed in Sigma Photo Pro, even if it is saved as a JPEG, if the JPEG quality-setting selected is 7 to 12, it will be saved as YCbCr 4:4:4. The DP2's image quality, with its amazing vividness and texture, is really due to the X3F image data, which preserves the balance of the natural data. For the best photos with the best image quality, we definitely recommend shooting in X3F mode. JPEG mode: photos finished the Sigma way
JPEG images captured by the DP2 are photos finished in what Sigma considers the most appropriate way. If you find that the photos you take in JPEG mode look the way you intended, then by all means enjoy the ease and convenience of the JPEG setting. Your JPEG images are ready to print - just plug the camera into your printer - and the image data files are ready to share with your friends and family. If you want email-friendly image files that can be transferred straight from your camera, JPEG mode wins hands-down on convenience.
However, when you create a JPEG file, the data is subjected to irreversible compression, which leaves very little scope for image-correction afterwards. And here's the rub: if you only shoot JPEG mode, you may find it very difficult to reproduce the photo you saw in your mind's eye, which is your own personal sensory experience. If you've ever used a conventional compact digital camera that only has JPEG mode, you'll know how unsatisfying the results can be. Unfortunately, it can be extremely difficult to fully express your artistic vision using only JPEG images, which are created using the camera’s automatic settings.
True II image processing engine
The DP1 offers a specially-designed image-processing engine called the "TRUE". For the DP2, we developed this key technology further, creating the "TRUEII". Applying our exhaustive knowledge of the image-creation mechanism of the direct image sensor, we used a proprietary algorithm to do full justice to its uniquely sophisticated 3-D rendering power, successfully optimizing both the image-processing time and the in-camera image processing itself.
Having focused our efforts on optimizing and recording the pure, rich signal captured by the sensor, we were determined that the DP2 would be the only camera fully able to deliver the optimal image quality we had pursued throughout our development of SLRs. The rich optical signal captured by the groundbreaking direct image sensor needed to be translated into an information-rich image. We entrusted that crucial task to our new, improved "TRUE II". Enhanced image processing quality and speed
Leveraging the strengths of the direct image sensor, TRUE II does full justice to its uniquely sophisticated 3D rendering power, optimizing both in-camera image processing quality and speed. Also enhancing color reproduction and dynamic range, TRUE II, significantly contributing to the quality of the images produced within the camera. Further, noise that can tend to occur at higher sensitivities is suppressed by a new proprietary algorithm, with resolution maintained at the highest possible level.
And automatic exposure, focus and white balance functionality are strengthened, enhancing the camera's overall performance. Sigma Photo Pro Photo-finishing software designed to make you and your works shine (Not included)
The DP2 has an X3F mode (RAW file format) in which all the image data captured by the sensor can be recorded without any significant deterioration in camera performance. If you want to do your own hands-on photo-finishing, then for best results, we recommend Sigma Photo Pro, the image-processing software designed exclusively for these X3F files.You may think that "RAW data processing" sounds like something intimidatingly technical, requiring high levels of knowledge and skill.
If so, just try Sigma Photo Pro for yourself, and you'll soon find out how easy it really can be. Sigma Photo Pro focuses on only those functions you really need for artistic photo-finishing. Its interface is one of the most user-friendly and intuitive of the many RAW data-processing software packages on the market, so even if you're a beginner, you'll find it simple to turn your images into finished photos. Images can be customized using just seven parameters -- exposure, contrast, shadows, highlights, color saturation, sharpness and X3 Fill Light -- all provided in the Adjustment Controls Palette, plus the Color Wheel for adjusting the colors. Simply adjust these parameters and watch the image change in real time. That's all it takes to recreate the ideal photo you had in your mind's eye as you pressed the shutter. Design Policy A truly intuitive user interface
The business of taking photos boils down to the skill of the photographer. The photograph is the canvas for the photographer's individual self-expression. Sigma creates equipment for delving into the essence of photography. Sigma's design policy is to empower the photographer to concentrate on the core task: taking pictures. Our top priority is to deliver the functionality and reliability this requires. That's way in adding extra features, we've been generous to a fault.
The rather simple user interface we gave the DP1 has been refined for the DP2, making it even easier to shoot pictures just the way you want. Because it's a lightweight compact, we've focused on making it a more complete photographic tool that you can carry around with you every day. A stylish new outlet for your inner artist
With its intuitive controls, and its increased portability and toughness, the DP2 is made to be taken with you anytime, wherever you go. Simple yet distinctive, its compact body will draw admiring glances. Packed into a neatly pocket-sized package, it has a capacity to deliver uncannily high image quality that is bound to amaze. Doing away with the old DSLR-versus-compact distinction that cramped photographers' style more than they ever knew, the DP2 offers more artistic freedom, and new horizons in photographic expression, making the finest in photography far more accessible than ever before.