Testing Out The Sigma DP2 Merrill camera
A few weeks ago, a friend of mine who is a commercial pilot, and studying engineering whilst doing photography as a hobby on the side, told me about this camera that sounded too good to be true. That it was a digital camera that was able to capture colours like film does.
He explains thus:
In order to understand what makes the Sigma DP2 Merrill special, we need to first understand how a traditional digital camera sensor works. The sensor is made up of pixels, which is, essentially, the smallest area on the sensor that make up the image. Think of a pixel as a piece of a jigsaw puzzle, except every piece is square. When you combine all the squares together, you get an image. Looking at one square alone will not make sense. Generally, the more squares, the more detail there is (though there is a limit and this isn’t always true). This is called resolution. So a camera with 10 megapixels has 10 million little squares that make up the image. On a normal digital camera, the sensor is monochromatic meaning that it can only see in black and white. In order to capture color information, a color filter array is placed on top of the sensor to only allow red, green, or blue light to reach the sensor. There are many different types of filters, but the most common is known as the Bayer-filter array. It was invented by Bryce Bayer of Eastman Kodak. He designed the filter array to bias green light, like the human eye. Using his filter-array, 50% of the pixels receive green light, 25% receive red, and 25% receive blue. This means that each pixel only sees either green, red, or blue light, but never the other two colors. Looking at the image below, you can see how a Bayer-filter arranges it’s colors. In order to make a complete image, an algorithm is applied to the raw data which interpolates the missing color information from each pixel (this is called demosaicing). To put it more simply, the camera attempts to calculate what amount of green, red, and blue light is at each pixel by looking at the pixel next to it. The calculation is not 100% accurate, of course. A consequence of this demosaicing process is that you can get artifacts (visual errors) in the image such as aliasing or moire (errors with complex textures and patterns such as clothing). In order to combat this, traditional camera sensors require yet another filter known as an anti-aliasing filter. The combination of the anti-aliasing filter with Bayer-filter lower the effective resolution (fine detail) of the final image.
Enter the Sigma DP2 Merrill. This camera uses a completely different type of sensor known as the Foveon X3. The Foveon X3 sensor was invented by Richard Merrill (Sigma added Merrill to the camera name to commemorate him). Instead of using a black and white sensor with multiple filters on top, a Foveon X3 sensor is really 3 sensors stacked on top of each other. Each sensor captures either green, red, or blue, but because they are stacked vertically, every pixel receives full color information (see image below). The benefits of this approach is that there is no interpolating between the pixels (no need for demosaicing). This completely negates the need for a color filter (such as a the Bayer-filter) or an anti-aliasing filter. So, in addition to each pixel receiving full color information, the lack of filters means that the overall resolution (fine detail) is improved compared to an equivalent sensor that uses a Bayer-filter. So although the Sigma DP2 Merrill has 15.3 megapixels, the actual final resolution is much higher (Sigma claims 46 megapixels, though this number is not important, only the fact that the camera outputs more detail than the megapixels suggest). The result is highly detailed and unique photos full of color that have often been compared to traditional film, with some people even calling the camera a digital film camera.
It is important to note that one sensor type is not, necessarily, better than the other. Both the Foveon X3 and Bayer-filter sensors have their purposes. The fact that most people shoot with Bayer-filter cameras means that shooting with a Foveon X3 camera such as the Sigma DP2 Merrill will make your photos a little more unique.
- Miguel Lazaro (friend, pilot, engineer student, photography by hobby)
The DP2 has a fixed prime lens camera with a 30mm, 2.8f lens that is equivalent to a 45mm on a 35mm camera. So this is something I am used to using - as all my cameras have a 50mm lens. I solely shoot with this lens.
Now, I don't know about you - but I adore film more than digital, but it does get tedious and expensive to maintain. So I switch between the two. So to know that there is a camera - and a small point and shoot at that, that captures digital like film - is a dream come true. I have only just started playing with it so the you'll have to check back as I progress with the camera and keep testing it out in different situations.
I have been reading up on it and many sources, including my friend, tend to say that it is best to keep the ISO at the very maximum below 800 as it starts to grain very badly after this point. However, I am someone that really doesn't mind grain and will often put grain in my digital photography. This is something I will have to experiment with as I go along.
This camera comes with two batteries as the battery life is supposedly not very good, however, I tend to shoot my digital like film, and one of the things that attracted me to this camera in the first place, was that I would have to think and compose the shot and really want the photograph I was taking, before I took it. This is very much like film photography, since you don't want to waste your film.
As the sensor captures the whole RGB spectrum, it does take a few seconds for it to process the image, which again, people who want to photograph things quickly, such as movement, or in quick succession, may not find this camera ideal.
The thing this camera is known for is the quality of the image. It is so sharp it is incredible. In black and white it is also so crisp and not necessary to post-process as the colours are so accurate. It has the ability to capture true blues with a setting especially dedicated to blue skies.
For now, however, I took some quick example shots for you to see. I took all of these in Aperture priority mode.
The downside of this camera is that you have to use the SIGMA Photo Pro software to process and edit the raw files - however I have been converting them as TIFF files and then editing them in Adobe Lightroom.
Side by side
Low light at ISO 800
Considering I was shooting handheld in low-light and at these incredibly slow shutter speeds, something I would never consider doing with my Sony, I think they came out pretty good and relatively sharp considering!
Stay tuned as I continue to travel with it. I feel as though this camera will be used more for landscapes, portraits and general street photography, and a handy carry-around without having to lug my Sony A7II around (which I adore so so much but the lens is currently on an adapter and is very clunky to carry around). I will stick to the Sony for closeups, and low-light photography. Film will remain always with me especially for bright sunlight. Remember to follow me on Instagram.