Introduction: Why the DP1 is unique.
Compact cameras are the obvious choice for lightweight backpacking due to the low weight and size. Digital cameras have advantages over film cameras, too, as there’s no need to carry films (at a weight of 0.8 oz per roll) or struggle with changing films with cold fingers whilst keeping the camera protected from sunshine, dust, snow or rain. Most film compacts use the same film as bigger SLR cameras and the best film compacts can achieve the same quality photographs as an SLR. This is not true with digital compacts because the sensor is much smaller than that in any DSLR. The Ricoh GR-D II, one of the most highly rated digital compacts, has a tiny 7.18 x 5.32 mm sensor, while the Canon Rebel XSi/EOS 450D has a 22.2 x 14.8 mm sensor and a full frame DSLR like the Nikon D700 has a 24 x 36 mm sensor (the same size as 35mm film). The size of the pixels that collect the image data has to relate to the size of the sensor so a digital compact has much smaller pixels than a DSLR. For complex technical reasons large sensors and large pixels produce higher quality images than small sensors and small pixels (if they didn’t there’d be no need for full frame DSLRs let alone medium format digital cameras). So, a 12 megapixel (mp) DSLR will produce a better image than a 12mp digital compact. In fact, so big is the difference, that a DSLR will produce higher quality images than a digital compact with more pixels.
DP1 rear panel showing screen and controls.
There is also the question of noise (speckling on the image). The sensitivity of digital cameras to light is known as the ISO (also used for film speed, which is film’s sensitivity to light). Low ISOs (50, 64, 100) produce high quality images but require slow shutter speeds. High ISOs (400 upwards) don’t produce as high quality images but faster shutter speeds can be used. This is important when backpacking as images may be taken in poor light and when the wind (or being out of breath!) makes it difficult to hold the camera steady. The difference between noise at high ISOs between digital compacts and DSLRs is great due to the tiny sensor as noise increases with both lower pixel size and higher sensitivity. Even the best digital compacts produce noisy images at speeds above 200 ISO while DSLRs can produce images with little noise at 800 ISO. Images from my 6mp Canon 300D DSLRare virtually noise-free at ISO 400; those from the 8mp GR-D compact have noticeable noise.
DP1 rear panel compared with the Ricoh GR-D rear panel. The GR-D has better laid out controls that are easier to see.
The obvious solution for producing DSLR quality images from a compact camera would be to use a DSLR sized sensor. However this is technically difficult and also, I suspect, unattractive to camera makers who see the compact and DSLR markets as separate and would like to keep them that way. (Why buy a DSLR if a compact can do the same job?). So tiny sensors stayed in digital compacts, meaning you had to choose between light weight and low bulk or high quality images. Until the DP1, the first and so far only compact camera with a near DSLR size sensor, came along. Its sensor measures 20.7 x 13.8 mm, much closer to the Canon XSi sensor than the GR-DII sensor. And the image quality is similar to that from a DSLR even at high ISOs. Indeed, the same sensor is found in the Sigma SD14 DSLR.
The DP1 rear panel showing the open menu.
This image quality is the main reason to consider the DP1. It’s the only compact camera that can compete with DSLRs. Unfortunately however other aspects of the camera are not so good, as I shall describe below.
|Pixels:||14.06 mp (2652x1768x 3 layers)|
|Lens:||F4 16.6mm, 35mm equivalent 28mm|
|Dimensions:||112 x 65 wide x 57mm deep|
|Sensor size:||20.7 x 13.8mm|
|Screen:||230,000 pixels, 2.5 inches diagonal|
|Shutter:||15 seconds to 1/2000 second|
|Aperture:||F4 to F11|
|ISO:||50, 100, 200, 400, 800|
|Exposure modes:||Manual, Auto, Program AE, Shutter AE, Aperture Priority AE|
|Metering:||evaluative, spot, centre weighted|
|Image Format:||Raw, JPEG Fine, Normal & Basic|
|Sigma Weight:||250 grams without battery and memory card|
|BPL Weight:||255 grams without battery and memory card|
|Accessories:||Sigma VF-11 viewfinder: 14 grams. $149
Li-on BP-31 battery: 29 grams, $20
|Megapixels:||A Curious Puzzle|
Sigma says the DP1 is a 14.06mp camera. Open a DP1 raw file in Sigma Photo Pro software, which is provided with the camera, and the size will be given as between 10 and 18mb, depending on the detail in the image. Open the same file in Adobe Photoshop Lightroom and the size will be given as 4.6mp. What is going on? The answer lies in the sensor type and the definition of the word "pixel". "Pixel" can mean either the photo detector or the location of that detector. All digital camera makers except Sigma use Bayer sensors which, put very simply, have red, green or blue pixels (photo detectors) that are combined when a photo is taken to form an image. The pixel count is the total number of pixels on the sensor. Sigma uses a Foveon sensor that has three layers of photo detectors, each collecting red, green and blue colors. A section through each layer counts as one pixel location. Thus there are three pixels at each pixel location. How many pixels an image has depends on whether you take the photo detector or location figure. Each Foveon layer is 2688 x 1792 pixels, or 4.65mp. There are three layers so Sigma says there are 14.2mp in total. Others say that as there is one pixel location per three photo detectors at each pixel location and the image file size is 2688 x 1792 there are only 4.65mp.
This 400 ISO image, converted from a raw file, has good colors and a smooth, natural look. 1/1250 seconds at f5.6.
Does this matter? Zealots on both sides argue passionately and interminably that it does. For those of us interested in the actual images I don’t think it’s significant. In terms of quality the DP1 produces images that are comparable to the 12mp Canon XSi/450D DSLR and far superior to those from any other compact camera, regardless of the number of pixels. How much the Foveon sensor affects this is debatable but my view is that the sensor size is far more important. What’s clear is that the DP1 produces images of a higher quality than expected from a 4.6mp sensor. Foveon devotees argue that Foveon sensors produce "better" images than Bayer sensors. I can’t say that I can see any meaningful difference when Bayer and Foveon images of the same scene are processed in the same software.
Description & Usage
The complex detail of this tree is captured well at ISO 100, 1/25 at f8. The camera was hand held. Using the viewfinder made it much easier to keep it steady.
The DP1 is a rather subdued black compact that doesn’t stand out in any way. Nobody notices you using this camera. The rectangular body has a rather old-fashioned look to it. There’s no hand grip, not even a slight bulge in the plastic, but it’s still comfortable to hold.
Unlike many compacts the retracted lens is not flush or almost flush with the body and protrudes some 20mm. Even so, with dimensions of 112 x 65 wide x 57mm the DP1 is quite small and can be easily carried in a jacket pocket or in a small pouch on a belt.
This image taken in woodland in bright sunlight with great contrast between sunny and shaded areas shows that the camera can capture details in these situations. ISO 100. 1/25 second at f8.
The lens does not have an automatic cover when retracted. A separate lens cover is provided, attached to the body with a short piece of string. This cover is slightly awkward to fit and can blow about in the wind when not on the lens. However untying it would probably lead to loss, at least in my case. There is an accessory from Sigma called the HA-11 available which has a collar with a 46mm filter thread and a lens hood so filters could be used instead of the lens cap. I haven’t tried this.
The DP1 lens is a fixed 16.6mm, which is equivalent to 28mm in 35mm. This is a moderate wide angle lens. Any fixed lens has limitations of course but 28mm is good for landscapes. (Sigma has announced that there will be a DP2 with a 24.2mm lens, equivalent to 41mm in 35mm, so there will be an option for those who find the DP1 too wide). The lens has a maximum aperture of f4, which is quite slow. In low light a high ISO and slow shutter speed are required.
On a dull day the colors on this hillside have come out well and there is detail in the cloudy sky. ISO 100. 1/80 at f5.6.
The LCD screen is reasonably bright and a reasonable size. However it is quite grainy and, peculiarly, it turns monochrome in low light. It also smears more easily than other screens I’ve used (they all smear to some extent). As there is no viewfinder the screen is used for composition. In bright sunshine this can be difficult as the image is hard to see. Also it is harder to hold the camera steady holding it out so you can see the screen rather than having it to your eye. There is an optional viewfinder available, the Sigma VF-11. This is tiny and ultralight but quite expensive. It has frame lines, which are not completely accurate but which act as a guide. It does not show any exposure information of course. Using the VF-11 does make picture taking a two-stage operation – check the exposure on the screen and make any alterations then bring the camera to the eye – but I prefer using it, both for more accurate composition and for stability.
There are five exposure modes, selected by a dial on top of the camera. The mode, the aperture and the shutter speed are shown clearly on the screen and can be changed using the right and left arrow buttons on the camera back. I prefer to use manual mode as this gives the greatest control but the other modes are accurate in even light.
Most of the controls are on the back of the camera and here there is an amazing example of poor design. Who ever thought that black letters and symbols on black buttons was a good idea? Presumably a designer concerned with appearance rather than function. As it is, memorizing the button functions is a good idea as it’s hard to see the black letters and symbols in anything other than bright light. Oddly some of the buttons do have white labels. Why not all of them?
A difficult shot straight into a low sun has been handled well by the DP1 at ISO 50, 1/640 seconds at F5.6.
The button in the centre of the arrow buttons brings up the menu. This appears on top of the live image if you don’t switch the latter off first. Many of the features you might often change are in the menu and it is a fiddly and time-consuming business to do so (and difficult with thin gloves on and impossible with thick ones). When the camera first appeared the ISO setting, which most users will probably use often, was in the menu. However a firmware update means the two zoom buttons, used for viewing images on the screen at different sizes, can be set to change different settings including ISO. I have one set to change the ISO and one to change the image quality. This improves the ergonomics a little but compared with the GR-D and the 450D changing settings on the DP1 is still more awkward and slower.
The firmware update also introduced 50 ISO, which does produce very fine images, but 1600 ISO for low light photos would have been more welcome.
There are three metering options – evaluative, centre-weighted and spot. Evaluative works fine for landscapes and I use this most of the time.
The auto focus is accurate but slow. There are single and continuous drive modes but the latter will only take three shots before it stops to write the images. It takes around 6 seconds to record a JPEG image, 8 seconds for a raw image. This is not a camera for action photography. There is a manual focus option, operated by a wheel with a scale running from 0.3 meters to infinity. The same scale appears in the viewfinder when manual focus is selected. If the manual focus is pre-set there is no focus or shutter delay but you still have to wait for the image to be written. I’d still set manual focus if I thought I might want to take photos quickly.
A partly shadowed snow and rock scene caught well at ISO 100, 1/320 at f5.6.
The DP1 will take three sizes of JPEG or raw files. I can’t see any point in using anything other than the best (Fine) JPEG or raw with a camera like this unless there is a shortage of card space. The camera uses tiny SD, SDHC or multi-media cards. A 4GB card will hold around 258 raw images or 1225 Fine JPEGs. Cards weigh 2 grams each.
I viewed JPEGs in Sigma Photo Pro (SPP) and Adobe Photoshop Lightroom 2.1 and found the results somewhat erratic, with some images dull and flat and others luridly bright. The contrast, sharpness and saturation can all be altered in-camera to change the appearance of the JPEGs. The best results come from raw files though. I processed these in both SPP and Lightroom and obtained more detail and more accurate colors than with the JPEGs.
A crop from left centre of the previous image has good detail in the cliffs and the snow.
The DP1 has a histogram but it is disappointingly small and hard to read. There is no live histogram when viewing the live image either nor any highlight warnings when viewing the playback image. The histogram can be a valuable tool for accurate exposure and I use it rather than the exposure meter. With the GR-D I can see a live histogram and alter the exposure before taking the photo while with the 450D I can view the histogram with any blown highlights indicated on the playback image after taking the image and retake the photo if necessary (the 450D also has a LiveView feature but it’s slow to use and I only do so when using a tripod). The DP1 histogram can sometimes be useful but with some images the line is almost flat and it can be impossible to see if it runs off the right side, showing overexposure and blown highlights.
There is a small pop-up flash operated by a small lever. With a maximum range of 4.3 meters (at ISO 800) it’s limited to close-up objects.
The DP1 uses a small lithium-ion battery that Sigma says will take around 250 images at 25°C. This is the same as the GR-D battery but much lower than the 600 claimed for the 450D, which of course has a larger battery. Apart from the fact that the temperature may often be well below +25°C if you playback images often or use the flash the number of images per battery charge will be less. I minimize screen use on trips of more than a few days. I also carry a spare battery. On a trip of more than a week, which I have yet to take with the DP1, I would carry at least two spare batteries. There is a battery life indicator but it isn’t very accurate (something I’ve found with other digital cameras). Overall I’m getting about 200 images per battery charge, without much flash use but without paying particular care to screen use.
A self-portrait with the DP1 on a tripod. ISO 50, 1/80 second at f10.
- Unique large sensor in a compact
- Excellent resolution
- Superb detail
- High quality lens
- Good high ISO images
What’s Not So Good
- Colors fade at high ISOs (can be corrected in software)
- Fixed 28mm lens
- Slow lens, maximum aperture F4
- Low resolution screen dull in low light and hard to see in bright light
- No live histogram
- Histogram too small and hard to interpret
- No highlight warnings ("blinkies") in review image
- Slow image recording
- Almost impossible to read black symbols on black buttons
- Too many features hidden deep in menus
- Highest ISO only 800
- Lens cap awkward to put on and blows about in the wind
An extreme crop of the figure in the previous image still has good detail and color.
Despite the greater number of negative points compared to positive ones I like the DP1 because of the image quality. No other digital camera anywhere near as light or compact as the DP1 will produce such good photographs. Yes, the operation of the camera is slow and clumsy and can be infuriating. For this I much prefer the Ricoh GR-D, one of the best designed cameras I have ever used. But once I see the images from the two cameras there’s no contest and I’ll take the DP1 every time. That is, for landscapes. The slowness of the camera means it’s useless for any action shots. Camping shots where people are not moving too fast are possible but if you want grab shots of your companion spilling dinner or leaping over a stream you’ll miss them with the DP1.
To gain the most from the DP1 raw should be used and time taken over the photographs anyway. This is not a point-and-shoot but a camera for photographers who think about settings and don’t mind altering controls and delving into menus. In that sense it’s a camera for serious photographers rather than snapshooters. You need to be happy with a fixed wide angle lens too.
Do you need such high quality images? For web use and small prints compacts with small sensors will be adequate as long as low ISOs are used. But for large prints and high ISO photographs the DP1 is the only compact really worth considering.
Dusk in the mountains. The DP1 has captured the snow and the sky well in this fairly low light shot. ISO 200. 1/50 second at f5.6.