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The SD1 has built-in pop-up flash with a guide number of 11. Here it's judged exposure and white balance pretty well.

Perhaps more useful to advanced users is the flash's ability to control Sigma's EF DG Super range of units wirelessly.

Color modes

The SD1 provides a number of preset colour 'looks' that provide a useful range of options. The default 'Standard' option is rather muted (but accurate); if you want punchier output you can switch to 'Vivid' or 'Landscape' (which offers a slightly warmer rendition). Sigma also provides Monochrome and Sepia modes, but mysteriously doesn't allow you to use them when shooting RAW. Sigma Photo Pro offers the same set of colour options for RAW users, but (rather eccentrically) Monochrome appears only as a White Balance option, and Sepia is completely unavailable.

Standard Vivid Neutral Portrait
Landscape Mono Sepia  

Specific image quality issues

The SD1's low ISO image quality can be intoxicating, but the camera requires perhaps more than its fair share of care and attention to maximise the quality of its output. Its biggest problems are its slightly twitchy evaluative metering system and unimpressive high ISO image quality.

Metering and highlight clipping

One of the first things we noticed during real-world shooting with the SD1 was a disturbing predisposition towards overexposure. Press play and your images' histograms will often show extensive highlight clipping. Clearly Sigma recognized this as a problem from an early stage, and has progressively tweaked the metering with multiple firmware updates. But the evaluative metering remains strongly-linked to the selected autofocus point, which means that if you focus on a dark area of the scene it will overexpose.

The example below illustrates how the evaluative metering depends on the selected AF point with a contrasty scene, placing the AF point successively lower down the scene. We've shown screenshots from the camera to show both the active AF point and histogram, and the associated exposure clipping warning, alongside the resultant image files.

Camera screenshots Resultant exposures

What's perhaps most notable here is that, in this case, using the center AF point gives about the closest thing you'll get to a 'correct' exposure, with just a little clipping of highlights and good shadow detail. Selecting an AF point in the top row results in underexposure and blocked shadows, whereas selecting one in the bottom row results in considerable highlight clipping (and as this was shot at ISO 100, the lost detail can't all be recovered from the Raw file - click here for a conversion with -2 EV compensation).

Arguably this should be considered a characteristic of the camera rather than a fault - it's the kind of thing that you'll get accustomed to once you've used the camera for while - but given the inherent characteristics of digital capture, we'd generally prefer to see pattern metering protect the highlights a bit better. Naturally, if you prefer to shoot using a more-predictable metering mode such as centre-weighted average, it's not a concern. And if you shoot at ISO 200 or higher, you get an extra stop of highlight data in your Raw files, which negates the problem considerably.

High ISO image quality

While the SD1 is excellent at low ISO - 100 to 400 - above this its image quality quickly deteriorates, and by ISO 1600 it has serious problems, with unsightly purple-and-green colour blotches in the shadows making many images practically unusable. This is also where the look of the camera's JPEG and Raw images diverges most substantially, as if Sigma isn't even sure about the best way to handle the files.

The example below was shot at ISO 1600, a point at which we'd expect any modern APS-C (or Micro Four Thirds) camera to be entirely comfortable. But the SD1 is seriously struggling. The JPEG and Raw + SPP output attempts to deal with the image noise in somewhat different ways, but neither is truly successful.

ISO 1600, camera JPEG ISO 1600, Raw + SPP 'to taste'
100% crop 100% crop
50% crop 50% crop

The row of 100% crops reveals a significant difference in processing - the JPEG shows all sorts of problems, with low saturation, colour bleeding from the tower to the sky, and large 'grains' of noise. The Raw file handles colour better, and has much finer noise grain in evenly-toned areas, but SPP's noise reduction gives vertical streaking that emanates from from all of the (many) vertical features in this image. The lower row of 50% crops reveals the low-frequency green and purple chroma blotching that seriously bedevils the SD1's high ISO output - the JPEGs appear to reduce saturation to make this less visible, but without much success.

As is often the case, the SD1's high ISO problems are accentuated under artificial light sources, which tend to be prevalent in low-light situations. The camera's also not helped by Sigma Photo Pro's noise reduction algorithms, which don't work terribly well and can leave strange artefacts of their own (such as the vertical streaking seen in the example above, that's more obvious if you download the full-size picture). Overall we'd have to say that the SD1 should be considered a low ISO camera only, as any other current APS-C or Micro Four Thirds camera will do a better job at high sensitivities.

Compared to...

Here, we want to give you an indication of how the SD1 Merrill stacks-up against the competition, in the controlled conditions of our studio. We've used he Sony SLT-A77, which at 24 MP sports the highest resolution APS-C sensor currently-available, the Canon EOS 5D Mark II with its 21 MP full frame sensor, the 18 MP full-frame Leica M9, and the 40 MP medium-format Pentax 645D. The latter two cameras both use conventional Bayer-type sensors but, like the SD1, don't have anti-aliasing filters. We're quite deliberately not providing extensive commentary here - we encourage you to download the pictures, take a good look, and make up your own mind. Note that the 100% crops we've provided for each image don't tell the whole story, by any stretch of the imagination.

Sigma SD1, 30mm F1.4 EX DC HSM, 0.4 sec F8 ISO 100
Sony SLT-A77, DT 35mm F1.8, 1/4 sec F8 ISO 100
Canon EOS 5D Mark II, EF 50mm F1.4 USM, 0.8 sec F13 ISO 100
Leica M9-P, Summilux-M 50mm f/1.4 ASPH, 1/4sec F11 ISO 160
Pentax 645D, smc D-FA 55mm / 2.8, 1.6sec F16 ISO 100
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Total comments: 9

To update a three and a half year old review a little, as a recent convert to the Foveon sensor in this Sigma (albeit in the DP2 Merrill iteration) I can testify that the latest Sigma Raw processing software, Photopro 6.3, which is used for the SD1 Merrill as well ithe DP2, does not leave much to be desired, at least to a relative newcomer to Raw processing. And this running on Windows 7 on an ancient Core 2 Duo at 2.66Ghz with 4 Gb of memory. There may be frustrations for those who wish to devote more time to arcane debate than taking shots, but on the whole Photpro6.3 hits the spot. Hats off to Sigma....


Is this the 24-70 ART lens that you are using ? I have the 28-80 HF and 18-50DC's but the Chromatic Aberration is shocking with these and I cannot achieve a constant colour, without discoloration around the edges. I was thinking of buying an adapter and looking for a better lens, possibly a Nikon one.


Use a full frame lens like the 24-70 F2.8 EX DG HSM. You will get fantastic results. Use it properly - on a tripod at 100 ISO and F8. Have good light. Shoot raw. Convert to 48bit tiff. Edit with the appropriate skill. If the results don't blow you away, your doing something wrong.


I photograph textiles for a living and I have a love hate relationship with this camera. Some of the results are stunning, then at other times it is infuriating. The fact that I cannot Wifi the camera drives me mad,a friend is trying to solder up a device, so I can attach a ribbon cable to compact flash type 1 holder, then have a type 2 WIFI one mounted externally. I am envious of my colleague that works with a Nikon and uses her iPad to control and tether her camera, with an instant review of the post and final image .


If you shoot at 400ISO or less, use the best lenses, shoot raw and use the latest version of the much improved Sigma raw conversion software, you will be able to upsize your clean artifact free files to around 6700 pixels across giving you an equivilant resolution of a 30MP Bayer sensor. I do this all the time and the results are fantastic. Using a full frame lens on this sensor gives you images that are sharp to the corners and almost distortion free. The 24-70mm F2.8 HSM on this sensor enables image quality way beyond anything I ever shot on a 5D2 or 5D3 with L lenses.. When you get to know the tool and develop skill to use it well, the results will blow you away. Most people want it easier than that. You reap what you sew!

1 upvote

I purchased an SD1 for my business of photographing textiles in a studio situation and I feel totally deflated. The actual image quality is excellent, but the tethering capabilities are pathetic. I expected to be able to click from my PC to launch a shot, then instantly see what I had taken, before moving on to the next item, which sadly is not the case. Their software application known as Sigma Capture Pro should be reported to the trading standards council, as there is nothing 'Pro' about it as it is just a glorified remote shutter release program. Furthermore in order to have access to your images on a PC, you need to go into the menu function on the camera and disable the 'remote capture program' then select mass storage to view your images. Going through this process with every shot, may be good for you cardiovascular system, but for someone who relies on seamless throughput to make a living, this camera is junk.


Tethering capabilities? lol. You are more interested in showing off in front of clients than achieving great results. Re-align your priorities. You do realize that 90% of the time the images are used at 400 pixels wide on a web site - do you? you don't need to check each shot at 100% mag on a full size screen before you know you got it. Give us a break with your grandstanding.


I was looking at the photo comparison today, comparing the SD1 against the new Canon 5 D Mk III, the Nikon D800E, and the Pentax 645 D . . . at ISO 800 . . . and I just can not believe my eyes. Take a look at this:

The SD1 never ceases to amaze me.

Scott Greiff

Why won't the comparisons load?

Total comments: 9