White Balance

The SD9's automatic white balance proved to work very well, even under incandescent light (which is normally beyond most digital cameras) balance was good with no visible hue shift. The pre-programmed white balance settings also seemed to work well, remember the beauty of RAW files is that you can always alter white balance later. Manual preset of course gives the best results. Note the desaturated look of images shot under fluorescent light, this is not unusual.

All JPEG's provided in this section of the review were output directly from Sigma Photo Pro.

Photo Pro Adjustments: Default

Outdoors, Auto Outdoors, Overcast Outdoors, Manual
Incandescent, Auto Incandescent, Incandescent Incandescent, Manual
Fluorescent, Auto Fluorescent, Fluorescent Fluorescent, Manual

Night Exposures

Night Exposures with the SD9 were disappointing, there were a number of problems with images taken with a long exposure. Firstly because of the affects of 'pin point' overexposure (lights on buildings) you will often get very large over exposed discs which can sometimes carry clearly visible chromatic aberration. The secondary affect of this overexposure is to push the sensor / Photo Pro into loosing color information around the highlight (color clipping). Another strange phenomena was the odd 'glow' around bright areas of the image, sometimes with color other times just luminance.

All JPEG's provided in this section of the review were saved at the 95% quality level, click here for more information.

ISO 100, F8.0, 8 sec
Photo Pro: Exposure +0.9, Highlight -1.6,
Color 10C+8M
ISO 100, F11.0, 3 sec
Photo Pro: Exposure +0.8, Highlight -1.6, Saturation +0.5, Color 13C+13M
100% crop: Note the glow around the blue lights at the top of this building 100% crop: Here's a good example of color clipping surrounding over exposure
100% crop: Examples of color loss and glowing 100% crop: Example of large discs which emanate from the center of over exposed image areas

Night exposure bug?

One thing the camera did with some consistency was ruin the first shot taken. The two shots below were taken one after another. With the same subject distance, exposure etc. the first shot of a sequence would always turn out like the one on the left below, with a very bright haze. Subsequent shots (without changing settings) would be without the haze.

Photo Pro Adjustments: Default

Overall Image Quality / Specifics

There is no doubt that Foveon have achieved the promise of X3, that is individual pixel color and resolution. The sensor's ability to capture single pixel resolution is astonishing, magnified X3 images look like most unlike any other digital camera image you're likely to see. They're sharp at 100%, far sharper than any Bayer pattern sensor would be capable of and certainly achieving levels of resolution far beyond the 3.4 million pixel label. They actually remind me of a higher resolution image downsampled, and of course that single pixel resolution / color response is exactly what you could achieve from a high megapixel Bayer pattern sensor downsized 50%.

Looking at the resolution charts it's also interesting to note that the X3 continues to capture 'some detail' beyond its absolute resolution limit, this means that for example rather than returning a soft blurred surface it's still capable of reproducing texture and detail at very high resolution.

Color response was also on the whole good, the X3 sensor does have a tendency to respond very strongly to blue skies, in several shots we took the blue of the sky was far stronger in the image than in reality. I also noted that green response was more muted than other digital SLR's.

All things considered however the X3 isn't without its share of problems, it does seem fairly clear from looking through our hundreds of test shots and comparing its performance to other more mature digital SLR's that the X3 / Photo Pro software still needs some development. See below.

All JPEG's provided in this section of the review were saved at the 95% quality level, click here for more information.

Unnatural blue skies

As noted above the camera / sensor would on occasions produce extremely deep blue skies. While this can be desirable as an after-effect it certainly didn't seem accurate and did leave me doing a double-take of the image on the LCD screen and what my eyes were seeing. (Read note about UV filter use below).

Photo Pro Adjustments: Default

Chromatic Aberrations

There has been much talk on our Sigma SLR Talk forum about chromatic aberrations in SD9 images. It was clear that one of the reasons behind this was that X3's ability to 'see' the tiny effects of chromatic aberrations along the edges of highlights was far better than a traditional Bayer sensor.

Photo Pro Adjustments: Default

Color clipping

This is something I touched on when talking about Photo Pro, however looking through more and more images I'm starting to believe it could be a sensor problem. Essentially the X3 sensor appears to lose all color information once one of the color channels reaches saturation (becomes over exposed), at this stage the color of the pixel simply turns grey (or white) leaving a very unnatural looking artifact. This means that you have to be more careful with your exposure, not always easy.

Whether this can be fixed in Photo Pro (at the time of processing) or whether it's a sensor problem isn't yet clear.

ISO 100, F8.0, 1/125 sec
Photo Pro: Default
ISO 100, F8.0, 1/250 sec
Photo Pro: Exposure +1.3

Softness / color saturation at higher sensitivity

This is quite subtle but shooting at ISO 200 or 400 softens the image very slightly and can lower the saturation of certain colors. I first noticed this when taking a sequence of shots at ISO 100, 200 and 400. Looking through more and more ISO 400 shots it became more apparent. It's not clear at this stage whether this is an effect of pushing the sensor up in sensitivity or automatic noise reduction in Photo Pro. While not severe, and probably not noticeable in the majority of shots it is worth noting. Also some Kudos for the lack of noise in the ISO 400 shot below.

Photo Pro Adjustments: Default

ISO 100 ISO 200 ISO 400