Being direct
There are immediate advantages to using a direct image sensor like the Foveon. As there is no need to demosaic the final pixel output – a process necessary in conventional sensors that capture colour data onto one single mosaic-patterned layer. Futhermore, there’s no need for an anti-aliasing filter – normally used to lessen the moiré effect of demosaic process but that lowers effective resolution. The images captured by the Foveon are naturally moiré-free and resolve more data detail than any other equivalent size sensor.

Sigma's utilises its own SA bayonet lens mount type in the Merrill
The upshot of the Foveon approach are images that have an incredible level of detail that outshines any other camera in this class and many full-frame models – at least at low sensitivities. The RAW files, in particular, are in a class of their own with perfectly balanced, natural colours and amazing definition. The JPEGs are also very well resolved in terms of detail and colour but seem to suffer from a consistent and annoying overexposure problem.
The main issue and the real stigma of this camera is that at higher sensitivity, anything from ISO 400 onwards, image quality deteriorates dramatically with unacceptable levels of noise appearing and with pictures generally falling far short of the standard of most APS-C cameras. The technical reasons behind this are too complex to summarise here but they are inherent to the technology employed in the Foveon.

Alloy body and weather sealed too
The peculiarity of a camera that produces top class images at low ISO speed and really poor results at higher sensitivity greatly limits its use in the real world. The SD1 is a camera that will work magic in studio or landscape photography but will be unsuited to most other fields.
Add to the high ISO noise problem the sluggish general operation, the slow and at times erratic autofocus system and the narcoleptic file writing speed and it becomes clear that this camera is not everyone’s ideal imaging tool. The lack of any sort of creative filter, effect and video mode will also seriously reduce the SD1’s allure for anyone but professional and seriously enthusiastic photographers.

Next page: Sample Shots
COMMENTS
Re: Sample shots.
Great collection of sample shots! Really great!
I've been critical of some Reg camera reviews in the past - top work on this one.
The EF mount was used on both film and digital cameras. It replaced the FD mount which was film only. EF-S is digital only - but only because they only do digital now - the EF-S is actually for APS-C sensors, it's about sensor size rather than film/digital.
"they didn't do the Canon trick of changing their mounts for digital, so old lenses still fit)"
Strange I've had two Canon digitals 300D & 550D and the lenses I have are all the usual EF lenses - they have introduced extra lenses that only fit the digital range.
SD1 Failure
IMHO the reason that the SD1 failed was that every with every month that passed, the launch date moved back about 3 months. By the time it was launched, years late, everyone else had something else Canon / Nikon / Pentax, etc. Personally I have Canon. Also the other CMOS / CCD sensors improved a lot in that time, but it seems that the spec for the Fovian sensor was set in stone and has not kept up. By now I have 3 camera bodies, but that is not where my investment is. I can change all the bodies, and all the lenses fit on the new bodies. I will generally keep a lens for (much) more than 10 years. The SD1 won't work with any of my Canon lenses, and even if I had a Sigma lens for my Canons, it still wouldn't work with the SD1. The price of the camera is almost nothing next to the cost of all the lenses.
Very, very poor low-light performance from all of the Fovian sensors doesn't help either, and even though this camera is cheaper than the first, it's still about the price of a Canon 7D or 5D MkII, but is built like the cheapest bottom end camera with controls requiring the vulcan death grip to press buttons and operate dials at the same time. I wanted so much to like the SD1 cameras when they finally came out, but they just make me think of the car of the same name; a footnote in history.
