Summary: I'll start with the bad news. In low light, the Foveon sensor used in all Sigma digital cameras is not as good as the Bayer sensors used in all other digital cameras. Besides that, the quality of the SD15 photos in good light is better than any other camera can produce, no matter how much money you spend. I'm including both the RAW and JPG images produced by the SD15. Others have claimed that the JPG output of the SD15 is poor quality.
Summary: I think there are too many digital SLR camera's in the market. For example Canon, Nikon, Sony, Pentax and others. All of them are really good and atractive for costumers. As I want to buy Full Frame digital camera, unfortunatelly I haven't still one. many days I have spent lots of hour in the internet and looking for handful cameras. And one day I see Sigma SD15 for a reasonable price and no doubt to take it. Me as I am this camera is the best for me.
The SD15 will teach you a few things about photography.
BSI Eric, Amazon
10 December 2011
Summary: I have gained the most from this camera in the form of education. I am a beginner in digital photography. I didn't know much about shutter speed, etc... I had to learn these things to get images from this camera. I am satisfied with the results I get and the more I learn about photography the better my images get. I really enjoy using the EF 610 DG Super Flash also. It is a must have if you ask me.
Excerpt: After the great experience with the SD14 I can say that the SD15 is even better. Electronic improved, much faster processor, better noise treatment, very smooth in all the aspects. Dynamic range excellent, colors very naturals and reals. Pics looks great . The leaves , flowers , trees at landscapes looks naturals and clears. True colors sharpness and very high definition. Its a marvel. Next step is the SD1 46 mgplxs. but much too expensive yet.
Summary: I received my copy of the SD-15 in July 2010 after waiting for it for 2 months. It came with over 1000 shots already in the shot counter, but with a new camera warranty from Sigma USA. Don't settle for anything less than a totally "legitimate" purchase from a real dealer. I didn't: the Sigma USA warranty was the important thing. When I got it, I also got a Sigma 50-200 F4-5.6 OS lens for what I thought was a too-cheap price of $169.
Summary: I have owned several Sigma cameras and have a love/hate relationship with the breed. To generalize, I find them like an old person---rich in capability but somewhat slow and cantankerous to live with. I rail at my Sigmas but miss them when I leave them home. In any case, I purchased this SD15 to replace my SD14 which had white balance issues that I was tired of dealing with. This slightly refreshed version is vastly better at analyzing light and properly rendering it.
Summary: The people who say this is not a real 14 megapixel camera don't understand how Foveon sensors work. A picture is not just a bunch of dots (pixels), it is a combination of colors and their intensity. While a Canon camera might make JPG files that technically have more megapixels than a Sigma, the amount of color information in the Sigma picture is still better. Also if you think 2640x1760 resolution is somehow not good enough for full size prints then you're on crack.
Summary: I own this camera for 2 months now. The special Foveon RGB sensor without low-pass filter captures sharp images with beautiful tones and accurate colors. I bought it to replace my 35mm film camera and I am very satisfied. If this camera didn't exist, I would not have gone digital. I can highly recommend this product.
Summary: I'm SO tired of these uninformed, quick and dirty reviews of a truly unique and wonderful digital camera system. Any review of the Sigma that doesn't once mention that it is designed primarily to shoot RAW images is far from a serious review. I chose Sigma over all other DSLR systems years ago when the SD9 came out, and I now own the SD14 and SD15 and I haven't regretted it a bit. The color, sharpness and overall camera operation is perfect for what I shoot.
Pros: Best, truest colors. Best native sharpness. Best overall image quality.