I'm not convinced that Sigma actually wants to sell cameras . .

xpatUSA wrote:

jrtrent wrote:

xpatUSA wrote:

. . well after a couple of beers, I'm beginning to wonder!

But then, examining a raw histogram, I was amazed to see that the maximum raw level attainable with these two cameras is around 2,300 !!

I mean, the SD9 raw values can be up in the 10,000s the SD10 even higher, then the SD14 more like 9,000 and the SD1M more like a sane 4070 - which almost bears a resemblance to the ADCs output. God knows what the Quattro puts out, something different, I'm sure.

What is a "raw level"? I recently bought a refurbished DP2s from Sigma and am quite pleased with both it and the software it uses (Sigma Photo Pro 4.2), but have no idea what these numbers mean that you posted for the various cameras.

Yes, I will try to explain. When we take a raw shot, which you can do by selecting RAW from the Qs menu on the camera, the in-camera firmware takes all the sensor output values or 'levels', does a bit of scaling and writes the shot as a file of type X3F onto the memory card. In that file, the image data part is called the 'raw' data because nothing has been done to it like applying the white balance and converting the 'raw' data into a JPEG image.

Each sensor pixel location in an image has three 'raw' values or levels, one for each layer. For simplicity, we can say that, in-camera, the level for each layer can be between 0 and 4095 (12 bits), no less and no more. But, the camera does a bit more with that data, including some scaling and writes it to the card so as to fit into 16bits which computers are more comfortable with.

If you look at these numbers with a utility program, you can learn a lot more about how well the camera is exposing the shot - as opposed to what the color-picker says in SPP 4.2. The trouble is that these ranges of levels from min to max are written to the card differently for just about every camera model that Sigma makes.

So "exposing to the right" means aiming for different raw numbers depending on what camera you're shooting. Aiming for good raw numbers because the in-camera histogram is not always the best guide for a good exposure. So, reasonable goals for your DP2s when opened in RawDigger should show levels (highs) of, say,no more than 2300. But reasonable goals for my SD14 might be around 7,000. And an SD1M, around 4,000.

I'm enjoying my DP2s that I received this very week.

I appreciate your explanation.  I'm afraid I don't understand it, but I do appreciate it.  Have to admit I'm not familiar with SPP's color picker either, nor have I used the camera's histogram.  The camera's metering system works pretty well, and I also enjoy my uncle's old incident light meter.