Canon G11 RAW Bit Depth

[bill_moeller]

<p>Can anyone tell me what the bit depth is for Canon G11 RAW images? 8? 12? What?<br>

I recently started carrying this camera around with me when I don't want to carry four pounds of DSLR and lens, and am very happy with it except for its tendency to wash out highlights and its high contrast images. I have found ways to deal with these in post processing very carefully exposed RAW images, but am curious about what I am working with. Canon's specs in the manual do not tell me, and it is not as simple as checking RAW file size.<br>

Thanks.</p>

[tangibleimages]

<p>One thing I've found is to dial in -2/3 EV on the camera most of the time to better protect those highlights.<br>

As for bit depth, Canon isn't saying but I suspect it's 8 due to RAW file size.</p>

[jcuknz]

<p>It makes sense to set the camera to under-expose and I am sure there is provision in the menus to reduce the contrast, so that you can add what you want in PP. The alternative exposure technique is to increase more highlight area when first taking half trigger and holding HT while you reframe for the shot you want.</p>

[bill_tuthill]

Interestingly, on DxOmark the G11 has a higher score for dynamic range than the Olympus E-PL1, 11.1 versus 10.1. But the G11 is slightly behind in color depth, and way behind in low light, 169 versus 487.

[dave_redmann]

<p>For whatever it's worth, I seem to recall reading in the CHDK information that most of the PowerShots have raw files (as enabled by the CHDK firmware hack) of 10 bit-per-channel depth. Presumably this is a function of the analog-to-digital converter used. It would not surprise me if the G11 has more bits, but it would not surprise me if it is likewise 10 bits.</p>

<p>But bear in mind that bit depth and ability to recover highlight detail through raw conversion are not the same thing. You can take 5 stops of dynamic range and use 16 bits per channel to encode it--which means very smooth tonality within what it records but lots of white highlights and black shadows. Or you can take 10 stops of dynamic range and use 8 bits per channel to encode it--which means relatively coarse tonality, maybe some banding, but a lot more highlight and shadow detail.</p>

 

[bill_moeller]

<p>Thanks,guys, for your responses. Jake, JC: what you suggest is exactly what I zeroed in on except that I adjust contrast during post processing because I shoot RAW+JPEG and cannot adjust contrast when shooting; -2/3 exposure comp and several notches of contrast reduction before applying a Curves adjustment to restore mid range contrast has done the trick so far. Bill, Dave: your comments help me to understand what is going on here and what the tradeoffs are, I really appreciate it.</p>

[teos]

<p>Bill , try the Bc setting (Func set , select BC ,press DISPLAY and you find the setting for contrast,sharpness,saturation,red,green ,blue, skin tone).<br>

At least , on my G9 this is the path .<br>

Good luck !</p>