Pentax *ist DS Review
Software (contd.) - RAW conversion
JPEG & RAW Resolution compared
We learned fairly early on that the *ist DS's built-in image processing was sadly lacking, initial resolution chart shots were disappointing and certainly compared to other six megapixel digital SLR's the performance is below par. That was until we developed a RAW image of the chart, the difference is like night and day, especially using Adobe Camera RAW. A JPEG from the camera manages about 1400 LPH horizontally, convert a RAW through Adobe Camera RAW and the resolution lines are clear and visible all the way down to 1550 LPH without any artifacts.
|Pentax Photo Laboratory
RAW -> TIFF (Bright mode)
|JPEG from camera||Adobe Camera RAW
RAW -> TIFF
Shoot RAW, get the most from the *ist DS
It's disappointing to find that the camera's built-in image processor is throwing so much detail away, the sensor is clearly capable of capturing very good resolution but for some reason this is being destroyed by poor bayer interpolation or excessive moire reduction algorithms. Whatever the reason the *ist DS is transformed if you stick to RAW, especially if you use Adobe Camera RAW (via Photoshop CS). The difference was so stark that we chose to shoot RAW for many of our gallery images (we wouldn't normally do so).
While the saturation level of Photo Laboratory in Bright mode is similar to JPEG the RAW conversion maintains more detail on the tips of the red crayons than the in-camera processor manages. Photo Laboratory in Natural mode is quite similar in response to Adobe Camera RAW.
|JPEG||Lab - Bright||Lab - Natural||Adobe Camera RAW|
RAW demosaic artifacts
Something we observed fairly early on were noticeable demosaic artifacts which can be seen along the edges of detail in RAW images converted using Pentax Photo Laboratory. As you can see from the 200% crops below these artifacts do not occur in JPEG from the camera or Adobe Camera RAW converted RAW images.
|Classic Cruisers by Surfwalker|
from Song Titles- Little Deuce Coupe
|_F0A5334-Edit_small by Dester Wallaboo|
from Open Air Fashion Photography
|Gosford Reflections DP by MarioSS|