RAW versus JPEG
This image was taken just over a year ago and was one of a series of pictures of an old poultry barn not too far from here. In response to my previous post, several folks commented that the HX9V was a pretty good little camera. Yes, perhaps, but when put to the test, as it was here, you can see that it isn’t able to keep up with a full-frame DSLR. The image sensor in the HX9V measures 6.17 X 4.55 mm with an effective resolution of 4608 X 3456 pixels or 16.2 effective MP which means that each light gathering unit has an approximate dimension of 1.33 µm. The image sensor in the D600 measures 35.9 X 24.0 mm with an effective resolution of 6016 × 4016 pixels or 24.3 effective MP which means that each light gathering unit has an approximate dimension of 5.97 µm. Therefore the Nikon has larger light-gathering units and many more of them and this will allow the D600 to take pictures in lower light and to gather much more information than the HX9V. To pursue this further consider that the Sony is not capable of recording images in RAW format, the D600 is. So, what? The following is from a piece which appears at the SLRLounge and it is presented here in an edited form. JPEG files are processed within the camera. While color and exposure are established by your camera settings the camera’s own firmware will process the image to add blacks, contrast, brightness, noise reduction, sharpening and then render the file as a compressed JPEG. Because the image is compressed, JPEG is a “loss” file format, much of the initial image information and detail is discarded and cannot be recovered. You may hear the term “Dynamic Range” used when discussing RAW files vs JPEG. Dynamic Range is simply the amount of tonal range from the darkest shadows to the brightest highlights. Dynamic Range detail in JPEG files is significantly reduced as compared to RAW files. The following is from a piece which appears at the Digital Photography School and it is presented here in an edited form. The major player in the process of image compression is the Discrete Cosine Transformation (DCT) which divides the image into blocks, of usually 8 × 8 pixels, and determines which can be “safely” thrown away because they are less perceivable. And when the image is put back together, a row of 24 pixels that had 24 different tones might now only have 4 or 5. That information is forever lost. So the bottom line to all of this is that JPEG images are much smaller than RAW images (in terms of file size), they look pretty good on your camera’s LCD, and can be taken in very quick succession. RAW files are much larger, take up more room in your camera’s memory card, look only OK on your camera’s LCD, and cannot be taken in very quick succession. Because a RAW file captures more information than a JPEG file the former can produce a final image with much more depth and range. To get the most out of a RAW file however it will require post-processing. JPEG images can be viewed and printed immediately, as is, without any post-processing. Clicking the image here will provide a larger version for you to view. I don’t like to nitpick but the clarity, the depth and the range, simply aren’t up to the standards set by a full-frame DSLR.