Many people have never even heard of “bit depth” so they don’t know what it means to them and their photography. Even if you have heard of it, maybe you don’t fully understand it. I didn’t, at first. Here’s what I have learned:
Bit Depth Explained
The “bit depth” refers to the number of digital bits of data that the camera captures or that is contained in the image file. Digital SLR (dSLR) cameras capture digital information that is typically of 12-bits at a minimum and 14-bits for high-end dSLRs. This is known as the “RAW” data and is contained in a RAW file. For 12-bit files, this translates to 4,096 levels of brightness in the image file. For 14-bit this is 16,384 levels of brightness.
Why RAW Files Are Best
If you capture and process your camera photo files as RAW files, then you get all of the data that the camera captures and all of the levels of brightness available in the image. This means you can fine tune those levels of brightness in post-processing.
The Inferior JPEG File
If you capture or post-process your images as JPEG files you only get 8-bits of data. That is only 256 levels of brightness. This makes a much simpler image, smaller file, but allows only coarse adjustments with coarse transitions in brightness levels within the photo. In short, with less data utilized, the image will not look as good as a RAW file captured at 12-bit or higher.
If you process or capture as JPEG files, you are essentially throwing away most of the data that your camera captures, and this will result in an inferior photo.
If possible, always capture and process RAW images for the best image quality possible.
While processing files, it may be necessary to save them in a format that is not RAW because many image processing programs will not save RAW files. This is because RAW files and their information are proprietary to the camera manufacturer. Even “universal” RAW files such as DNG files are not easily saved by most image processing programs. What is the alternative? TIFF.
TIFF files are loss-less (no data is lost) if saved in 16-bit format, and should be used to preserve the brightness levels of any image.
The bit depth of photos is important because it determines the levels of brightness available in the images and is a measure of the intrinsic image quality. Always try to capture and use images at the highest bit-depth available and you will get the best image possible.
Thank you for reading what I wrote – I hope you enjoyed it!
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