I am bit confused. If my DSLR is capturing 14 bit image while shooting RAW. Don't I need a 14 bit monitor also to take full advantage of capturing in RAW? Whats the point of capturing an image in 14 bit and open and edit it only 8 bit depth monitor?
You could edit your photos with an old burned CRT black and white monitor and it still is the same matter: the additional bits count.
Here is a simulation of a 14 bits histogram (A) and an 8-bit one (B). Both are over a blue grid that simulates an 8-bit display or 8bit file format.
In B, all the lines coincide. (8-bit format is good enough because is close of what our eyes can perceive in different gray levels)
Now. Imagine that you need to move your histogram because you want a brighter happy picture.
The different levels on the left side, slide to the right.
On your raw file there are enough "sub-levels" to fill the same blue lines. (C).
But the data on the 8-bit image starts forming "gaps" (red zone). This will create banding problems, increased noise etc.
So the important difference is when you manipulate or control your image, and you do have additional data. This gives you freedom.
Higher bit depths give you more options for editing without losing data.
Don't make the mistake of tying the representation of an image with how it is rendered. Editing yields the best quality results when you operate on the representation, where the underlying data has the highest resolution. It just so happens that your monitor provides a lower resolution view of the image but this is not tied to the quality of the underlying representation.
If you recall from school math, there was always a rule of thumb: Never round intermediate calculations when computing results; always perform the math then round at the end when you present the results. The exact same thing applies here. Your monitor is the end, where the "rounding" takes place when presenting it to you. Your printer may "round" differently. But in all intermediate steps you use the raw data for the most accurate results, and you store the original high resolution representation on disk so you can maintain that information and continue to do accurate editing later.
Consider this: Say you have a 5760 x 3840 source image. You'd maintain the most editing and rendering flexibility by editing the image at that size and leaving it that size. If you happened to be viewing it on a 1440 x 900 monitor you'd just zoom out in your editor, you probably wouldn't actually resize and resample the data to get it to fit. The same exact thing goes for color resolution.
Audio is similar. Perhaps your computer's sound card only has 12-bit output capabilities. But if you record, store, and operate on 16-bit or 24-bit audio, you could make a low volume signal 16x or 4096x louder (respectively) and still achieve minimal loss of output quality on that computer. Convert down only at the end when you're about to present the final result. The visual equivalent is brightening an extremely dark image with minimal banding.
No matter what the capability of your monitor is, if you perform an editing operation, e.g. multiply the brightnesses by 2, you want to perform that on the original high resolution representation of the image.
Here's a simulated example. Let's say you took a really dark picture. This dark picture is the top row below, with simulated 4-, 8-, and 14-bit per channel internal storage formats. The bottom row is the results of brightening each image. Brightness was multiplicative, scale factor 12x:
(Source, photographed by Andrea Canestrari)
Note the permanent information loss. The 4-bit version is just an illustrative example of an extreme. In the 8-bit version you can see some banding particularly in the sky (click image for expanded view). The most important thing to note here is that the 14-bit version scaled with the highest quality, independently of the fact that its final output form was the 8-bit PNG I saved it as and of the fact that you are likely viewing this on an 8-or-less-bit display.
14bit Raw does not correlate to your monitor's bit depth. Raw is a format that is minimally processed. See Raw Image Format.
Raw format allows post processing software such as Lightroom and Photoshop to make fine adjustments to images that would not be possible with JPEG files.
As far as the monitor, wide-gamut monitors are usually 10bit and have an internal LUT that stores calibration information from calibrators like X-Rite or Spyder. Your video card needs to be able to support 10 bit as well.
For Nvidia chips, workstation class cards support 10bit. Most, if not all Gaming-class cards do not from my expereience. It is similar with AMD chips sets.
If you are not going to post-process your images, then you can easily switch to JPEG.
You should maybe read this question first.
Basically, the dynamic range of paper is less than 8 bits, and the dynamic range of the human is not dissimilar.
The advantage of high dynamic range in RAW images is that you can post-process them to bring the bits you're interested in within the range that the display device can represent - which in turn relates to what the human eye can see.
So the classic example is an room interior with sunlight outside. As the human eye switches from looking at the interior to the outside, the iris contracts to reduce the amount of light coming in, allowing you to see outside details as well as interior details.
A camera doesn't do that, so you'd normally have to expose either for the room interior (and getting blow highlights), or for the outside (getting an underexposed interior) - or take two shots and make an HDR composite.
The higher dynamic range of Raw allows you to take a single shot, and selectively 'push' or 'pull' certain areas to reveal detail that's in those over/under-exposed areas.
The shots here show this kind of scenario. https://www.camerastuffreview.com/camera-guide/review-dynamic-range-of-60-camera-s
The 'Wikisperts' forget that whatever bit depth you process in, you ONLY see the result in 8 bit. Stick a 3bit file (8 levels) into your 8 bit system and the display will show 8 levels (256/7 = 0 to 7) 0 to 255 in steps of 36. A 4 bit will show 16 (0 to 15). Stick a 10, 12 or 14 bit file in you will see 256 levels. Your video card will convert the 1024, 4096 or 16,384 levels down to 256. This is why, watever RAW file you load, as soon as it is offered to your video processor it becomes 8 bit(256) levels. I worked in Medical physics, most imageing departments now have 12 bit imaging for breast screening and the like. However, the human eye can't detect better than 900 ish levels so software is used to detect minute changes in tissue density so if you meet someone who has a 10, 14 or 14 bit system, they will be heavily in debt and mega dissapointed. Incidently, we also struggle to detect changes in colour, our vision rolls off below 16Million colours unless minute changes in a similar hue, where we notice banding. Our camera's are capable of some 4 Trillion colours but like many things, whats theoretically possible and actually possible can be two very different animals.