RAW image files, also known as digital negatives, are the dSLR version of an unprocessed image. In film, a RAW file is equivalent to the negative itself in the sense that you can’t really use it as a photo, but all the unprocessed information is there to create a photo. RAW works the same way – you can’t upload a RAW file to your website and expect it to be viewable, but you can create a fantastic photo from it with a bit of processing.
When you record a file as a JPG to your memory card, you’re instantly compressing it before you even bring it into Photoshop – thus losing important data needed for editing. Not only that, your camera may have presets that apply even more effects to your JPG image (such as a contrast or saturation boost), which can deteriorate it even further. The more processing your image goes through unnecessarily, the less versatility you’ll have to edit it without damaging your image. A RAW file will give you the photo in its unprocessed state, providing you with an ample amount of room to work with.
More Information = Higher Quality Processing
The main (and very important) benefit of capturing your images in RAW is an editing process that goes so much smoother. Since you’re working with more image detail and information, you can adjust your settings accurately and with less damage.
Adjusting your exposure is one of the best examples of how RAW can benefit your image during post process. Let’s see the difference between fixing your exposure in Photoshop as a RAW file and then converting it vs. adjusting the exposure as a JPG.
Here’s our example image (Figure 1). You can see that the sky is somewhat overexposed and needs to be dropped down in order to get more detail in the clouds, and also lessen the size of the sun.
Note: Click on images to see at full resolution.
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First, let’s adjust it as a RAW file. When I drop the Exposure slider down to -2, I end up with this result (Figure 2). As you can see, the overexposed clouds and sky apparent in Figure 1 have now been reduced so that you can see some great detail. The sun is also back down to its normal size rather than taking up a large portion of my image. If I were to continue editing this image, I would do some exposure blending to combine the nicely exposed sky we have now (Figure 2) with the foreground in Figure 1 as that is now a bit underexposed.
Now let’s see what happens in Photoshop when we adjust our image exposure as a JPG file instead of RAW. Like in Figure 2, I'll reduce my exposure by two full stops (Figure 3).
This image looks pretty horrible when compared to Figure 2. Adjusting the exposure as a JPG essentially just adds white or black to your image. Instead of correcting overexposed sections and recovering data, you now have a thin layer of black over the blown highlights. If it were up to me, I’d rather take the original image than a photo with an exposure fixed as a JPG.
With RAW, your photo will have additional information to work with, but not an unlimited amount. The limit of exposure correction is really only two full stops in either direction – that is, you can reduce the exposure by two stops or increase it. Anything more will produce an unnatural effect.
In the end, this limit will help you as a photographer since you shouldn’t really be over or underexposing an image by more than two full stops anyways. Otherwise, photographers would just be shooting whatever they want with no regard to the proper exposure triangle. Eventually, you’ll get to the point where you won’t even have to adjust your exposure at all, but it’s nice to have that safety net for important photos or tricky lighting.
The Drawbacks of RAW
There are a few notable drawbacks to RAW which make it impractical to certain photographers.
Larger Files – With more information in your RAW image as opposed to a JPG, the larger the file size will be. This also means that it will take longer to record your image to your memory card. If you’re a sports or action photographer who takes consecutive images frequently, your wait time is going to be much longer when working in RAW format.
Also, if you’re going to be taking many images, RAW files will cut down on your memory card space drastically. For example, if you’re going on an extended hike with no access to computers for a week, you’re going to run out of memory rather quickly. Of course, purchasing more cards is an easy fix to this, but it’s still something to consider.
Lack of memory space is not really a big issue as long as you have enough memory cards, so the main focus here is the drastic slowdown of continuous shooting mode and of course the wait time in between bursts. For those in fast-action situations, this can be a problem. Instead, you may have to focus on knowing how to adjust your settings on the fly to get the photograph you want. This will create less importance on editing versatility, allowing you to shoot in JPG without consequences later.
How the RAW file size affects image recording speed will also spill over into post process. If you do batch editing, expect your digital workflow to slow down drastically.
Lack of Processing – The benefit of RAW is that you have an image file that is unaltered, uncompressed, and otherwise unprocessed. The drawback of this is the exact same reason – since it hasn’t been processed, it’s unable to be printed or displayed until your photo has been converted. While this is usually not a problem for you personally since you'll likely have a RAW processor, it is an issue for those who do not. If you plan on shooting and sending your photos to clients or uploading them to the web immediately, this won’t be possible until you convert each image to JPG, TIFF, etc. Whether this is a problem or not for you depends entirely on your workflow: how many images you have and if you have time to edit and convert each and every photo.
For most photographers, it really pays off in image quality to shoot in RAW, especially those who spend a lot of time editing their images. However, if you rarely retouch your photographs, it's probably best not to clog up your storage space and slow down your camera by shooting in RAW format.
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