What is Raw format?
The RAW file format is digital photography’s equivalent of a negative in film photography: it contains untouched, “raw” pixel information straight from the digital camera’s sensor. The RAW file format has yet to undergo demosaicing, and so it contains just one red, green, or blue value at each pixel location. Digital cameras normally “develop” this RAW file by converting it into a full color JPEG or TIFF image file, and then store the converted file in your memory card. Digital cameras have to make several interpretive decisions when they develop a RAW file, and so the RAW file format offers you more control over how the final JPEG or TIFF image is generated. This section aims to illustrate the technical advantages of RAW files, and makes suggestions about when to use the RAW file format.
RAW Image Formats:
.arw .srf .sr2 (Sony)
.crw .cr2 (Canon)
.cap .iiq .eip (Phase_One)
.dcs .dcr .drf .k25 .kdc (Kodak)
.nef .nrw (Nikon)
.pef .ptx (Pentax)
.raw .rw2 (Panasonic)
.raw .rwl .dng (Leica)
1. Get the Highest Level of Quality
This is one of the biggest benefits. When you shoot in RAW you record all of the data from the sensor. This gives the highest quality files. And when it comes to your awesome images, you want high quality.
Look at it this way: all cameras technically shoot RAW. Yes, it’s true.
The difference when you shoot in JPEG format is that the camera does it’s own processing to convert the RAW information into a JPEG.
However, your camera is nowhere near as smart as your brain, nor is it as powerful as your computer. When you shoot RAW, you’re able to do that processing yourself. You can make the decisions on how the image should look, and produce way better results.
2. To be able to fix White Balance
The camera Auto-WB setting is good but it is never perfect and for some scenes it can go badly wrong. It’s very hard to get a perfect WB in the camera but it’s easy to do it in post-processing. And you can try several different color temperatures and find something you didn’t consider in the shoot. To correct the WB without destroying information you need to shoot RAW.
3. Record Greater Levels of Brightness
Levels of brightness are the number of steps from black to white in an image. The more you have, the smoother the transitions of tones. Smooth is good. JPEG records 256 levels of brightness, and RAW records between 4,096 to 16,384 levels! This is described with the term “bit”. JPEG captures in 8bit, and RAW is either 12bit or 14bit. That’s what that bit business means!
The effect this has on your images is huge. Those additional steps of brightness let you make more adjustments (exposure, blacks, fill light, recovery, contrast, brightness) to your image without a significant reduction of quality, because there’s more levels to work with!
It’s also easier to avoid or correct posterization in your images when you shoot in RAW. Posterization is the banding that you often see in bright skies, which really doesn’t look good in prints!
4. Easily Correct Dramatically Over/Under Exposed Images
Obviously you want to get the best exposure in camera, but sometimes things move fast (especially with weddings!) and you wind up with a dramatically over or under exposed image.With RAW you have additional information in the file, so it’s much easier to correct the image without a drastic reduction in quality. You can also recover more blown highlights and clipped shadows.
5. Get Better Detail
When you shoot RAW you have access to sharpening and noise algorithms in a program like Lightroom that are way more powerful than those found in your camera.
Plus, these sharpening and noise algorithms are always improving, so in the future you’ll be able to re-visit your RAW files and take advantage of these improvements.
6. Enjoy Non-Destructive Editing
When you make adjustments to a RAW file, you’re not actually doing anything to the original data. What you’re doing is creating a set of instructions for how the JPEG or TIFF (another file format) version should be saved. The awesomeness of this is that you never ever have to worry about ruining an image, accidentally saving over, or being unable to go back and make changes. You can always reset your adjustments, and start over again.
JPEG files lose quality every time you open them, make adjustments, and save again. So if you’re making edits to JPEGs you always have to be duplicating the image and saving out a new version if you don’t want to lose file quality.