RAW versus JPEG
So – what’s the big deal? What’s a RAW file, and is it really better than a JPEG? How does processing a RAW file compare to developing an image in a darkroom? Am I a “real” photographer if I process my images in Photoshop?
These are questions I hear all the time – one fan even told me he and his wife were “on the cusp of sleeping in different bedrooms” and “sharing parts of the dog” because they couldn’t agree on the best file format!
So, let's start by looking at this analytically. (Bear with me here – it’s not so bad!)
What is the difference between a JPG and a RAW file? In order to create a raw file, the following steps take place in your camera:
- Photons reach the pixels on the sensor
- An electrical charge is created on each pixel
- The charge is converted to voltage
- The voltage is amplified
- The Analog to Digital Converter (ADC) measures the volts and assigns discrete values
- The ADC converts this information into binary
That's it. That's a RAW file. (Still with me?)
But let’s say you are shooting JPG instead. In this case, the camera continues to process the data it has collected…
- Color information is created using “Bayer Interpolation”
This is where things start to get a little twitchy. The problem is, your camera can't see... it’s completely blind. So it uses a mathematical equation to make a guess at the appropriate colors for your photograph. Sometimes it is even correct. The algorithms are getting better as technology improves, but the fact is, the camera doesn’t always get it right, and it is easily confused.
- White balance adjustments are made
Did I mention that the camera is blind? It uses a complicated mathematical equation to guess at a neutral tone. Sometimes it’s right – and sometimes it’s painfully wrong! (Have you ever taken a photo indoors and ended up with an oddly yellowish or bluish print?)
- Contrast enhancements and other adjustments are made
The camera is making a series of tonal adjustments. The same tonal adjustments you’d make for yourself in the RAW converter if you chose to shoot RAW. If you shoot JPEG, those adjustments are automatically made for you… by your blind camera!
- Sharpens the image
You guessed it - another algorithm... sharpening is applied indiscriminately across the entire image. Whether it needs it or not.
- And last... but certainly not least. The camera compresses the data.
That means it throws away any data it didn't use in order to shrink your final file size. If it guessed wrong about the correct color balance - that's too bad. The correct data has been thrown out. If the contrast is too high, or the sharpening is too extreme... you are out of luck. The data is gone and it cannot be recovered. Ever.
If you shoot RAW, those last five steps are up to you. Luckily, you aren't blind. (At least, I’m assuming you aren't.) You know how the scene looked in reality. So, rather than relying on a series of blind mathematical equations, you can rely on your own vision. Is it perfect? Will you get it right every time? Nope. But it's a whole heck of a lot more reliable than the camera.
How does processing a RAW file compare to developing an image in a darkroom? Well - Photoshop (or whatever software you use) is your digital darkroom. You use it the way a film photographer would use a darkroom... to brighten or darken the photo, to adjust contrast and luminosity in specific areas of the image, to adjust color, and so on. Developing an image in a darkroom is completely different from processing an image in Photoshop... but it accomplishes the same purpose. Would you say that a photographer who shoots film and develops his own film in the darkroom isn't a photographer? And would you say that a film photographer who takes his film from the camera and sends it off to have the developing and printing done by someone else is superior to the one who does it himself?
It's a strange argument, really. In the past, a photographer who didn't do his own darkroom development was considered "less than"- not a "real" photographer. But now, with the advent of digital photography and Photoshop, the photographer who actually goes beyond the release of the shutter to handle the processing of the image himself is in question.
In the end, I find myself asking - does it really matter? It's art. Photoshop is a tool. Just as a brush is a tool for a painter, and the kiln is a tool for a potter. So in the end, does it really matter? I’d rather just enjoy photography for what it is. Art and pleasure. An expression of what you love and who you are.
Love it. Don't fight it.