What are color spaces and why should you care?
Simply put, without getting into ICC profiles, they are models that translate the raw data into colors that can be displayed by your device (be it a monitor, cellphone or printer). The sensors of digital cameras actually record a big amount of data that includes colors that many devices can’t even see. In fact it records colors that the human eye is unable to see (such as infrared). There’s a couple of standards in use nowadays for print and web use: sRBG (the standard for office and home use, such as on the web), AdobeRGB and ProPhotoRGB.
Take a look at the following image. The horseshoe shape is the spectrum of colors that the human eye can see. The little triangle inside is sRGB, the colorspace that is by far the most used over the web.
It is the standard colorspace that all non-color managed applications use to display their interfaces. So what happens when you look at an image in a non-color managed application? The colors look washed out and what you envisioned on your computer is lost in (color)translation.
Now let’s look at AdobeRGB and ProPhotoRGB
One thing you might notice here it that ProPhoto can actually hold colors outside of the spectrum of the human eye.
8-bit vs 16 bit (or higher)?
What does it even mean? Well basically it’s the amount of data each color channel can hold per pixel. This means that more bits is more data (which also means bigger filesize) and as such more control. You will get better gradients between colors and more control when adjusting curves/levels.
So what does all of this mean for the average person? Working in 8-bit sRGB is definitely the most convenient, less likely to cause problems with correctly showing your images to others. But keep in mind that future proofing your work is never a bad thing. You might not be thinking about printing right now, but when you do it would be a shame if you had to redo everything from your RAW files (you do keep a backup right?) when you do.
Preparing your images for output
Ok so you decided to work in a colorspace other than sRGB, how do you make sure your images display correctly on other people’s devices? It’s actually not that difficult. In photoshop you simply “Edit -> Convert to Profile…” and select sRGB before you save your image for the web. Lightroom and other programs all have export options that allow you to convert to sRGB or already do it by default.