The viewfinder (whether it’s optical, an LCD screen or live-view on your computer) isn’t merely a technology tool; it’s also the way you see the world when you’re composing photographs. Through it, your eyes are grafted directly to your camera so that you can actively take control of your image making.

Although the viewfinder has plenty of information built into it—such as the shot count, exposure settings, various warnings, focus indicators and your light meter—it is, at its heart, a cropping tool that can edit the world into a two-dimensional photograph. It’s the link between you and your camera.

In a way, everything else, including lens effects, raw image data, color balance, etc., connects ...

Get Camera & Craft: Learning the Technical Art of Digital Photography now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.