Focus stacking is a technique that allows you to achieve a deep depth of field in a final image by blending (or stacking, as it’s often referred to) several images together. The idea is that you take several shots of your subject, each focused on a different spot. Once you combine the images together in Photoshop, you’ll end up with a perfectly sharp, in-focus subject.

You’ve spent countless hours planning and obsessively checking the weather to go out and capture what you hope will be an epic Milky Way shot. You’ve got a great location, a killer composition, and took the time to carefully dial in your focus and camera settings. You get them home and realize that there is just too much noise for there to be a good image. What went wrong? How do people get these epic, low-noise Milky Way shots?