HOW TO | focus stack images
1 Set up your scene
First set up and take your photos. We’ve arranged some chillies on the lid of a MacBook Air, and propped up a white envelope in the background to form a backdrop. We’re shooting outside, partly to make use of the sunlight. If you’re indoors, you might need to use a flash.
2 Take the photos
Once your camera is focused on the back of the composition, take a shot, then gradually bring the focus closer, taking a shot every time the area in focus changes. A tripod or other support is essential, since any movement between the frames makes it impossible to stack them.
Open your photos in Elements. Pick the one with the focused areas furthest back for the background, then paste images in as new layers, letting the focused area come forward, so the top layer has the front in focus. Save as a PSD file. Click the eye icons in Layers so only the bottom two show.
4 Layer mask
The layer mask is essentially a hole that allows the layer below to show through. Select Layer 1, and click the rectangle/circle icon. A white rectangle with a cyan border appears. Clicking the picture thumbnail moves the border across, and your edits affect the image itself.
Select the Brush tool and make your foreground colour black. Use the eye icon to compare images, then paint over areas that are sharp on the lower layer but out of focus on Layer 1. If you paint over a bit you don’t need, swap your colours to paint in white, and go over it again.
6 More layers
Unhide Layer 2 and repeat the process. This can take time if the images aren’t aligned to take into account the change in view caused by focusing. A little depth of field isn’t such a bad thing, and the tip of the green chilli on the left has changed position a lot as we’ve refocused the lens.
7 Even more layers
Do the same with layers 3 and 4. As you move up the layers, the work it takes to mask off unsharp areas should decrease. Popping layers in and out of visibility, and disabling layer masks, allow you to see areas that could be sharper, and work out which layer should be showing through.
8 Flatten and export
Once you’re happy with your creation, save the PSD file one last time, then select Flatten image from the Layer menu. You can then use Save As from the File menu to export your image as a TIFF or JPEG. Keep the PSD for reference, or for touching up again at a later date.