Focus stacking is a method of combining or blending several photographs to create a final photograph with more depth of field. Often used in macro photography, focus stacking in increasingly used for landscape photography.
Focus Stacking Guide
- What is focus stacking?
- Why is focus stacking needed?
- Equipment needed for focus stacking
- How to do focus stacking
What is focus stacking?
From Wikipedia: Focus stacking (also known as focal plane merging and z-stacking or focus blending) is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images.
Why is focus stacking needed?
Focus stacking is needed when the photographer wants to create a greater depth of field than the camera and lens will allow.
Camera lenses can only focus on a single plane of focus. Everything else closer or farther from the focus plane will be less focuses. The amount of perceived in focus area is known as depth of field.
Depth of field in influence by the type of camera, the type of lens, the closeness of the subject and the aperture used. Wide angle lens for example have greater depth of field then telephoto lenses. Macro lenses have a very short depth of field.
Using lenses wide open say with an aperture of 1.4 will have a shorter depth of field than an aperture of 32. Learn more about aperture here.
Often landscape photographers attempt to minimize the amount of areas perceived to be out of focus by using:
- Wide angle lenses
- Small apertures
- Focus at the hyperfocal distance
hy·per·fo·cal dis·tanceˌhīpərˌfōkəl ˈdistəns/noun
- the distance between a camera lens and the closest object that is in focus when the lens is focused at infinity.
The hyperfocal distance is about one third of the way into the scene. But objects closer than this distance may appear “soft” in focus.
Focus stacking attempts to eliminate these out of focus areas by combining three or more photographs – one focused on the foreground, one focused on the middle ground and one focused on the background.
Or in the case of say a macro or closeup photograph of a fly, one shot of the front feet, one of the eye and one of the wings.
Equipment needed for focus stacking
To create the individual images needed for a focus stack you will need to create several images in which only the focus point changes. This requires a rock steady tripod, a cable release and then Adobe Lightroom/Adobe Photoshop to combine the images. You don’t want any movement between photographs.
Workflow for Focus Stacking in Adobe Lightroom and Adobe Photoshop
Quick Method of Focus Stacking
- Capture a series of images – each focused on a different point.
- Load into Lightroom, edit and sync.
- Open all the images as layers in Photoshop.
- Make sure all three layers are highlighted then Edit->Auto Align Layers and select Auto.
- Select Edit->Auto Blend Layers and choose Stack Images.