Focus stacking allows you to increase the depth-of-field in a scene.
You photograph the subject repeatedly.
Each photograph is focused at a different point on the subject.
Then, the photographs are merged, stacked, into a composite photograph.
The composite photograph contains the in-focus parts of the photographs.
Let's review depth-of-field.
Let's say you focus on a ruler at the six inch mark.
That's where the photograph will be sharp—at the six inch mark.
However, there's an area in front of—and behind—this sharp point—that looks sharp to our eyes.
This depth-of-field area is changed by two factors:
1) Lens opening (aperture, f/stop)
2) Distance from the subject.
If you set the lens opening to f/4, the depth-of-field area will be shallow.
If you set the lens opening to f/16, the depth-of-field area will be larger.
If everything in the frame is more than about twenty feet away, everything will appear to be sharp.
The depth-of-field area is huge.
As you move the camera closer to the subject, the depth-of-field area decreases dramatically.
Download one or more of the programs below.
They're free or they offer free trials.
PhotoAcute Make sure your camera model is supported.
TuFuse Free, but uses the command line (for the computer savvy only)
TuFuse Pro Has a more user friendly interface
The two programs above don't align photographs.
Zerene Stacker Windows & Mac
Some of the above programs also offer:
• Noise reduction.
• Retouching tools.
The camera can't move.
Use a tripod.
Photograph non-moving subjects.
Photograph using low contrast light, such as window light (no sun), in the shade, or on an overcast day.
If you're outdoors, the light should remain constant.
If the light is changing, you'll have to edit the photographs to make the lighting consistent.
The photographs must be identical, except for the focus.
Therefore, use manual camera settings.
Set the lens to manual focus.
There's a switch on or near the lens.
Set the exposure manually.
If you were to use P, A/Av, or S/Tv, the brightness of the photographs would vary.
Set the white balance to the appropriate setting for the scene.
If you were to use auto white balance, the color may vary from photograph to photograph.
Set the ISO manually to a setting appropriate for the scene.
While it's unlikely, your camera could change the ISO when taking the photographs.
Leave some extra space on all four edges of the frame.
This allows for later cropping.
The final image will be distorted near the edges because of a slight perspectives change in each photograph.
Plain backgrounds work better.
• Similar colors.
• Similar tones, i.e., no bright and dark areas.
If the background in the composite photograph is poor, you may have to insert the background from one of the photograph.
Photograph the pocket watch from "nose to tail," shifting the focus slightly for each shot.
Your first photograph should be focused slightly in front of the watch.
The last photograph should be focused slightly behind the watch.
Take many photographs.
Use a remote shutter release to avoid moving the camera.
Focus gently so the camera doesn't move.
If you'll be doing lots of focus stacking, consider getting a camera rail.
Instead of focusing by turning the lens, you'll move the camera forward on a rail.
Use the above software to stack the photographs together.
Crop the edges, as needed.
In the photograph below on the left, the banana was photographed thirteen times at f/4.
The focus was changed thirteen times.
The photographs were stacked with Zerene Stacker using Stack > Align & Stack All (DMap).
The entire banana is in focus, and the busy background is blurred.
In the photograph on the right, the banana was photographed once.
The lens was focused at the midpoint of the banana.
The lens opening was f/16.
Despite the small lens opening, the entire banana isn't in focus.
The busy background is sharper, making it more distracting.
|Focus Stacked||Single Photograph at f/16|
|Enlarge Both Photographs|
The focused-stacked photograph needs some editing to restore exposure, contrast, and color.
Photographic Multishot Techniques by Juergen Gulbins and Rainer Gulbins