Focus Stacking in Photoshop
The Canon R series of mirrorless cameras, as well as various bodies from other manufacturers, feature focus stacking, which is the ability to take and then combine multiple frames of a scene and create a much greater depth of field than that which can be obtained by simply shooting with a smaller aperture. Although this is not new, and can be performed manually on any camera, many newer cameras offer the ability to take the multiple shots while changing the focus in incremental steps. The tricky part is the combining of the multiple images into one image with the different focus points combined. Here I will present the method I use with Photoshop.
The image I chose for this was a watch placed about six inches in front of the camera. I used a Canon EF 50mm/f1.8 lens (nifty fifty) and a 20mm extension tube so I could focus close enough to fill the frame. The exposure settings are irrelevant but for the sake of the impressive image quality of the Canon R6 and the built in image stabilization, I was shooting at ISO 3200 handheld at 1/100.
The process can be broken down into two steps: 1) the shooting with the focus automatic focus adjustments and 2) the combining of the multiple images into one.
For the Canon bodies, the first step in preparing to take the shots is to enable the focus bracketing.
Go to the 5th page of the red camera feature menu and select Focus bracketing and enable it.
The Focus bracketing set up menu is not so straight forward since the values are all relative and not absolute. You guess the maximum number of exposures and select the Focus increment (smaller is better quality but more frames). I enable Exposure smoothing to keep the exposures constant across the sequence. The camera is now set up to take as many frames as are needed (up to the max you specify) in order to cover the scene.
Start by focusing at some point at the near field of the subject.
One push of the shutter button starts the sequence. It's entertaining to watch the focus ring on your lens as the camera quickly goes through the frames and the lens moves throughout the process. When it's complete, you have a series of individual frames but taken at different focus settings. In the case of macro photography, it is very likely that none of the individual images are useful. Make sure you disable the feature when you are finished because it remains enabled until you either disable it or turn off the camera.
At this point, I edit the images in batch like i would for any individual one, including noise reduction and sharpening.
Begin the process of combining the individual frames by opening them into a stack in Photoshop.
Click on File- Scripts-Load Files into Stack.
In the dialogue, click to align the source images.
Once they are all loaded, you will see individual layers. Now select all of the layers.
Now click on Edit-Auto-Blend Layers.
In the dialogue, make sure to select Stack Images and check Seamless Tones and Colors and click OK. The images will become layer masks and all you have to do it flatten the image which leaves you with the resultant image with all the frames combined.
Just treat the image like an other and you are done. This example was the result of 34 individual frames. Since this was a moving subject (the second hand) you can see that it took about three seconds to capture the images.
Be sure to check out my other blog articles for useful photographic tips and techniques.
Comments
One question... I'm not a seasoned PS user (but LR big time), Is that step you have for "Load Files into Stack" something PS has OOTB? Or is that some "script" you had to do on your own or get elsewhere.