Once a teacher, always a teacher. I guess that’s the reason I like to create and share blog posts that relate to things I’ve learned about photography. Such as depth of field.
Depth of field, more specifically shallow depth of field, is the reason many macro photographers like to do focus bracketing and focus stacking.
In order to demonstrate shallow depth of field, I arranged the same three studio “models” (used in my last blog post) in a way that would be impossible for the camera to capture all three subjects in focus. For what it’s worth, the distance between the closest and farthest model was approximately six inches.
To add to the challenge, I changed the aperture from f/7.1 to f/5.6 — that’s closer to the “sweet spot” of f/4 for the lens in my Panasonic Lumix DMC-FZ300, but the depth of field at f/5.6 is shallower than f/7.1. How shallow is it? (Queue Johnny Carson.) For the answer, I turned to my favorite online “Depth of Field Calculator.”
Notice I selected “Panasonic Lumix DMC-FZ150” as the camera. That’s because the FZ300 isn’t on the long list of cameras supported by the calculator. No problem. I own both the FZ150 and FZ300 and I can tell you they are virtually identical in every significant way.
My camera was mounted on a tripod so that the front of the lens was approximately five inches from the closest subject. The focal length (mm) of the lens was derived from the EXIF info for one of the three photos shown below.
Look at the calculator output, highlighted by the red rectangle in the preceding screen capture. Notice the total depth of field is 0.24 inches — that’s only around 1/4 inch! There’s NO WAY all three subjects can be acceptably in focus using my FZ300 and the camera settings I selected.
Post Focus
I used Panasonic “Post Focus” to capture the scene. This time, I used “Post Focus” to select different focus points after the shot was taken. During playback, I selected three focus points, one at a time, and saved the following JPG files.
For the first photo, I selected a focus point on the toy monkey. Notice the orange dinosaur in the background is clearly out of focus. Wait, did I really just say that? Yeah, go with it — you know what I mean.
Focus point on nearest subject.
For the next photo, I selected a focus point on the green dinosaur. I don’t know whether I’d call the other two subjects “acceptably in focus” but I know they aren’t tack sharp.
Focus point on middle subject.
For the last photo, I selected a focus point on the orange dinosaur. Notice the toy monkey in the foreground is out of focus.
Focus point on farthest subject.
So there it is — if you would like all three subjects to be in focus then focus bracketing / focus stacking is the only way to go.
My last blog post, entitled “Focus bracketing using Panasonic “Post Focus,” explains how Panasonic “Post Focus” can be used with Adobe Photoshop to do focus bracketing and focus stacking.
Related Resources
- How to use the Post Focus / Focus Stacking feature. [An article from Panasonic.]
- Experience 4K Post Focus in Panasonic LUMIX Cameras – Presented by LUMIX Luminary Photo Joseph, by Panasonic North America (4:33)
- Panasonic FZ80/82 Digital Zoom, 4K Post Focus and Manual Focus, by Graham Houghton (15:16) [The segment related to “Post Focus” begins at ~8:22.]
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