I did a test with a Sony A7s full-frame mirrorless cameras along with the wonderful Sony Zeiss 55mm f/1.8 lens. This awesome low light camera paired with this incredibly sharp lens made for a fun test in which I show you what the same scene looks like at various apertures.
For this test, I placed the small bust of King Tut and four aquatic figurines on a green cutting mat. With the camera locked down on a tripod to ensure nothing moved from shot-to-shot, I used a remote to trip the shutter and avoid any movement whatsoever.
The following photos were shot a full stop apart from each other:
f/2 – f/2.8 – f/4 – f/5.6 – f/8 – f/11 – f/16 – f/22
Moving from wide open (f/2) to stopped down (f/22), we were cutting in half the amount of light hitting the sensor with each stop.
Distances to the camera and our main subject (King Tut) are at the very bottom of this post.
All photos were shot at ISO 400 and of course at 55mm as it’s a prime lens.
You may click a photo to see it much larger (2000 pixels wide) in a new window.
As you can see, being just 22″ (55.8 cm) from my subject, depth-0f-field is razor thin. Even with the Sony A7s’ focus peaking feature, I was working with millimeters.
Even at f/22, not everything is in sharp focus. This is due to working in close. If you think this is bad, shoot tiny objects with macro lenses and depth-of-field shrinks even more!
Coming up, we’ll have examples of various apertures, but where our subject it quite a bit away from the camera. In those you’ll see how at a given aperture (f-stop), you gain quite a bit more depth-of-field compared to this example where we’re close to our subject.
In this example with King Tut, I wanted to demonstrate that at f/2 with the blue/green seahorse just 6″ (15.24 cm) forward, you can throw it quite a bit out of focus. The dolphin is the same distance away, only behind Tut. If it were twice the distance (the position of the orangish seahorse, well, you can see what happens to it. Not imagine if it was four times the distance, eight times the distance and so on.
Working in this close to your subject and with a maximum aperture such as f/2, what’s going to be in focus is minimal and the further away something is from the subject…even if just 12″ (30.48 cm) away, it gets harder and harder to determine what’s in the background. Thus, further isolating your subject and placing the focus squarely on them. Tut likes that kind of attention. He’s a king after all.
Distances:
Cutting mat and yardstick were pushed flush to the wall.
Tut’s eyes were lined up at the 17″(43.18 cm) mark of yardstick.
Distance from Tut’s eyes to the image sensor was 22″(55.8 cm) .
Distance from the wall to the image sensor was 39 1/8″(99.38 cm) .
Blue/green seahorse on the left was 6″(15.24 cm) in front of Tut.
Dolphin was 6″(15.24 cm) behind Tut.
Small seahorse at back left was 12″(30.48 cm) behind Tut.
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