Updated: Sep 11
Depth of field is the distance near to far of that which is in focus when taking photographs. For example, a portrait often has a shallow or small depth of field so that the most detail is in the person being photographed while the background is blurry and seemingly less important. Conversely, a landscape photo will likely have most things from the foreground, midground, and even some background in focus. Learning how to achieve these, as mentioned in another recent post, involves practice with the aperture setting on the camera. To my limited knowledge, this is the biggest factor affecting depth of field when shooting with 35mm film cameras.
When I first started shooting film as a photographer, I had two cameras - the Pentax K1000 with a 50mm f1.8 lens, and an Olympus pen EES-2 half-frame camera. If you're just starting, I suggest an SLR camera like the Olympus Om1 with a nice 50mm f1.8 lens. The reason being is that you can see through the viewfinder what will be in focus and by pressing a small button on the lens, you can get a depth of field preview. There is often also a scale on the lens where you can see how many feet or meters will be in focus at a given setting. For example at f5.6 aperture, 3 feet in front to 3 feet behind your subject will be in focus, but everything closer than the 6ft bubble of focus will be blurry. At f16, everything in the frame from 1.5 feet to near infinity will be in focus. This may vary by the lens, so you'll need to look at your lens and see the scale which usually reads 16-8-4-_-4-8-16 and has a line corresponding to focus distance labels on the focus ring.
Once I had practiced this and saw the results, I could better use what are cold zone focus or rangefinder cameras because, unlike a mirrored SLR camera, these other cameras have a window to show the approximate area that will be in the photo but no way to see what is coming through the lens. I won't go into details about the varying types of zone focus and rangefinder cameras with full explanation, you can read this article for more details about zone focusing: https://casualphotophile.com/2019/03/20/how-to-zone-focus-scale-focus/.
So how do I know what the photo will look like if I'm just looking through a tiny window that frames the shot? I infer from experience and knowledge of depth of field in relation to aperture (also called F stop) settings. For a portrait, I want shallow depth, so a lower f-number is better like 1.8, 2.8, or 3.5. For a scene or landscape, f8-f22 usually is best. Why is this useful when I can just use an SLR camera? One major reason for me is that I can now carry a much lighter, smaller camera. An SLR is much bigger and heavier than many zone focus or rangefinder cameras. If it's a hassle to carry a camera, I will shoot less and miss important street shots, family & vacation photos, etc. Learning depth of field with an SLR gave me the ability to imagine my shots at various F stops without needing to see it and thus carry some of the world's smallest cameras such as my beloved Rollei 35 which I wrote and ode to in the blog post here https://www.loftvisual.com/post/rollei-35-a-love-story. This tiny camera takes some of the best photos, fits in my pocket, and has endured since the 1960's. Mine is probably a decade older than I am and works very well.
As you can see in the picture above right, much more is in focus which is useful when using a zone focus camera. I love the small compact cameras with great lenses and the SLR's which I also have. I use the SLR to slow down, take pictures of specific things where focal precision is necessary or shoot landscapes that may require subject isolation such as an object or environmental portrait. The fact is we can control depth of field with the camera settings (if available), but my opinion is we should think about it and take our shots with intent.
What are your thoughts on depth of field? Does it matter when taking photos? Also, what is your favorite camera? Let me know in the comments and until next time, happy shooting.