Here’s a simple lesson by Dylan Bennett on what depth of field is, how it works, and how to control it in your photography.
Like in the “ISO” clip, good analogies to to help remembering what to do to achieve desired results, but keep in mind this is not exactly how the physics behind it works.
A fourth factor, often ignored, is that hi-res produces a deeper DOF, and cutting resolution will help with shallow DOF where other controls are difficult.
for dof, are distance, focal length, and aperture additive?
Also not discussed here is Depth Of Focus, the size of the sensor/film size/image acquisition target of choice behind the lens. It affects depth of field and focus acuity as well.
A 50mm lens at an f/4 focused at 6 feet on a 4×5 film camera (or one with a digital back) has substantially shallower depth of field than a 50mm lens at f/4 focused at 6 feet on a 35mm (or full frame DSLR) camera. So too the difference between 1.5x, 1.6x and full frame cameras.
The takeaway point being this – the size of the image behind the glass needs to be considered and calculated for. There are circles of confusion and depth of field charts for this. If you shoot older lens, there are often depth of field markings on the lens barrel. When pulling focus shooting video on DSLR cameras, there is a world of difference between working with an APS-C size sensor and a full frame sensor. And no photographer I’ve met in my 20 years in the biz uses the term “wide” to describe depth of field. “Deep” or “Shallow” are the preferred terms.
he may be talking about sensor size?
(late reply, but still)
No, he is not talking about sensor size, but about image resolution. The video above already mentioned that depth of field is what we perceive as in focus.
For example: If you would take a magnifying glass to look at a picture that is completely out of focus it looks terrible, but if you take a few steps back it doesn’t look that bad. It works the same with image resolution, if you scale down a picture to a lower resolution it looks more in focus. Also, the transistion from in focus to out of focus is smooth. This means that in this transition, more looks in focus, increasing the DOF.