Yes, but we are all making assumptions about subject matter here. I'm thinking about my usual people photography at 1 to 8 metres and you are thinking landscapes at infinity. Both are valid, but both are assumptions about the subject intent.
Ergo, none of us can really generalise unless the question/answer is genre specific.
Oh, I see what you mean. Not really. I think you would end up being diffraction-limited at standard-to-long focal lengths. At Ultra-Wide, the aperture can be a similar size to the area covered by a pixel for quite nearby objects.
A not useful rule of thumb: focus one-third of the way into the scene. It is almost never true.
One big advantage you have is that people are all more-or-less the same size.
If you had a 30m tall giant, with a 20m tall wife and 10m child turn up on your doorstep, followed by a 20cm high family of Borrowers, all asking for portraits - because they like your work on regular humans, you might have to do a bit of head-scratching. :-)
For such occasions a fourth Hail Mary then wing it 😂
Hi,
I get by with them. :) Note that the photo part of this is pretty small. Hence using a 16MP camera. And the old school lenses I've had since I had an F2.
Now my other use for this printer are the lighthouse quilt blocks. These are done with a Pentax 645D. 40 MP because I'm printing larger. But I don't use the DoF scales here. I shoot four shots one right after the other at f5.6, f8, f11 and f16. Then I pick the one I wish to go with. Usually f8 or f11.
And then I also print on paper at 16x20". Usually the same aperture shot I picked for the DTG printer.
Stan
Like most of photography once you get past a certain stage, you have to have an idea about what you're trying to achieve.
This seem a reasonably summary about the way dof changes from infinitely greater behind the point of focus at hyperfocal distance focus to close to equal by about 1/10th HD.
Whether easily applied in the field perhaps depends on whether a photographer is aged over 50 - when you often "worked it out in your head" - provided he/she is also good enough at logic to complete the mental arithmetic.
Plus 1.
Some very experienced photographers have commented that they don't need any rules as their experience tells them what works and what doesn't.
I totally agree and that's why I put these rules in the "Beginners' Questions" forum. The rules are aimed at less experienced photographers who would like to understand a little more about the maths of DoF.
If they are too difficult to understand then don't worry: simple trial and error can always be used instead. To be honest, I use trial and error (and my experience) most of the time and only occasionally work out the DoF.
However, for those who are interested and who are comfortable with the mathematics, the three rules in my OP can help when you are thinking about depth of field and the camera settings required to get the shots you want.
That's a question of learning style. I've always found that whilst I can learn by trial and error, knowing how things work speeds up the process considerably.
The rules of thumb are helpful but I find the DOF app on my phone quick and easy to use if I need confirmation that my aperture is OK.
I once wrote a program to optimize focus distances and f-stops for landscapes. It proved that my experience had taught me a few things that were wrong.
blog.kasson.com/the-last-word/choosing-f-stops-and-focus-distance-for-landscapes/
blog.kasson.com/the-last-word/optimizing-f-stops-and-focus-distance-for-landscapes/
blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-an-example/
blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-another-example/
blog.kasson.com/nikon-z6-7/ff-examples-of-optimal-blur-management/
Which approach do you use for focusing?
For those interested in getting to the bottom of DoF calculation I can advise them to read up on the excellent explanation by Mike Davis on DPReview. He needed three posts for a complete write down, so this is rather intense. It's just about what I learned on the academy and then forgot later in my career ;-)
If there's no foreground - like shooting off a cliff, or a peak, or a tall building, then shoot at the lens best f/number, and focus on the main interest - which is likely in the hyperfocal-infinity range.
If there's something important in the foreground, focus on that, and stop down for distant stuff.
Which is sub-optimal, but in the second case, I'm almost always shooting fairly wide, so my "foreground" is "hyperfocal" - or close - already, and I figure I'm not missing out so much.
I hadn't seen JIm K's notes on f-stops and focus distance before this thread. I need to think more about that.
The interesting question is where to focus if you want "infinity"/far-objects and as much of the foreground to be sharp and/or what CoC to use for hyperfocal when you do not know in advance what kind of output and viewing distance you should count on.
I am also working through Jim's post, looking for more insights into the topic.
To be safe-ish, twice the pixel pitch. To be safe, the pixel pitch. To be really, really safe, half the pixel pitch. You probably won't like how little DOF there is with any of those.
