Why don't EOS DSLR's have a built-in DOF calculator?

I downloaded a depth of field calculator app for my Android phone and got to thinking... why don't EOS DSLR's have a DOF calculator already built-in? Many of the Canon lenses report subject distance information for calculating proper flash exposures, so why can't this be used to calculate DOF given the focal length and aperture?

Assuming that in the future all lenses will report subject distance information to the camera body, it would seem easier for an average user to select the depth of field they want and have the camera calculate the appropriate aperture required.

Because they have a depth of field button?

shaftmaster wrote in post #12316342
I downloaded a depth of field calculator app for my Android phone and got to thinking... why don't EOS DSLR's have a DOF calculator already built-in? Many of the Canon lenses report subject distance information for calculating proper flash exposures, so why can't this be used to calculate DOF given the focal length and aperture?

Assuming that in the future all lenses will report subject distance information to the camera body, it would seem easier for an average user to select the depth of field they want and have the camera calculate the appropriate aperture required.

Some Canon cameras have a mode called A-Dep, you focus on the near and far subject material, and it will set up your aperture for you. I think other versions of this A-Dep would just try using all AF points and it would set an aperture that put the most boxes in focus.

well, they have the "A-DEF" mode so thats a similar capability to what you mention. They just don't any way to display the info numerically though. It would be kinda nice to have

If you have enough time to do calculations on your camera, you have enough time to retake the shot if the DOF is insufficient

smorter wrote in post #12316561
If you have enough time to do calculations on your camera, you have enough time to retake the shot if the DOF is insufficient

+1

A lot easier to hold a button and scroll then to use a calculator on a camera without number buttons. And plusss, just another added feature to run up cost that most of use wont use.

Just what we need, another feature we won't use. Add that to creative filters and print and ...

Not needed - DOF is something which comes instinctively through practise at using a camera to take pictures. It's a pity that so many camera buyers - notice I'm not saying photographers - want everything automated.

David

I think that idea would be quite cool *shrug*...

Just have a number in the viewfinder that changes with focus distance and aperture to calculate the DOF... It would show up in feet, inches or meters depending on custom function choice. I think that would be quite cool to be honest, and not really intrusive if it is just implemented like the other options in the viewfinder. And can be disabled for those who are offended by it!

Why no DOF Calculator? Perhaps because Canon though it might be good to leave something for the photographer to do?

Yes, some cameras have A-DEP (or a variation of it). I think it tends to be a little conservative, using a smaller aperture than really necessary. But, it's been many years since I've tried it, so maybe it's changed.

Invertalon wrote in post #12317464
I think that idea would be quite cool *shrug*...

Just have a number in the viewfinder that changes with focus distance and aperture to calculate the DOF... It would show up in feet, inches or meters depending on custom function choice. I think that would be quite cool to be honest, and not really intrusive if it is just implemented like the other options in the viewfinder. And can be disabled for those who are offended by it!

That was my thought too, tell me what my DOF is so at least I know whether to stop down to get more of my subject in focus.

Brendo666 wrote in post #12316579
A lot easier to hold a button and scroll then to use a calculator on a camera without number buttons. And plusss, just another added feature to run up cost that most of use wont use.

I think you missed my point. There is no need to have number buttons, since the camera already knows the focal length, aperture, and subject distance.

I seriously doubt this would add cost to the camera, and if it sold more cameras then it might even lower the cost.

Botom line... they could do it easily. Give it 5 years and it will be so.

Year 1 - nobody does it
Year 2- Pentax does it
Year 3- Samsung does it Poorly
Year 4- Nikon does it just a bit better than Pentax
Year 5 - Canon does it just about as good as Pentax

It would very usefull in close-up work like food and product photography. Back in the dark ages, lenses had scales that gave this info. I do a fair amount of scale work and this would be great.

I think it's a phenomenal idea! They could even do it with a firmware update!!!