DOF on digital cameras

[job]

DOF ( depth of field) is an optical illusion of the circle of least confusion of an out of focus area that still appear "sharp".
All along I find it ( DOF scale) on the manual lens working extremely well on films.
However, with nowadays increasing pixel sensors and the tendency to pixel count by magnification, I start to find the DOF concept and scale may not work properly on today digital cameras.
What is your experience ?

 

[Roger Hicks]

Far too many people look for more precision in photography than exists. There's a whole piece about DoF at http://rogerandfrances.eu/photography/dof where I discuss the variables involved, including camera shake (which is often ignores in such discussions), with examples.

Cheers,

R.

 

[grouchos_tash]

When I use cheaper old cameras I almost feel a sense of relief that the expectations are low. I am much more critical of digital photos because I expect them (wrongly) to look exactly like the scene I photographed (even though that isn't even very appealing).

 

[radi(c)al_cam]

What is your experience ?

Wait, do these digital wonder-thingies not have automatic depth-of-field indicator pointers?

Uhm — that was all mechanical, they can't do that anymore, I guess … 😛

 

[newst]

Wait, do these digital wonder-thingies not have automatic depth-of-field indicator pointers?

Uhm — that was all mechanical, they can't do that anymore, I guess … 😛

I guess that depends on the camera. Using Live View on my Sony I can see the actual depth of view image in the viewfinder before I capture the image.

 

[Godfrey]

DOF ( depth of field) is an optical illusion of the circle of least confusion of an out of focus area that still appear "sharp".
All along I find it ( DOF scale) on the manual lens working extremely well on films.
However, with nowadays increasing pixel sensors and the tendency to pixel count by magnification, I start to find the DOF concept and scale may not work properly on today digital cameras.
What is your experience ?

As Roger says, "far too many people look for precision where none exists these days."

DoF with digital cameras works just fine to a first order approximation. Open up the lens, focus zone shrinks. Close down the lens, focus zone expands. How closely it follows the markings on the lens, if any, is not really important because the markings were always just approximations anyway. Just like the DoF indicators on some cameras (I'm thinking older Hasselblad lenses) are.

G

 

[radi(c)al_cam]

Just like the DoF indicators on some cameras (I'm thinking older Hasselblad lenses) are.

G

Yes, but already some 60 years ago, certain Schneider, Voigtländer etc. lenses for 35mm (!) film cameras did have these «automatic» red pointers 🙂

 

[shawn]

" they can't do that anymore, I guess …"

Fuji's do and display it in the LCD, EVF or OVF too.



Lens is focused a little below 5' and the blue box is the DOF range. You can even set the circle of confusion DOF scale to be film based or digital/pixel based.

Shawn

 

[nongfuspring]

It's not that it doesn't work as well, it's that it's largely been superseded by or because of:

1. Live view/DOF preview: actual DOF visible
2. Fast autofocus: largely negates the need for hyperfocal shooting
3. Variable ISO: ability to shift ISO to suit aperture rather than the other way around
4. Increased resolution: makes focussing errors more obvious

Aside from that I personally I don't think DOF scales were all that useful, not even on film cameras.

 

[Kent]

With high resolution sensors the c-o-c needs to be adjusted to lower numbers.
So the acceptable DoF changes.

 

[Roger Hicks]

It's not that it doesn't work as well, it's that it's largely been superseded by or because of:

1. Live view/DOF preview: actual DOF visible
2. Fast autofocus: largely negates the need for hyperfocal shooting
3. Variable ISO: ability to shift ISO to suit aperture rather than the other way around
4. Increased resolution: makes focussing errors more obvious

Aside from that I personally I don't think DOF scales were all that useful, not even on film cameras.

1 Not really. See my original link. A preview is NOT the final image size or viewing distance.

2 Not really. You can never be sure what autofocus is going to focus on.

3 Only if you have plenty of time.

4 Not really. "Acceptable" DoF is constant on film and digital. All that changes is your definition of "acceptable".

Last para: I've found them a useful guideline for the last 50 years, even if you haven't.

Cheers,

R.

 

[Roger Hicks]

With high resolution sensors the c-o-c needs to be adjusted to lower numbers.
So the acceptable DoF changes.

No. See my original link. And my post immediately above, addressed to nongfuspring.

Cheers,

R.

 

[willie_901]

Wait, do these digital wonder-thingies not have automatic depth-of-field indicator pointers?

Uhm — that was all mechanical, they can't do that anymore, I guess … 😛

Well, some of them do. They display the focus distance and DOF in the finder in real time. Then their owners complain because they take the "indicator pointers" to be absolutes (see Roger's post above). One brand uses a very conservative circle-of-confusion parameter in an attempt (I guess) to minimize disappointments (DOF is somewhat wider than you might expect).

There really isn't a significant difference in thinking about and using DOF between film and digital cameras. I use the word "significant" based on my experiences and expectations. No doubt others will have different views.

 

[shawn]

3 Only if you have plenty of time.

That is where AutoISO comes into play. Set minimum shutter speed you want and you can shoot aperture priority with the camera using your aperture, your minimum shutter and it will set ISO to make it work up to your max ISO.

You can even do this with full manual aperture/shutter. Pentax has their Tav mode and the Fuji's do basically the same thing. Put the camera in Auto ISO and set the camera to manual exposure mode. You set shutter/aperture the camera will set ISO to make it work.

Very quick to shoot this way.

Shawn

 

[radi(c)al_cam]

That is where AutoISO comes into play. Set minimum shutter speed you want and you can shoot aperture priority with the camera using your aperture, your minimum shutter and it will set ISO to make it work up to your max ISO.

Uhm … that's all Greek to me. Why not simply change the film magazine? (Nota bene, I'm definitely one of the younger members here) 😉

 

[Roger Hicks]

That is where AutoISO comes into play. Set minimum shutter speed you want and you can shoot aperture priority with the camera using your aperture, your minimum shutter and it will set ISO to make it work up to your max ISO.

You can even do this with full manual aperture/shutter. Pentax has their Tav mode and the Fuji's do basically the same thing. Put the camera in Auto ISO and set the camera to manual exposure mode. You set shutter/aperture the camera will set ISO to make it work.

Very quick to shoot this way.

Shawn

Dear Shawn,

Fair point. Unless of course your camera had appalling noise at high ISOs, as my Leicas do. I suppose I could use it OK with the DF. It's just that after the M8, M9 and M240, it never occurs to me.

Cheers,

R.

 

[Roger Hicks]

. . . There really isn't a significant difference in thinking about and using DOF between film and digital cameras. I use the word "significant" based on my experiences and expectations. No doubt others will have different views.

Dear Willie,

I am not among them: I think you're absolutely right.

Cheers,

R.

 

[shawn]

I haven’t used the DF but owned a D700 for many years. It works well on that camera with the only slight annoyance being you turn on/off AutoISO from a different menu location from where you set ISO. Not a big deal but it does slow you down a little turning it on or off. Once setup it does a nice job of keeping the ISO as low as possible based on the parameters you set. You should give it a try sometime in variable light to see how it works. It can be a handy tool.

Shawn

 

[Ko.Fe.]

DOF depends on the size of the film or sensor, focal length of the lens, distance to the object and aperture, but not on someone illusion.

Canon 7D (never have) with Canon 50L (sold because it is made with glue and plastic) at one meter and f1.2 will have DOF of two centimeters.
Canon 5D (sold after Canon ended support for it) with the same will have three centimeters of DoF. And same will have film EOS 200 (which I'm still keeping). 🙂

 

[Godfrey]

Yes, but already some 60 years ago, certain Schneider, Voigtländer etc. lenses for 35mm (!) film cameras did have these «automatic» red pointers 🙂

Lots of modern digital cameras have DoF indication on a distance scale when focusing. A couple of my Olympus, Konica-Minolta, and Leica (fixed lens) digital did, for sure. They're just all approximate, just like the ones on those older film cameras and on my Hasselblad V lenses.

G