A poll about depth of field

[sybersitizen]

The lens for the shot below was set at its infinity stop and closed down to f/2.8. Disregarding the actual optical limitations of the lens, the distant stars are commonly considered in DOF tables to be 'in acceptable focus' ... but the nearby chimney is not 'in acceptable focus'.

The question: Is the depth of field in this shot infinite?

 

[tkbslc]

Infinity focus does not mean “infinite” DOF, any more than 2m focus distance means 2m of DOF.

I voted no.

 

[jvc1]

The depth of field is infinite, the depth of focus is not.

 

[PK24X36NOW]

The depth of field focus distance is infinite , the depth of focus is not.

Fixed it for you.

 

[jvc1]

The depth of field focus distance is infinite , the depth of focus is not.

Fixed it for you.

I was using the OP's words. His question wasn't "is the focus distance infinite".

 

[tkbslc]

The depth of field focus distance is infinite , the depth of focus is not.

Fixed it for you.

I was using the OP's words. His question wasn't "is the focus distance infinite".

Why is why the answer was "no".

 

[Brev00]

Nothing is infinite . . . except the capacity for human error

 

[rurikw]

though I voted maybe. Does the field extend beyond the limit of the observable universe? If not it's only about 45ly deep.

 

[JustUs7]

The depth of field is a ray (or a field as the case may be) beginning at the hyper-focal distance stretching to infinity. Unless I read my handy dandy depth of field calculator wrong.

 

[Tom Axford]

Infinity focus does not mean “infinite” DOF, any more than 2m focus distance means 2m of DOF.

I voted no.

If you define depth of field in the usual way (as a precise mathematical concept), then if the lens is focussed on something further away than the hyperfocal distance, the depth of field is always infinite.

That follows from the mathematics, but it may not necessarily agree with someone's colloquial understanding of the word infinity.

 

[tony field]

The depth of field is infinite, the depth of focus is not.

Depth of focus is measured at the sensor plane and is in the order of micron distances.

--
Charles Darwin: "ignorance more frequently begets confidence than does knowledge."
tony

 

[newmikey]

Use a DOF calculator:

On an APS-C sensor with a 50mm lens at f2.8 focused at infinity, the near focus point is at 44.19 meter. That chimney looks a lot closer and is therefore not in sharp focus. It looks about 3-5 meters away so you'd need at least f8 to get it into acceptable focus at your lens' infinity setting.

 

[sybersitizen]

Use a DOF calculator:

On an APS-C sensor with a 50mm lens at f2.8 focused at infinity, the near focus point is at 44.19 meter. That chimney looks a lot closer and is therefore not in sharp focus. It looks about 3-5 meters away so you'd need at least f8 to get it into acceptable focus at your lens' infinity setting.

This was the question: Is the depth of field in this shot infinite? What's your answer?

If you prefer, use the settings you describe above to obtain the image at f/8, and assume the chimney is rendered 'in acceptable focus' instead, then vote for an answer. Keep in mind that the calculator says there will still have to be a near limit to the depth of field even if the content of the f/8 photo doesn't visually depict it.

 

[justinwonnacott]

DOF is a furry concept which depends on a value judgement that expresses what "acceptable sharpness" is when defined as a lens circle of confusion paired with a particular image size/viewing distance. One person's sharp is another person's out of focus, hyperfocal distance is closely related.

It should be called WITZTISFEFM, "what is the zone that is sharply focused enough for me". Digital and film shooters rarely agree on this.

 

[sybersitizen]

DOF is a furry concept which depends on a value judgement that expresses what "acceptable sharpness" is when defined as a lens circle of confusion paired with a particular image size/viewing distance. One person's sharp is another person's out of focus, hyperfocal distance is closely related.

It should be called WITZTISFEFM, "what is the zone that is sharply focused enough for me". Digital and film shooters rarely agree on this.

This was the question: Is the depth of field in this shot infinite? What's your answer?

 

[justinwonnacott]

DOF is a furry concept which depends on a value judgement that expresses what "acceptable sharpness" is when defined as a lens circle of confusion paired with a particular image size/viewing distance. One person's sharp is another person's out of focus, hyperfocal distance is closely related.

It should be called WITZTISFEFM, "what is the zone that is sharply focused enough for me". Digital and film shooters rarely agree on this.

This was the question: Is the depth of field in this shot infinite? What's your answer?

No of course not. But a pinhole would create an image that is equally "out of focus" at pretty well any distance from the objective but what size pinhole is that? And so what of it?

 

[TacticDesigns]

Just trying to imagine what something at infinity would look like captured by one of our cameras.

Take care & Happy Shooting!

 

[Barry Twycross]

Just trying to imagine what something at infinity would look like captured by one of our cameras.

Take care & Happy Shooting!

Geometrically, an infinitely small point, and thus invisible, or maybe it might show up as a single pixel (subject to lens aberration).

Physically, the light hasn't reached you yet, thus invisible.

 

[Phil A Martin]

Just trying to imagine what something at infinity would look like captured by one of our cameras.

Take care & Happy Shooting!

Geometrically, an infinitely small point, and thus invisible, or maybe it might show up as a single pixel (subject to lens aberration).

Physically, the light hasn't reached you yet, thus invisible.

It's not invisible, it hasn't arrived yet.

 

[Barry Twycross]

Just trying to imagine what something at infinity would look like captured by one of our cameras.

Take care & Happy Shooting!

Geometrically, an infinitely small point, and thus invisible, or maybe it might show up as a single pixel (subject to lens aberration).

Physically, the light hasn't reached you yet, thus invisible.

It's not invisible, it hasn't arrived yet.

And never will, seems invisible to me.