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Hyperfocal distance


povlj

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This may be the wrong place to ask, but here goes anyway:

 

How do I figure out, other than trial and error, what my hyperfocal distances are on my 50mm and 90 mm lenses, at, say, 5.6 and 8 and f/11? I mean the depth of field, minumum in focus distance from camera to infinity at these various apertures and focal lenghts. The markings on the lenses are not very helpful here, being so small to be almost useless.

 

Povl

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I'll try to help, but others know more than me.

 

First, many suggest not putting the infinity symbol on the f stop you actually are using, but go down by 2 stops to be safe. I consider the center of the infinity mark to be infinity, like when you turn the focus knob all the way to the left and it stops on infinity.

 

So if you put infinity on the exact f stop you plan to use on the right side of the depth of field scale, you look at the same f stop on the left of the scale to determine what will be in focus at the closest focus point. Likewise, you do the same with other distance settings by matching what distances are within the selected f stop-both on the left and right sides on the distance (depth of field) scale based on what parts of the image you want to be focus. Thanks all. Try it out and see how it works for you.

 

I am sure there is a much better explanation, but that's mine for now.

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I don't want to start this everlastng debate again:( However, bear a few things in mind. Although hyperfocal focussing is based on DOF and the values lend themselves to mathematical calculations, the basic parameters are, in the end, determined by a subjective asessment, i.e. what the observer experiences as "sharp" in the image.

 

Thus intangibles like image contrast, structure, content and artistic appreciation play an important role, imo the major role.

On top of that the sharpnesss falloff in a digital photograph is more pronounced than on film.

 

These two considerations lead me to dismiss DOF and hyperfocal distance as too unreliable to use. As far as I'm concerned the only sharp part in a photograph is the plane of focus, and, though it may be (nearly) imperceptible, everything else is out of focus.

Edited by jaapv
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[....]How do I figure out, other than trial and error, what my hyperfocal distances are on my 50mm and 90 mm lenses, at, say, 5.6 and 8 and f/11? I mean the depth of field, minumum in focus distance from camera to infinity at these various apertures and focal lenghts. The markings on the lenses are not very helpful here, being so small to be almost uselessl

 

Photography is not particularly friendly to the blind. If the markings on the lenses are so small as to be useless, then sell all your Leica equipment and everything else with such small type and be happy. Just give it up.

 

Or you could read the manual and make marks on the lenses of distances/stops that concern you.

 

Or learn to focus the lens.

Edited by pico
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I don't want to start this everlastng debate again:( However, bear a few things in mind. Although hyperfocal focussing is based on DOF and the values lend themselves to mathematical calculations, the basic parameters are, in the end, determined by a subjective asessment, i.e. what the observer experiences as "sharp" in the image.

 

I agree. There is no absolute 'sharpness', it all depends on what we accept as 'quite sharp', and ultimately, on the eye's limit of resolution.

 

Thus intangibles like image contrast, structure, content and artistic appreciation play an important role, imo the major role.

On top of that the sharpnesss falloff in a digital photograph is more pronounced than on film.

 

Yes indeed. It has been a rule of thumb since the introduction of the Leica that at the eye's close focusing limit (c. 25cm/10") an edge is accepted as 'sharp' if the fuzz around it is no wider than 1/10 of a millimeter. So how wide can it be on the sensor? That is the diameter of the famous circle of confusion. When the industry standard was set in the 1920's, it was assumed that no negative would be enlarged more than 3x, so the circle of c. that depth of field tables were calculated from was 0.033mm – and that standard has not been changed since then! Consequently, the depth-of-field scale on your lenses is pretty useless as is.

 

These two considerations lead me to dismiss DOF and hyperfocal distance as too unreliable to use. As far as I'm concerned the only sharp part in a photograph is the plane of focus, and, though it may be (nearly) imperceptible, everything else is out of focus.

 

Of course everything within a calculated depth of field is not equally sharp. What's just outside it is just a little bit less sharp – or more unsharp – than what's just inside it. But that does not mean that hyperfocal distances and zone focusing are invalid concepts in practice. Zone focusing is quite useful in quick-action street photography. For demonstrations, riots etc. I usually set my 35mm lens to f:8 and 4 meters.

 

The best course of action is to set the lens using the d.o.f. markings two stops more open than the f-stop you are actually using. That means that you are drawing the line at a circle of confusion that is just half the diameter of the 'standard', that is, c. 0.016mm. So if the 35mm lens is set to f:8 and c. 4 meters, you get acceptable sharpness from abt. 2.5 to 7 meters. For precise work, you point-focus of course.

 

But when using longer lenses, which have a more shallow depth of field, zone focusing is too inaccurate to be useful. So with lenses from 50mm on, I do as Jaap does – point focus, just stopping down a little bit to get more 'elbow room' in my focusing.

 

The old man from the Age of Guess Focusing

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Pico, I don't think the Original Poster means that the actual numerals are too small to see. He means that the divisions between the lines marking the d.o.f. are so close that it is impossible to relate them to the widely spaced numbers that denote subject distance. And they mostly are, making them pretty useless.

 

For instance, if I set my 35mm lens to 3m, how much d.o.f. do I have at f:4, even if I accept the ludicrous 1920's circle of confusion? Impossible to say. And the corresponding lines on a 90mm lens are simply silly. Rightly understood, the question is perfectly valid.

 

So there's no call to use the kind of language you are throwing at this person, simply because he is (maybe) not too felicitous in his use of words.

 

The old man from the Age of Civility

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I agree. There is no absolute 'sharpness', it all depends on what we accept as 'quite sharp', and ultimately, on the eye's limit of resolution.

 

 

 

Yes indeed. It has been a rule of thumb since the introduction of the Leica that at the eye's close focusing limit (c. 25cm/10") an edge is accepted as 'sharp' if the fuzz around it is no wider than 1/10 of a millimeter. So how wide can it be on the sensor? That is the diameter of the famous circle of confusion. When the industry standard was set in the 1920's, it was assumed that no negative would be enlarged more than 3x, so the circle of c. that depth of field tables were calculated from was 0.033mm – and that standard has not been changed since then! Consequently, the depth-of-field scale on your lenses is pretty useless as is.

 

 

 

Of course everything within a calculated depth of field is not equally sharp. What's just outside it is just a little bit less sharp – or more unsharp – than what's just inside it. But that does not mean that hyperfocal distances and zone focusing are invalid concepts in practice. Zone focusing is quite useful in quick-action street photography. For demonstrations, riots etc. I usually set my 35mm lens to f:8 and 4 meters.

 

The best course of action is to set the lens using the d.o.f. markings two stops more open than the f-stop you are actually using. That means that you are drawing the line at a circle of confusion that is just half the diameter of the 'standard', that is, c. 0.016mm. So if the 35mm lens is set to f:8 and c. 4 meters, you get acceptable sharpness from abt. 2.5 to 7 meters. For precise work, you point-focus of course.

 

But when using longer lenses, which have a more shallow depth of field, zone focusing is too inaccurate to be useful. So with lenses from 50mm on, I do as Jaap does – point focus, just stopping down a little bit to get more 'elbow room' in my focusing.

 

The old man from the Age of Guess Focusing

 

I think , Lars, that we quite agree. Only I find that my Summilux 24 wide open is as dodgy at zone focussing as any 50 or 90 mm lens ;)

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I think , Lars, that we quite agree. Only I find that my Summilux 24 wide open is as dodgy at zone focussing as any 50 or 90 mm lens ;)

 

Not wanting to get into this discussion (as I know DOF is ethereal and subjective), still, being aware of hyperfocal distance on certain lenses in certain circumstances does come in handy. And though, I usually use the markings on the lens, I will sometimes use the iPhone app pCam for DOF and hyperfocal calculations. It also has other functions for planning shots.

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I think , Lars, that we quite agree. Only I find that my Summilux 24 wide open is as dodgy at zone focussing as any 50 or 90 mm lens ;)

 

It is, of course – because at f:1.4, its d.o.f. is as shallow as that of many a lens with far longer focal length and smaller maximum aperture.

 

But if I had a Summilux 24, I would not dream of using it wide open for quick-action street photography. And that btw also goes for the 35mm Summilux that was the lens before me when I made those comments about zone focusing. That is an extremely useful lens both wide open and stopped down – but each f-stop in its appropriate place. As I use to say, scratches for itches.

 

The old man from the Age of Guess Focusing (with a 6x9cm folder, at that)

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Just the thread I wanted, I was out yesterday taking pictures of my favourite personal subject - which could be described as unruly forests, what I aim to capture is something of the experience of standing in a very messy scene (or shall we say loosely composed) but as you look at it things of interest start to pop out at you or catch your attention.

 

I would say I'm mathematically challenged and my brain seems to zone out as soon as equations etc are mentioned. I took 3 cameras, M8 with Summicron 50 = about 60mm ,set at f8 would have gone smaller but have heard that there's some degradation past 8 (would love to hear what this actually means), a Fuji 6x7 90mm lens = 50mm, and a 35mm film camera with a 45mm.

 

On all 3 cameras I roughly set infinity to the f stop I had chosen to use marked on the right hand side.

 

I haven't seen the film results yet but on the M8 the theory seems to work pretty well, roughly everything between 5ft and in infinity in reasonable focus. Another way of saying it is that as expected some of the foreground was out of focus. Easy to crop out which is OK by me.

 

Q: Is there a better in the field, on the run, quick rule of thumb method of getting the maximum amount of your scene in focus.

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Pico, I don't think the Original Poster means that the actual numerals are too small to see. He means that the divisions between the lines marking the d.o.f. are so close that it is impossible to relate them to the widely spaced numbers that denote subject distance. And they mostly are, making them pretty useless.

 

I agree that I was rude to povljorgensen, and completely missed his point. I will try to make up for that.

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Well, for landscape the most effective way is to set your camera on a tripod, take four or five shots at differenf focussettings, stack them in Photoshop, and using layer masks and a brush, blend them to one sharp-from-front-to-back image.

Just the thread I wanted, I was out yesterday taking pictures of my favourite personal subject - which could be described as unruly forests, what I aim to capture is something of the experience of standing in a very messy scene (or shall we say loosely composed) but as you look at it things of interest start to pop out at you or catch your attention.

 

I would say I'm mathematically challenged and my brain seems to zone out as soon as equations etc are mentioned. I took 3 cameras, M8 with Summicron 50 = about 60mm ,set at f8 would have gone smaller but have heard that there's some degradation past 8 (would love to hear what this actually means), a Fuji 6x7 90mm lens = 50mm, and a 35mm film camera with a 45mm.

 

On all 3 cameras I roughly set infinity to the f stop I had chosen to use marked on the right hand side.

 

I haven't seen the film results yet but on the M8 the theory seems to work pretty well, roughly everything between 5ft and in infinity in reasonable focus. Another way of saying it is that as expected some of the foreground was out of focus. Easy to crop out which is OK by me.

 

Q: Is there a better in the field, on the run, quick rule of thumb method of getting the maximum amount of your scene in focus.

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Jaap - looks like I'll be teaching myself yet another skill.........but then I had a bit of think about this, focus stacking would work on absolutely still scenes but as mine really have quite lot going on throughout the near & middle distance any wind at all would cause quite a few problems. Though it could be interesting to see what the merging program decided to do with leaves and branches in slightly different positions.

 

Seems like the ideal solution is a 50mm lens with the same dof as a 21 at f16, giving me 0.5m to infinity

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Hello Everybody,

 

If you have a black lens you might find the darkening of superfluous engraved Depth Of Field lines useful.

 

For example: On my Tele-Elmar I darkened the 5.6, 8 & 16 w/ a marking pen leaving: The center line w/ indicator to know where the lens is focussed. The F4 to remind me a 135mm lens effectively has no depth of focus @ F4. F11 because that is an important stop. F22 because that is the smallest stop & has the greatest depth of field.

 

Emminently more readable than before. The now black engraved lines of the other F stops are still there if I want to know the positions of the intermediate stops.

 

Whichever focal length lens I am using I always consider 2 stops smaller as the minimum acceptable ammount to set to have any appreciable depth of field.

 

Best Regards,

 

Michael

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I took three cameras, M8 with Summicron 50 = about 60 mm

The Summicron 50 is 50 mm, not 60 mm. That's why it has "50" engraved on the barrel.

 

 

... set at f/8 would have gone smaller but have heard that there's some degradation past f/8 ...

Not if you're after wide depth-of-field.

 

 

... (would love to hear what this actually means) ...

This topic has been discussed to death over and over on all photography forums, including this one. Hint: Search for keyword "diffraction" ... but just "DOF" and "degradation" should bring up lots of results, too.

 

However ... if you're mathematically challenged (as you say) and mostly interested in how to get actual results in the field quickly and easily then I strongly recommend to avoid searching for "diffraction". It will be mostly deceiving anyway. The rule actually is very straightforward: Stop your lens down until you get the depth-of-field you want. As simple as that.

 

Another—even simpler—rule is this: If your composition has one main subject then focus on that. (After that, you may apply the previous rule if required.)

 

Another—not quite so simple—rule is this: If your composition has several main subjects then focus on the nearest. However the exceptions to this rule are comparatively numerous ... that's why it's considered not so simple.

 

 

On all three cameras I roughly set infinity to the f-stop I had chosen to use marked on the right-hand side.

This is exactly the way how to do it. It even works with tight DOF scales and sparse distance scales. You don't have to set the lens to a particular distance (as the original poster indirectly suggests). All you need is the distance scale's infinity symbol.

 

However be aware that using hyperfocal distance maximises depth-of-field formally but it does not yield good sharpness at infinity. Instead, sharpness at infinity will be just barely acceptable. So I'll repeat what Jaap said: If you want a sharp horizon then focus at infinity. Keep in mind that details at the horizon are tiny so they need good sharpness. Details in the foreground are big so they can get away with some less-than-perfect sharpness. Let's call this "relative sharpness"—the degree of sharpness should match the size of the smallest detail you want to resolve. And far-away detail is always smaller than close-up detail. Hyperfocal focusing, however, is about absolute sharpness; it does not take the different apparent sizes of far-away and close-up details into consideration. That's why hyperfocal focusing is a bad concept. I rarely use it, if at all.

 

This previous paragraph basically is a quick run-down of Harold Merklinger's article "The Ins and Outs of Focus". It's a PDF document floating around on the Internet; you can google for it. There you can read about the concept of "relative sharpness" in great length and overwhelming depth ... albeit Merklinger does not call it that way; this term is my own invention. However I'm afraid it's not suitable reading for the mathematically challenged ;)

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Pico, I don't think the Original Poster means that the actual numerals are too small to see. He means that the divisions between the lines marking the d.o.f. are so close that it is impossible to relate them to the widely spaced numbers that denote subject distance. And they mostly are, making them pretty useless.

 

For instance, if I set my 35mm lens to 3m, how much d.o.f. do I have at f:4, even if I accept the ludicrous 1920's circle of confusion? Impossible to say. And the corresponding lines on a 90mm lens are simply silly. Rightly understood, the question is perfectly valid.

 

So there's no call to use the kind of language you are throwing at this person, simply because he is (maybe) not too felicitous in his use of words.

 

The old man from the Age of Civility

I have accepted PICO's apology, and will acknowledge that perhaps I was less than "felicitous" in my choice of words. That all said, thank you all for comments. I do not wish to engage in circle of confusion debates, but instead am content with taking the experienced advice of using dof markings two stops more open than f stop actually used. Will go practice that in the back yard. For example, @ f/11 with 50mm lens I should expect "in-focus" results from 6 meters, rather than 4.

Thank you all again.

And Merry Christmas.

 

Povl

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