Zone focus, is everything really in focus?

[Roger Hicks]

As I recall, and I would have to search for my old Photo Technology book, the depth of field scales are based on a 0.03mm Circle of Confusion. . . .

Dear Bruce,

Which is exactly the problem. This is essentially arbitrary, and of little or no use if you make big prints, or look at them too closely. It comes back to my earlier questions: What is acceptable? To whom? At what enlargement size and viewing distance?

These cannot be divorced from the post to which I was replying, from rogue_designer.

Incidentally, the DoF markings on old camera lenses are not always the same. Some manufacturers assumed you were going to make postcard-sized prints; others, that they'd be twice as big, or bigger. Obviously the former could get away with more relaxed standards for depth of field.

Cheers,

R.

 

[tunalegs]

It's not really the question which is meaningless then, but rather the answers.

 

[radi(c)al_cam]

Incidentally, the DoF markings on old camera lenses are not always the same. Some manufacturers assumed you were going to make postcard-sized prints;

(Pre-war) ZEISS lenses for 35mm format, I guess?

 

[wjlapier]

OP, I think you're getting the idea. Everyone has a different tolerance to what is acceptable. I use hyperlocal all the time as I'm a mostly sunny/partly sunny shooter. Those are the conditions I prefer to shoot in. That said, I'm perfectly happy with photos shot with 28-35mm equivalent focal lengths at f/16 hyper focal. I do occasionally zone focus of closer subjects. Couple of examples of what I consider acceptable sharp focus shot with various cameras:

Leica IF with CV 28/3.5 f/16 hyperfocal ( point and shoot ) Velvia ( 100 if I remember correctly )



Fuji GS645s Ektar f/16 hyperfocal ( the GS645s has a rangefinder and meter but i preferred to point and shoot it and not mess with focusing and checking the meter )



The question is, are these sharp enough for me? Yes. For someone else who likes to pixel peep maybe not. I don't shoot for pixelpeepers.

 

[zuiko85]

As a real life example of problems encountered with enlargement size vs DoF when working at a camera store folks would bring some random 3.5 X 5 inch 'album print' with the negative strip and want a 8X10 out of it. I always asked to see the negative first. A quick look would confirm if there was enough detail to make a reasonably sharp enlargement. Folks were usually shocked if they went ahead and had the 8X10 made. There were not many 35mm negs that would stand up to even modest enlargement. Of unsharp negs camera shake was about 70% of the problem and missed focus was the other 30%. This was back in the early 70's when the standard album print size was 3.5X5inch. That size does not place too much demand on sharpness, at least not with casual viewing.

 

[Richard G]

These are interesting questions and good answers, mostly. The Gepetto's Toy Shoppe is a good illustration, giving the illusion of all being sharp. Hyperfocal focusing would have been less helpful here than scale focus, especially with text in the foreground. The particular elements in a scene determine where the compromise in focus sharpness should fall. Many evening photographs by pros at standard film ISOs seem to be impossible when you see the walking human's motion stopped but at the same time so many elements from foreground to distance in focus. This is more about psychology than physics, the photographer knowing where to focus to make the elements sharp enough for the viewer to be satisfied.

 

[NeonKnight]

Hi!

I only have a film Leica so before i test it myself i was wondering if there is a simple answer?

No simple answer and a lot of testing will be necessary. Focusing scales are a good starting point but you also need to take field curvature into consideration. For example, I regularly use a 28 Biogon ZM which exhibits the wavy type. This phenomenon is good for photographing groups of people but when photographing buildings or flat objects I need to stop down to at least f/8 to get what I feel is acceptable focus.

 

[fireblade]

No question is meaningless Roger and I would have expected better coming from you. At the very least it means the person asking the question doesn't know the answer and, if it seems a daft question to you, then it means they probably don't understand the subject well enough to know how to ask the question. Every question deserves an answer - we all were novices once - and your response isn't helpful. You'd be better to not bother.

No, you're wrong. You're not going to like that answer, either. Building on rogue_designer's earlier response I explained WHY it was a meaningless question: "What is acceptable? To whom? At what enlargement size and viewing distance?"

How is that not helpful? Assuming that the OP is not an idiot, he can reflect on acceptability, enlargement size and viewing distance.

A meaningless question is not the same as a daft question, if you can explain to the person asking it why it is meaningless. So don't try to patronize me by "expecting better". You may not have liked the way I phrased it, but that's your problem, not mine.

Cheers,

R.

You really don't get it do you Roger and your arrogant answer "your wrong" goes no way to persuading me otherwise. I'm not wrong - you are.

"he can reflect on acceptability, enlargement size and viewing distance."

Not if he doesn't understand how these things affect dof and you have done nothing to help him understand.

Seems you think you are God's gift to all photographers and anything you say must be correct and should anyone disagree, then they must be wrong. Well that ain't the way it is Roger.

You really don't get it, do you monopix? Your answer is exactly the sort of thing I was expecting.

Which bit of "acceptable" is hard to understand? Who has not noticed that a big picture, looked at from close up, doesn't look as sharp as a smaller picture viewed from further away?

No, I don't think I'm "God's gift to all photographers". I am however confident that I know quite a lot about photography, and as countless people will confirm, I usually try to answer questions to the best of my ability, within the normal constraints of time and space.

You don't like the way I answered the question. Tough. I'd be upset if the criticism had come from the OP, but it didn't. It came from someone who thought it more important to attack someone who was trying to help, rather than to try to throw any light himself on the OP's question-- or to add anything to rogue_designer's post.

If you can help the OP, then why not try to answer the question? Or indeed, to suggest that I might enlarge upon my answer? I preferred to assume that the OP could think for himself, and might soon understand why it's a meaningless question.

Cheers,

R.

Anglo Civil War 😀😀

 

[Roger Hicks]

(Pre-war) ZEISS lenses for 35mm format, I guess?

Dear Alexander,

You've been paying attention again, haven't you?

Cheers,

R.

 

[Roger Hicks]

Anglo Civil War 😀😀

Not really. I'm a Cornishman living in France. He is (presumably) English. The last Anglo-Cornish war, with an (admittedly short lived and unsuccessful) Cornish invasion of Devon, was in 1549. I'm generally pretty happy that Cornwall is part of the UK, but some English people really annoy me. I bet you he'll get pissy about that as well, and say, "But you're English!"

Having just pretty much got over ten months of assorted ailments and surgery, and looking forward to reasonably good health again, I've decided to give up being polite to people who seem to be more interested in being rude or patronizing than they are interested in photography.

Cheers,

R.

 

[goamules]

Exactly. It's a meaningless question...

I'm sure the OP had some meaning in his question.

...I've decided to give up being polite to people who seem to be more interested in being rude or patronizing than they are interested in photography...

Kind of the pot calling the kettle black.

 

[Roger Hicks]

. .. Kind of the pot calling the kettle black.

And you contribute nothing at all to answering the OP's question, but can find the time to indulge in a personal attack.

As I say, I can no longer be bothered to be polite to anyone who makes a hobby of this. Especially when they hide behind a silly name.

Yes, I can be blunt. Yes, I can be misunderstood. I can make mistakes of both substance and style, as do we all. What's your excuse?

Cheers,

R.

 

[Alberti]

In the time I shot film on my M2 I often used a more or less 1/3 - 2/3 rule, using F5.6 or so.
These pictures often came out bland, no real pop or sharpness.

When I got my M8 I quickly realised there was a better way to make images, whith a clear plane of focus. Was not easy to learn, funny enough, with my newer sharp (Karbe) Leica lenses. I also learned the depth scales say nothing (they refer to a postcard size print, not to pixelpeeping).

Nowadays I have found some sonnar lenses that for instance when used at F/4-5.6 allow a new compositional technology: in these lenses the backfocus plane is larger, this keeps a whole subject in a encompassing stage of focus.

I often use a hyperfocal distance on wideangles, where this works (like setting it to 3 m) but that comes along with F/8 or even F/11, so in the end it is the subject/composition that determines the pop.​

 

[jcb4718]

As bsdunek has said, the depth of field ('acceptably sharp') is based on a 0.03mm blur circle i.e. the image of a point source is considered acceptably sharp if it is <0.03mm in diameter. This has nothing to do with lens aberrations, it's a characteristic of any lens. So that lenses can be compared, so you can get a feel for what any lens will do, the 0.03mm has been agreed upon based, as others have said, on some kind of representative viewing conditions. Of course for some this will just be a starting point. I tend to be a little more conservative (about 1 stop when setting the hyperfocal distance).

 

[brbo]

It was a simple question and not at all meaningless. And it was answered in second post.

According to some, you basically need to know EVERYTHING about photography to be able to ask a question in a proper (non-meaningless) way here on RFF. Ridiculous...

 

[rogue_designer]

He wasn't saying it was a bad question, or that it should not be asked. Just that there is no answer that always holds true, it is ultimately too dependent on too many variables up to and including personal preference - thus meaningless. He wasn't insulting the OP.

This exchange reminds me of Richard Feynman answering questions about magnets.
https://youtu.be/wMFPe-DwULM

 

[brbo]

He wasn't saying it was a bad question, or that it should not be asked. Just that there is no answer that always holds true, it is ultimately too dependent on too many variables up to and including personal preference - thus meaningless. He wasn't insulting the OP.

No he wasn't. I said he said it was meaningless.

But, the real question is, how would YOU ask the question in a proper "RFF fashion" if you were in the OP's shoes? Maybe we can then all learn something from this primadona fight...

 

[Roger Hicks]

He wasn't saying it was a bad question, or that it should not be asked. Just that there is no answer that always holds true, it is ultimately too dependent on too many variables up to and including personal preference - thus meaningless. He wasn't insulting the OP.

This exchange reminds me of Richard Feynman answering questions about magnets.
https://youtu.be/wMFPe-DwULM

Thank'ee kindly for the comparison, and for the link, which (as ever with Feynmann) was most entertaining. Indeed it was not my intention to insult the OP, nor do I believe that I did so; but this doesn't stop it being a meaningless question.

The 0.03mm circle is likewise meaningless. It's chosen arbitrarily, or more accurately, as a (fairly) useful compromise. Anyone who thinks it is anything else does not actually understand the subject. As well as varying with viewing distance and magnification, the size of the circle of confusion varies with focal length: in my old Focal Encyclopedia of Photography, there's rather over a page of discussion of what it is and how it's arrived at. The next entry, of four more paragraphs, is under the heading "Circle of Least Confusion" and takes account of the fact that lenses are not in fact perfect.

Anyone can see that in most photographs, some things are more in focus than others: there isn't a block of stuff that's "in focus", with everything in front of it or behind it suddenly "out of focus". From this it requires but a moment's thought to realize that "in focus" is not an absolute, and that "acceptability" varies. I assumed that the OP could work this out for himself. Presumably he did, or at least, he hasn't come back to complain. Unlike some people.

I had no idea when I agreed with your post (that there are so many variables that you can't give a meaningful answer) that I would be so roundly attacked. But there are some people who are so keen to be insulted that they look for insults where none exist; so keen in fact that they will profess themselves insulted when they have nothing to do with the conversation.

Meaningless questions -- those to which there can be no meaningful answer -- are a separate matter from stupid questions. The old saying that "there is no such thing as a stupid question" is only partially correct. For example, "What will happen if I jump off the edge of this cliff" is a pretty stupid question. You will fall, and if it's a big enough cliff with sufficiently unforgiving terrain at the bottom, you will almost certainly die. Which part of that is too hard to work out? None, which makes it a stupid question.

Cheers,

R.

 

[tunalegs]

Well so long as we're being offended by people questioning things on the internet, Roger, I don't think the word "meaningless" means what you think it does.

The original questions are pretty straightforward, and practical answers can be given.

Hi!

Zone focus, is everything really in focus?

No.

If i focus my 28mm elmarit 1.5 meters (5 fett) then using the scale (at f16) everything between 0.8 meters to infinity is in focus. But is that true?

No.

Is it all sharp or is everything kind of in focus but its sharp at 1.5 meters?

It'll be sharp at 1.5 meters.

Everything else in this thread is more or less beside the point, even if it does have some level of meaning.

 

[Steve M.]

I think you're mixing up aperture and focus. Less and more of aperture gives you less and more of a useable focus range. Stop it down all the way, and at infinity that is all the focus you will ever have, but reeling the aperture back will allow you to selectively focus certain distances w/o resetting the aperture. They are used as a tandem, not one by one.