Zone focus, is everything really in focus?

I think it is better to ask if the 0.03mm circle is useful or not rather than meaningless or not. This limit, or a similar limit, is the basis of the depth of field scale engraved on a lens barrel. Now if, for example, I want infinity to be in focus and ask: how can I maximise the foreground that will also be in focus, I set the hyperfocal distance via the lens depth of field scale. Experience or personal preference or a compromise about what is to be in focus may make me adjust the focus further. As I said, I tend to be conservative when setting the hyperfocal distance (so in theory infinity is 'even sharper'). Usually I'm happy with the end result, at least in terms of sharpness! The point is the depth of field scale is my starting point and to that extent it is useful.
 
I think it is better to ask if the 0.03mm circle is useful or not rather than meaningless or not. This limit, or a similar limit, is the basis of the depth of field scale engraved on a lens barrel. Now if, for example, I want infinity to be in focus and ask: how can I maximise the foreground that will also be in focus, I set the hyperfocal distance via the lens depth of field scale. Experience or personal preference or a compromise about what is to be in focus may make me adjust the focus further. As I said, I tend to be conservative when setting the hyperfocal distance (so in theory infinity is 'even sharper'). Usually I'm happy with the end result, at least in terms of sharpness! The point is the depth of field scale is my starting point and to that extent it is useful.
As soon as you say "a similar limit" you have admitted that the 0.03mm is essentially arbitrary. Also, there are no standards for DoF scales engraved on lens barrels. To pretend the The Circle Of Confusion Is 0.03mm In All Circumstances betrays an ignorance of what a circle of confusion is, and how it is used in calculating depth of field. (I'm not accusing you of this, by the way, because you already understand it).

As you say, DoF scales are useful to a modest extent, as a starting point, to be modified by experience.

Cheers,

R.
 
You really don't get it, do you monopix?

Actually I do Roger - I get YOU completely and having now realised what a ****************** you are I won't be wasting any more of my time on you. The only reason for replying again is to correct your factually incorrect reply.

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

Obviously you were too busy trying to justify your own pointless offerings that you missed my reply completely so here it is again.

No simple answer as you've probably realised.

I would recommend reading The Ins and Outs of focus by Harold Merklinger. You can read it/download it at http://www.trenholm.org/hmmerk/TIAOOFe.pdf

Not everyone would agree with his recommendations but he does explain the issues and has some good examples.

Merklinger's book gives the best explanation I know of this issue and recommending it is, therefore, the best answer I can give. Maybe you should compare Merklinger's description with what you've written so far in this thread and consider who's answer is, potentially, most useful to the OP.
 
Hi!

Zone focus, is everything really in focus? 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? Is it all sharp or is everything kind of in focus but its sharp at 1.5 meters? I only have a film Leica so before i test it myself i was wondering if there is a simple answer?

The simple answer, is that critical focus is only at the 1.5 meters area with a few centimeters on either side (depending on the focal length and distance to the subject). The areas either side grow further out of focus, the further from 1.5 meters you are.

Let me introduce you to a tool I find useful

http://www.dofmaster.com/dofjs.html

Choose 35mm film as a starting point, try various combinations of f/stop, then try different distances, then try wider or longer lenses. You should quickly get an intuitive grasp about how focus works.

You can pick from a variety of different camera types, and sizes of film. Also at the very bottom, there's a long list of circles of confusion, which could be used instead.

So as a longer answer, good focus depends on your purpose for the image, how it will be presented, and the subject matter. An image can look fine downsized on the web to 1000 pixels, but look terribly blurry as an 11x14 print. No one should care about seeing every eyelash in a street photograph, but in a portrait, having the eyes out of critical focus is usually a bad idea.

Like all things photographic, there's no limit to the depth of the subject, but since you likely just want to make photographs, an intuitive understanding is usually quite good enough. Have you only used a rangefinder, and never an SLR? If you do have an SLR or a chance to borrow one, I'd recommend playing around with the focus a bit while stopping down the lens to see what happens rather than trying to imagine how a rangefinder would render the scene.
 
Actually I do Roger - I get YOU completely and having now realised what a ****************** you are I won't be wasting any more of my time on you.. . . .
Good. Kindly put me on ignore. I will return the compliment. I apologize for not noticing your recommendation of Merklinger's book but I was understandably upset by your aggression; which, to judge from the above, is your standard modus operandi. You really are a very angry person. Ask yourself: how much good has it done you over the years?

Cheers,

R.
 
The simple answer, is that critical focus is only at the 1.5 meters area with a few centimeters on either side (depending on the focal length and distance to the subject). The areas either side grow further out of focus, the further from 1.5 meters you are.

Let me introduce you to a tool I find useful

http://www.dofmaster.com/dofjs.html

Choose 35mm film as a starting point, try various combinations of f/stop, then try different distances, then try wider or longer lenses. You should quickly get an intuitive grasp about how focus works.

You can pick from a variety of different camera types, and sizes of film. Also at the very bottom, there's a long list of circles of confusion, which could be used instead.

So as a longer answer, good focus depends on your purpose for the image, how it will be presented, and the subject matter. An image can look fine downsized on the web to 1000 pixels, but look terribly blurry as an 11x14 print. No one should care about seeing every eyelash in a street photograph, but in a portrait, having the eyes out of critical focus is usually a bad idea.

Like all things photographic, there's no limit to the depth of the subject, but since you likely just want to make photographs, an intuitive understanding is usually quite good enough. Have you only used a rangefinder, and never an SLR? If you do have an SLR or a chance to borrow one, I'd recommend playing around with the focus a bit while stopping down the lens to see what happens rather than trying to imagine how a rangefinder would render the scene.
Dear Mich,

That sums it up, really. There is no meaningful answer short of "try it and see".

Cheers,

R.
 
one thing, which, though I am sure that you guys will be aware of, possibly is worthwhile to remind of, quote:
"The further your pre-focused distance, the deeper the Depth of Field. A subjected focused at 1 meter away might give you a range in focus from .2 meters in front and .3 meters behind the subject, a total DOF of .5 meters. A subject focused at 3 meters away might give you a range in focus from 1.5 meters in front and 10 meters behind the subject, a total DOF of 11.5 meters."
( taken from: http://shooterfiles.com/2016/02/how-to-zone-focus-street-photography-101/ + another site: https://www.streethunters.net/blog/...using-hyperfocal-distance-street-photography/ )

also possibly worthwhile to remind is that the area that appears to be sharp "in front" of the exact focus plane is much shorter than the area that appears sharp "behind" it. ( I have little experience using zone focus but when I tried sometimes, too often is happenend that I focused too far away, but it never has happenend that I had focused too short. It might be a good practice to "rather" focus "short" )
 
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