Infinity Focusing

I read an article on luminous-landscape recently about the technique called infinity focusing. So, while I was out in the field, I thought I'd try it.

I'm intrigued:



Anybody have other examples to share?

Hi, Ed,

Could you give us a link to the article? I'm not sure just what that technique is.

Thanks.

The Link: Digital Focusing Part Two

The technique is really a guide to know what level of detail will be discernable in the foreground for any given aperture when focus is set to full infinity.

When I took this photo, I planned on the rows between the grass being prominent, but not the detail of the grass itself. Just a different way to evaluate the image you want to make...

Hi, Ed,

Edward Bussa said:

The Link: Digital Focusing Part Two

Click to expand...

Thanks. Very interesting.

The technique is really a guide to know what level of detail will be discernable in the foreground for any given aperture when focus is set to full infinity.

Click to expand...

This can also be calculated by my out of focus blur performance spreadsheet, available here:

http://doug.kerr.home.att.net/pumpkin/OFB_calculator.xls

It will show you, for focus at any distance (e.g., infinity) the degree of blurring produced in the image for objects at any other distance. The blurring is quantified in terms of the diameter of the resulting circle of confusion (not to be confused with the maximum diameter of the circle of confusion that we consider allowable in depth of field calculations - the "circle of confusion diamater limit, or COCDL).

The COC diamater (C) is of course as it occurs in the image itself (on the film or digital sensor). You will need to conclude just what a certain size means by considering the size at which the image is expected to be viewed.

You can enter (as c) the COCDL (circle of confusion diameter limit) you consider useful in DOF calculations for the format size in use. Then the value B in right hand panel will interpret the COC diameter (for the blurring being studied) as a ratio to that COCDL (a concept pioneered by Leon Witwer).

Edward Bussa said:

The Link: Digital Focusing Part Two

The technique is really a guide to know what level of detail will be discernable in the foreground for any given aperture when focus is set to full infinity.

When I took this photo, I planned on the rows between the grass being prominent, but not the detail of the grass itself. Just a different way to evaluate the image you want to make...

Click to expand...

The link to the original article on "infinity focusing" is: http://www.trenholm.org/hmmerk/DOFR.html

"Depth of Field Revisited: by Harold M. Merklinger really takes a different view (from DOF theory and calcs) of what is required to get the maximum resolution of the desired elements in an image. It really seems to make a lot of sense.

John