Check out Software and Computer Support for Photographers section of our forum.
question about DOF
May 10, 2012 16:02:45 #
When one focuses on a given point, say the eyes of an insect, then it stands to reason that there will be a distance that's in focus in FRONT of the eyes, and a depth that's in focus BEHIND the eyes. But I have no idea HOW MUCH.
You could say the same thing about a bird perched on a branch. I know it depends on what f stop you use, but the principle should be the same, maybe expressed as a percentage? A ratio?
I've tried a Google search to find some reference to this, but have come up short.
Ideas?
You could say the same thing about a bird perched on a branch. I know it depends on what f stop you use, but the principle should be the same, maybe expressed as a percentage? A ratio?
I've tried a Google search to find some reference to this, but have come up short.
Ideas?
May 10, 2012 16:06:57 #
Google DOF calculator. The math is tricky because it depends on the focal length of the lens, f stop used and distance to the subject. There are calculator apps you can get for iphones, and androids I think.
May 10, 2012 16:17:52 #
Here is one to consider....
http://www.expoimaging.com/product-detail.php?cat_id=4&product_id=4&keywords=ExpoAperture2_Depth-of-Field_Guide
Well, after seeing the bottom of the page of the above link, I would suggest going for the pocket version.....
Pat
http://www.expoimaging.com/product-detail.php?cat_id=4&product_id=4&keywords=ExpoAperture2_Depth-of-Field_Guide
Well, after seeing the bottom of the page of the above link, I would suggest going for the pocket version.....
Pat
Check out Bridge Camera Show Case section of our forum.
May 10, 2012 16:26:47 #
Magnification and the distance you are from the subject also affects the DOF. The closer you are or the higher the magnification, the less DOF.
The ratio of in front to behind subject is apparently dependent on what's called the hyperfocal distance (the closest focussing distance where the DOF extends to infinity.) There is some information on Wikipedia about DOF, including the math formulae if you care to try them! There is a paragraph on near:far distance, a short way down the page.
http://en.wikipedia.org/wiki/Depth_of_field
The ratio of in front to behind subject is apparently dependent on what's called the hyperfocal distance (the closest focussing distance where the DOF extends to infinity.) There is some information on Wikipedia about DOF, including the math formulae if you care to try them! There is a paragraph on near:far distance, a short way down the page.
http://en.wikipedia.org/wiki/Depth_of_field
May 10, 2012 16:27:33 #
1/3rd in front of the point of focus;
2/3rds behind.
I've heard that the farther away the subject is, that ratio evens out. Not sure if it's true.
2/3rds behind.
I've heard that the farther away the subject is, that ratio evens out. Not sure if it's true.
May 10, 2012 16:35:03 #
Roger Hicks
Loc: Aquitaine
As GoofyNewfie says, there's usually more behind than in front. But a lot depends on lens design and aperture. It's also a lot easier to understand with manual cameras: see http://www.rogerandfrances.com/subscription/ps%20how%20zone%20focus.html and http://www.rogerandfrances.com/subscription/ps%20basics%20focus%20d-o-f.html
Cheers,
R.
Cheers,
R.
May 11, 2012 10:07:52 #
Pablo8
Loc: Nottingham UK.
It is generally accepted that the 1/3rd to 2/3rds stands as a rule of thumb for most situations. However, the lenses computed for my 5" x 4" camera are said to be equal distances fore and aft from the focussed point. But then, my Sinar has so many options for selective focus. In the good old days, focus ranges were marked on the barrel of lenses, where one could quickly set the hyperfocal distance. Best example of this, was the Hasseblad lenses where the two extremes of focus range were shown by a pair of moving red markers.These moved wider and closer, as the aperture was selected.
Check out Black and White Photography section of our forum.
May 11, 2012 10:10:23 #
gym wrote:
...But I have no idea HOW MUCH.
...
I've tried a Google search to find some reference to this, but have come up short.
Ideas?
...
I've tried a Google search to find some reference to this, but have come up short.
Ideas?
http://www.dofmaster.com/dofjs.html
That will answer your questions.
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.
Check out Commercial and Industrial Photography section of our forum.