Doug Kerr
Well-known member
In depth of field calculations, we essentially answer this question:
With the camera focused at a certain distance, and with a certain focal length lens, an a certain aperture, over what range of distances may we have objects whose images are not blurred by greater than some degree we establish.
We can of course "solve" this relationship "in other directions"; for example we may ask, "to have objects over a certain range of distances whose images are not blurred by greater than some degree we establish, for a certain focal length, what aperture must we use?
In some cases, we are interested in assuring blurring of background or foreground objects as part of the artistic objectives of the result - the matter of "bokeh".
The equations governing this are the same as for the first interest, but we use them a different way up.
This calculator, in the form of an Excel spreadsheet, can help us project what will happen in this regard:
http://dougkerr.net/pumpkin/articles/OFB_calculatorP.xls
Best regards,
Doug
With the camera focused at a certain distance, and with a certain focal length lens, an a certain aperture, over what range of distances may we have objects whose images are not blurred by greater than some degree we establish.
We can of course "solve" this relationship "in other directions"; for example we may ask, "to have objects over a certain range of distances whose images are not blurred by greater than some degree we establish, for a certain focal length, what aperture must we use?
In some cases, we are interested in assuring blurring of background or foreground objects as part of the artistic objectives of the result - the matter of "bokeh".
The equations governing this are the same as for the first interest, but we use them a different way up.
This calculator, in the form of an Excel spreadsheet, can help us project what will happen in this regard:
http://dougkerr.net/pumpkin/articles/OFB_calculatorP.xls
Best regards,
Doug