Lens Aperture DOF Chart
Jan 5, 2021 11:47:32 #
BurghByrd
Loc: Pittsburgh
BebuLamar wrote:
I wonder if you can post a chart that you have. It seems such a chart must be quite long.
Will this work?
Jan 5, 2021 14:50:34 #
There is a mathematical formula that relates DOF and Aperture, but you have to determine a circle of confusion which is where the argument begins. In film days it was related to the silver halide grain size. The formula is derived in most optics theory text books.
Jan 5, 2021 14:57:58 #
Jan 5, 2021 15:34:26 #
Here's the formula to calculate the Depth of Field. It's of great importance to know what it is when doing macro photography were it is razor thin at higher magnifications.
The calculation is (measured in millimeters):
DOF = (0.0022*N*N*(m+1)*(m+1))/(m*m) , where N is the F-number and m is magnification.
For Example: F-number 5.6 and magnification 0.50 computes as DOF = (0.0022*5.6*5.6*(0.50+1)*(0.50+1))/(0.50*0.50) = 0.6209mm
The calculation is (measured in millimeters):
DOF = (0.0022*N*N*(m+1)*(m+1))/(m*m) , where N is the F-number and m is magnification.
For Example: F-number 5.6 and magnification 0.50 computes as DOF = (0.0022*5.6*5.6*(0.50+1)*(0.50+1))/(0.50*0.50) = 0.6209mm
Jan 5, 2021 16:12:39 #
BurghByrd
Loc: Pittsburgh
BebuLamar wrote:
I don't understand the table. Where is the focus distance?
The focus distance is in the top left corner but you have a point, it's an input cell in a spread sheet so as a print out it's of little use. I'm sorry. On the other hand it's relatively easy to put a spreadsheet together using the previously provided formula or using one of the readily available phone apps.
Jan 5, 2021 16:16:43 #
Alphabravo2020 wrote:
Any ideas on the best way to generate an aperture/DOF chart for a prime lens?
Some of my old Nikon lenses have such a chart in the users manual but I can't seem to find one for a 58mm Voigtlander. It looks to be a pretty tedious exercise but it might be a good learning experience.
TIA
Some of my old Nikon lenses have such a chart in the users manual but I can't seem to find one for a 58mm Voigtlander. It looks to be a pretty tedious exercise but it might be a good learning experience.
TIA
I use Hyper Focal Pro on my Android. Simple, and it goes whith you.
Jan 5, 2021 17:21:43 #
I use "scantips.com". He has working charts so you can figure DoF in a few ways, including distance in front of and behind the point of focus.
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