View Full Version : Is there such thing as a "DOF rule of thumb"?
pedro.m.reis
06-13-2007, 05:06
I know that there are many programs that i can use to calculate the DOF of a giving lens and aperture. But i was wondering if there is a DOF rule of thumb or a manual calculator that i can use. Anyone knows such thing?
Hi,
thats a quite difficult question. The best experience in my opinion is to use the scale on a manual lens.
Because the depth of field is no linear function that depends on various factors a separate table only can be handy for one format and the specific lens.
For Palm-PDAs there is a nice program that might be useful for practic photography in the field.
Regards, Axel
This is an infomative thread:
http://rangefinderforum.com/forums/showthread.php?t=26541&highlight=dof
I made up a set of these in the different focal lengths I have, laminated them, and carry them w/ me wherever I go. See http://www.dofmaster.com/doftable.html.
Jonathan R
06-13-2007, 06:39
I strongly recommend you read Harold Merklinger's 'In and Outs of Focus', available at http://www.trenholm.org/hmmerk/download.html.
It gives very practical rules of thumb, and will change your view of DOF completely.
antiquark
06-13-2007, 06:59
Here's a couple of rules that are useful ONLY if you're using a 50mm lens and 35 film:
- The DOF at 2 meters is the f-stop times ten, in centimeters. E.g., if you're focusing at 2 meters, at f/2.8, then your DOF is 28 cm, or about a one foot.
- If you halve the distance, then you quarter the DOF. Using the previous example, if you halved the distance to 1 meter, then the DOF would be quartered from 28 to 28/4 or 7 cm.
- Double the distance and you quadruple the DOF. Using the first example, if you doubled the distance to 4 meters, then the DOF would be quadrupled from 28 to 28*4, or 112 cm.
If you use a 35mm lens, you can use the same rule but multply the DOF by two. Thus, at 2 meters, f/2.8, the DOF would be 28*2 = 56 cm.
Hope that helps.
pedro.m.reis
06-13-2007, 07:06
Usefull tips as usual :).
I have o lot to read now :)
shadowfox
06-13-2007, 07:53
Here's a couple of rules that are useful ONLY if you're using a 50mm lens and 35 film:
- The DOF at 2 meters is the f-stop times ten, in centimeters. E.g., if you're focusing at 2 meters, at f/2.8, then your DOF is 28 cm, or about a one foot.
- If you halve the distance, then you quarter the DOF. Using the previous example, if you halved the distance to 1 meter, then the DOF would be quartered from 28 to 28/4 or 7 cm.
- Double the distance and you quadruple the DOF. Using the first example, if you doubled the distance to 4 meters, then the DOF would be quadrupled from 28 to 28*4, or 112 cm.
If you use a 35mm lens, you can use the same rule but multply the DOF by two. Thus, at 2 meters, f/2.8, the DOF would be 28*2 = 56 cm.
Hope that helps.
Very helpful!
I never thought of the DOF as something I'd want to measure, but now I can see how this info may come in handy sometimes.
Many thanks!
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