The most common problem - DoF


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Apr 9, 2009
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Most relatively new to photography having focusing issues seem to lack a good understanding of Depth of field.

Depth of field, or DoF, determines a range of distances from your camera that will be have acceptably sharp focus.

Several factors determine that range of distances from the camera. The range can be very shallow, less than an inch, so the background is very blurred, but the foreground is also blurred. Or the DoF can be quite deep, like miles instead of inches.

Here is a very good tutorial - Understanding Depth of Field in Photography and a couple of illustrations I have made:


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nice! Hopefully that will make it a bit more clear to those that need it.
Thank you.. Your visual helps a lot!! :D
aahhh...this is what I was going for, this helps tremendously.
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Is that chart based on 35mm focal lengths? Or, cropped lengths, or there abouts?
That top one shows it as 50 mm focal length. The middle one shows as 24 mm focal length. The bottom one shows for 24, 50, and 70 mm. The human figures are not shown to the scale of the focal lengths.
I saw that, and assumed that meant 35mm focal lengths, but you know what they say about assuming!

Thought between the two graphs it might be helpful for my beginners.
I plugged the numbers into a DOF calculator for an APS-C sensor DSLR, and the numbers seemed to match the charts.
Thank you Keith for the visual. Bookmarked the URL.
Hey - need some clarification...

so I'm using this online DOF calculator...

Online Depth of Field Calculator

it mentions "Use the actual focal length of the lens for depth of field calculations. The calculator will automatically adjust for any "focal length multiplier" or "field of view crop" for the selected camera."

What does it mean by actual focal length? In the picture next to it on an 18-55 it has 55 circled. Does that mean I will use the 55 no matter what focal length i'm using?

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