Let me demonstrate one of the best qualities of a good lens or glass, as we sometime refer to that integral part of the probably most important photographic equipment.
The DoF, or the Depth of Field, or simply said the part of the photo "on focus", depends on many parameters.
- The camera sensor size
- The focal length of the lens (the mm)
- The distance to the subject
- The aperture used
Yes, there is math and formula in and about that and yes, there are plenty of free and paid apps on all the mobile stores to give you the exact numbers.
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