Note: This post was copied from the topic "What did you learn Today?" in Learning Photography Forum as it seemed more of a bloggy idea.
This may be common knowledge, but something my film camera provided better info than the D3200. So, continuing to deepen my grasp of the way DOF works and perhaps come up with an easier way for my mind to see how DOF changes and determine what aperture to use to gain a desired effect.
Reading the Cambridge in Color website DOF article, it occurred to me that one could use the size of the subject to determine aperture and did not necessarily need to know the distance. This works because DOF remains fairly constant at different focal lengths provided the subject fills the same percentage of the view. So, a squirrel inside the DOF at 200mm will remain inside the DOF at 100mm or 75mm provided we move toward the squirrel and adjust the view to same we had at 200mm. There are exceptions. More at Understanding Depth of Field in Photography
To reinforce this in my mind, me and Chupa went out to play. Each of the three shots are at different focal lengths, but framed close to the same Chupa-size, keeping aperture at f/11 and the DOF appears to be pretty close in each. The application in my mind I can learn to relate subject size to an aperture (Chupa-size is an f/11) that keeps the subject inside the DOF easier than remembering distance + focal length + desired DOF = aperture (Chupa is 10' away at 200mm and I need 3" behind him, so the table says X).
This may be common knowledge, but something my film camera provided better info than the D3200. So, continuing to deepen my grasp of the way DOF works and perhaps come up with an easier way for my mind to see how DOF changes and determine what aperture to use to gain a desired effect.
Reading the Cambridge in Color website DOF article, it occurred to me that one could use the size of the subject to determine aperture and did not necessarily need to know the distance. This works because DOF remains fairly constant at different focal lengths provided the subject fills the same percentage of the view. So, a squirrel inside the DOF at 200mm will remain inside the DOF at 100mm or 75mm provided we move toward the squirrel and adjust the view to same we had at 200mm. There are exceptions. More at Understanding Depth of Field in Photography
To reinforce this in my mind, me and Chupa went out to play. Each of the three shots are at different focal lengths, but framed close to the same Chupa-size, keeping aperture at f/11 and the DOF appears to be pretty close in each. The application in my mind I can learn to relate subject size to an aperture (Chupa-size is an f/11) that keeps the subject inside the DOF easier than remembering distance + focal length + desired DOF = aperture (Chupa is 10' away at 200mm and I need 3" behind him, so the table says X).
| Model | NIKON D3200 |
| Capture Date | 2014:05:20 12:42:43 |
| Shutter Speed | 1/500 |
| Aperture | f/11.0 |
| ISO | 1600 |
| Exposure Comp. | 0.00EV |
| Focal length | 200.00mm |
| Model | NIKON D3200 |
| Capture Date | 2014:05:20 12:43:06 |
| Shutter Speed | 1/1250 |
| Aperture | f/11.0 |
| ISO | 1600 |
| Exposure Comp. | 0.00EV |
| Focal length | 120.00mm |
| Model | NIKON D3200 |
| Capture Date | 2014:05:20 12:43:39 |
| Shutter Speed | 1/1250 |
| Aperture | f/11.0 |
| ISO | 1600 |
| Exposure Comp. | 0.00EV |
| Focal length | 65.00mm |
