Alireza202
Equivalent focal lengths in terms of DOF between different formats
In a photo I posted some months ago, I compared the depth of field (DOF) between APS-C and Full Frame (FF) using the same field of view and aperture. In the above table, which is published by Zeiss, we can see how the same aperture on two different formats results in different DOF.
Here is how we read this table. In the third row, we have the name of the formats, and the rows below are the f-numbers. Here is an example: F1.4 on APS-C format is equivalent to F2.0 on FF, F3.4 on 6x4.5, and F4.8 on 6x7, in terms of DOF. Another example: The aperture F2.0 on a 4/3" camera is equivalent to F4.0 on a FF camera. This means that the Olympus 35-100mm F2.0 is equivalent to a Canon 70-200mm F4.0, in terms of depth of field.
That's why in Large Format photography, you have to stop down to crazy apertures like F32.0 or F64.0 to get everything in focus!
We can also compare the DOF between smaller formats as well. For example, Canon G11 which is a high-end compact camera, has a sensor format of 1/1.7". So F3.4 on G11 is equivalent to F16 on FF, in terms of DOF. That's why you cannot pull out shallow DOF from compact cameras!
Note that this comparison is correct, if you keep the same field of view, same focus distance, use equivalent focal lengths and show/print the photo with the same size.
But remember, in terms of gathering light, aka exposure, F4.0 on any format is F4.0, meaning that the exposure does not depend on the format.
Update: This is the link to the PDF file.
Equivalent focal lengths in terms of DOF between different formats
In a photo I posted some months ago, I compared the depth of field (DOF) between APS-C and Full Frame (FF) using the same field of view and aperture. In the above table, which is published by Zeiss, we can see how the same aperture on two different formats results in different DOF.
Here is how we read this table. In the third row, we have the name of the formats, and the rows below are the f-numbers. Here is an example: F1.4 on APS-C format is equivalent to F2.0 on FF, F3.4 on 6x4.5, and F4.8 on 6x7, in terms of DOF. Another example: The aperture F2.0 on a 4/3" camera is equivalent to F4.0 on a FF camera. This means that the Olympus 35-100mm F2.0 is equivalent to a Canon 70-200mm F4.0, in terms of depth of field.
That's why in Large Format photography, you have to stop down to crazy apertures like F32.0 or F64.0 to get everything in focus!
We can also compare the DOF between smaller formats as well. For example, Canon G11 which is a high-end compact camera, has a sensor format of 1/1.7". So F3.4 on G11 is equivalent to F16 on FF, in terms of DOF. That's why you cannot pull out shallow DOF from compact cameras!
Note that this comparison is correct, if you keep the same field of view, same focus distance, use equivalent focal lengths and show/print the photo with the same size.
But remember, in terms of gathering light, aka exposure, F4.0 on any format is F4.0, meaning that the exposure does not depend on the format.
Update: This is the link to the PDF file.