Focal length equivalents
| MFT |
APS‑C |
FF |
MF |
| 12mm |
16mm |
24mm |
30mm |
| 13mm |
18mm |
27mm |
35mm |
| 18mm |
23mm |
35mm |
45mm |
| 20mm |
27mm |
40mm |
50mm |
| 25–27mm |
33–35mm |
50mm |
63mm |
| 42mm |
56mm |
85mm |
105mm |
| 68mm |
90mm |
135mm |
170mm |
Table of relationship between various photographic parameters
ALL OTHER PARAMETERS BEING EQUAL – e.g., effect of focal length assumes that
aperture ratio stays constant, not the physical diameter of the lens!
| dependent ╲ independent |
exposure |
flash exposure |
field of view |
bokeh diameter |
depth of field |
subject motion blur |
camera motion blur |
film grain / quantization noise |
image noise |
resolution |
| focal length (mm) |
|
|
•−1 |
•2 |
•−2 |
• |
• |
|
|
|
| aperture (f∕•) |
•−2 |
•−2 |
|
•−1 |
• |
|
|
|
|
|
| shutter speed (1∕s) |
•−1 |
|
|
|
|
• |
• |
|
|
|
| sensitivity (ISO) |
• |
• |
|
|
|
|
|
|
• |
|
| push processing (ISO) |
• |
• |
|
|
|
|
|
• |
|
|
| sensor size (diag) |
|
|
• |
•−1 |
• |
•−1 |
•−1 |
|
•−2 |
|
| pixel count |
|
|
|
|
|
|
|
|
• |
• |
| cropping (diag) |
|
|
•−1 |
• |
•−1 |
• |
• |
|
|
•−2 |
| scaling |
|
|
|
|
|
|
|
|
• |
• |
| image stabilization |
|
|
|
|
|
|
•−1 |
|
|
|
| ND filter |
•−1 |
•−1 |
|
|
|
|
|
|
|
|
| flash power |
|
• |
|
|
|
|
|
|
|
|