Alex_B
No longer a newbie, moving up!
- Joined
- Aug 30, 2006
- Messages
- 14,491
- Reaction score
- 206
- Location
- Europe 67.51°N
- Can others edit my Photos
- Photos NOT OK to edit
No it means for a DX sensor a 17 is a 17 and not some differend adjusted for "crop factor" focal length. Otherwise why bother making DX formatted lenses.
a 17mm is always a 17mm, no matter on what sort of sensor or film you use it on. but the angle of view is small on a crop sensor.
DX lenses can just be smaller and lighter, and cheaper to produce, since they can survive with a smaller image circle.
A 17mm DX lens on a DX sensor gives around 79 degrees angle of view. on a full frame sensor, you would get the same angle of view of 79 degrees, if the focal length was 1.5x17mm. This is the meaning of the so called crop factor.