OP: Hi guys, I just upgraded from Canon APS-C to Canon R6. Would my 24-105 have a wider FOV at 24mm than my 18-55 at 18 on the crop camera?
B: Yes, 18mm is equivalent to 28.8 on FF (Canon’s crop factor is 1.6), so 24mm would be wider.
C: Use the online calculator at www.wecannotmultiply.com.
D: Yes, 18mm on Canon crop is equivalent to 28.8 on FF.
E: The FL does not change magically when you change the sensor.
G: FOV is expressed in angles, not mm. Take inverse tan of the cosine of the inverse cosine of the frame width over 2 over the FL in each case and compare them. You get xyz for the crop AOV vs. abc for the FF one, so indeed, wider.
D: But this is for the horizontal FOV only. You need to compare the diagonal and the vertical ones as well.
C: Canon’s crop factor is not exactly 1.6. The frame height is 14.8mm, see this: en.m.wikipedia.org/wiki/Crop_factor. It needs to be 15mm for a crop factor of 1.6. It is actually 24/14.8 = 1.62162162162.
D: But Canon FF is not 24x36 exactly either. The 6D has sensor size of 35.8 x 23.9mm.
E: That’s an exception. The OP bought the R6, not the 6D.
F: You are both wrong. The sensor size doesn’t matter. Some border pixels are cropped out in conversion. What matters is the remaining image which is formed by the effective pixels. In particular, sensors with smaller pixels will provide a wider FOV.
E: You are all ignoring distortion. Distortion correction limits the FOV.
F: It doesn’t. FL is stated AFTER distortion correction.
E: The stated FL is always approximate anyway.
K: The AOV changes with the distance to the subject. You are all wrong.
OP: I take it that the answer is YES.
