Quote Originally Posted by Daniel Browning


The 17-55 on 50D is equivalent to a 28-90 f/4.5 on full frame.
The 24-70 on 50D is equivalent to a 38-110 f/4.5 on full frame.
Going from 28mm to 38mm is very different. And going from 38mm to 24mm is even more different.
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<div><span style="font-size: small;"]I found this insteresting...

The difference in focal length at the short end (17mm vs. 24mm) is only 7mm but the difference in FOV is about 18 degrees.
The difference in focal length at the long end (55mm vs. 70mm) is 15mm but the difference in FOV is under 6 degrees.</div>