Originally posted by pschlute The angle of view you are quoting for the Pentax 150-450 is for a FF camera. On an aps-c camera like the K3, the angle will be similar to the Nikkor.
Exactly. And I do not think this situation is about a difference in angle of view spec which is or should be done in lab conditions at infinity focus, to determine any difference between lenses. Pop Photo provides an actual measured focal length of a lens they test, compared to the FL the manufacturer rates it as. Often, the finding is less than claimed. An 85mm lens might prove to be an actual 82mm or even 78mm- there is some degree off of what is claimed that is allowable. For instance, the Pentax DA 70mm Limited, as I recall, tested as around 65mm. The FA 77mm Limited, I definitely recall, tested virtually right on.
The same lab could measure the degree of change in a lens that changes angle of view, while maintaining the same FL, at various distances other than infinity- "focus breathing".