« on: October 23, 2014, 11:54:52 PM »
To get that crop reach advantage, you need a GREAT lens. A lens like the 100-400 or the Tamron 150-600 is not sharp enough.
I'll challenge anyone to go out with a 1DX or 5DII or III and get a moon shot like this one with a 100-400L.
Nice image, well processed; but not sure I see the point.
It was shot with a 100-400L + 1.4x TC - so you could not even capture that image on a crop camera with the 100-400L alone.
And what's the purpose of a TC? Answer: To compensate for the sensor under sampling the lens. A 1.4x TC can be thought of as shrinking the pixels by 1.4x or as doubling the pixel count, rather than doing anything optically. They are equivalent, and in both cases if the lens isn't resolving the detail, the extra pixels or extra magnification won't help. But it does help as you just said yourself. And you are right.