Given the high ISO capabilities of this camera will this change the need to use the heavier glass? I'm specifically thinking of the 300 2.8/500 4.0/ 600 4.0. Other than the OOF background, which most times can be achieved in PS what is the gain if you can dial up the ISO to attain a shutter speed of 1000+? What does this do for IS/VR/HSM technology? Will it be needed?
I think it remains to be seen if the noise of the 1D4 is really a stop better. If so, it would help in low light to be able to increase the ISO without adding too much noise or for birds in flight. Personally, I don't foresee a difference as far as the use of lenses is concerned. It just gives you 20% more pixels on the subject.
I don't think it's going to change much. AF is very dependent on the maximum aperture of the lens. The 1-series bodies will AF with an aperture as small as f/8. A 500 f/4 and a 600 f/4 will both AF with a 2x, and the 800 f/5.6 will AF with a 1.4x. Smaller lenses with smaller maximum apertures won't give you that kind of reach.
Hi Charlie,
I agree that 1D Mark IV appears to be a Game changer.
However, not the way you view it. I have been in situations where I have to keep the 400 f2.8 IS aside and just watch the scene unfolding before me. The high ISOs of 1D Mark IV would be of help in recording those situations. I guess ISO 3200 would be good. It would be fantastic if I find ISO 6400 can be used (non-web applications).