Re: Canon R7, Ef 100-400 ii and 1.4 Tc Bif Photos. Are these acceptable?
Victor Engel wrote:
Ephemeris wrote:
Victor Engel wrote:
Ephemeris wrote:
davel33 wrote:
"So 1.4 tc doesn't improve iq"
There is NO extender 1.4x or 2.0x that will improve iq.
It only makes the image bigger.
There is a difference
I fell for that same trap.
It could help your AF get an in focus shot?
Or it could hinder, if the focus sensors require a wide aperture to work well.
Becuase of the amount of light? Not sure I quite follow.
It has nothing to do with the amount of light. Cameras using phase detection to focus (see https://en.wikipedia.org/wiki/Autofocus) rely on rays traveling through the lens at some distance from the center. The more accurate sensors require f/2.8, one of the reasons there are so many f/2.8 lenses. Adding a TC, you reduce, possibly, the number of focus sensors available for focusing. because those sensors can't see through the lens. This doesn't apply to contrast detection focusing.
Cameras like R5 and R7 that use dual pixel technology for focusing require a certain minimum aperture. With the recent introduction of several f/11 lenses, I'm guessing it must be slightly smaller than f/11. If I'm right, the dual pixel focusing would not work with one of those lenses plus a TC.
Im not sure that I follow.
Why would using a TC reduce the number of pixels available for focussing? The sensor is still totally illuminated. Why can't they are through my lens?
We use R5s with an EF 100-400ii and 1.4x TC iii. The focus system appears to operate in a very similar fashion with or without the TC.
I'll the amount of light isn't the concern is it the DOF? If so wouldn't that mean that all lenses above say 400mm won't work?
I've probably not understood your thinking but I can assure you this set up does work. I can't comment on the F11 lens but I would expect it also to function.