70-200 2.8 + stacked converters

Just recently got the 1.4x and 2x canon teleconverters to use on my 70-200L 2.8 IS. Just for the fun I stacked the 2x and the 1.4x at the same time. Minimum aperture was still showing as 5.6 and autofocus was still working.

With these 2 stacked is it really 5.6 ? I would guess the loss of quality would mean that it isn't really worth doing.

cheers
Ali

Not recommended as it tends to hunt for focus. A LOT.

No, it's really f/8. Both converters don't report when you stack.

Like above, IQ is bad like this. You'll get a better image cropping with just the 2x converter.

JohnC

So if you took the settings as given in AV you would also be underexposing as the camera would think you were at f5.6 when really you were at f8?

cheers
Ali

Don't know the answer to that one. I've only stacked a couple times, and never happy with the results.

alistairksmith wrote in post #3635875
So if you took the settings as given in AV you would also be underexposing as the camera would think you were at f5.6 when really you were at f8?

cheers
Ali

Should expose ok no matter what is being reported to the Camera because exposure is calculated by what it is seeing throught the Lens (TTL).

Give bad results... Works oke on Moon shots!