A full day of decent weather gave me a chance to fully test the 1.4X teleconverter on the 100-400mm GM lens, known targets in the morning and critters in the afternoon. The short conclusion is that the great IQ of the lens takes a significant hit with the teleconverter attached. I don’t remember it being this un-good with my previous copy.
The other thing is that ISO at f/8 on the Sony seemed just as high as with the RF 100-400mm/1.4X f/11 combo on the R5, which clearly outperforms the Sony combo. A limiting factor with the Sony setup is the AA filter on the a7 IV. The other thing is that I’ve had to resort to using C1 Express for Sony on Mac, and it doesn’t render with the same sharpness I see when viewing magnified images through the EVF of the camera.
Time to see how Raw Power on ipad renders the files shortly, but I already know it won’t help a lot. Viewing images through the EVF, substantial loss of contrast was obvious on some shots. Stopping down didn’t help at all. And the lost contrast can’t be PP’d back in. Looks like deployment will be just the bare lens going forward.
And, with some irony, I do recall that my first copy of the lens was MIJ, while the current one is china-made. Don’t even have the stomach to check whether it’s the same with the extender . . .