t some point I will try the 1.4x version, because I believe that will preserve more of the remarkable IQ of the lens itself.

I had the converter/lens combo mounted on a Leica SL2-S; this is a camera with reasonably good autofocus, though it doesn't compare to the Canon 1Dx I sold a year or two back. It was, in this application, pretty good at nailing focus, but not really quick enough to be a good 'action shot' combo. Still, the camera to lens communication was fine, and the EXIF data correctly identified the combo.

My initial concern about the loss of aperture was not well-founded; I created user profile which set the minimum shutter speed to 1/200 and allowed the ISO to float up to 6400 (which in the SL2-S is astonishingly noiseless), and simply never worried about aperture except to manipulate depth of field.

I was curious, too, to find out how the lens' macro capabilities would work with the converter. This, too, was a pleasant surprise -- essentially, it bought me a little distance from the subject without, as far as I could tell, much altering the power of the macro.

However... All of the images showed a lack of ultimate sharpness which, as I noted, is an inevitable consequence of adding a teleconverter. For this reason, I decided not to add the thing to my arsenal. In the end, I'm somewhat torn between "Okay" and "Good" but, on balance, opted for the more middle-of-the-road assessment.

It seems probable that, once I've finished absorbing the substantial hit from the SL2-S (!), I'll consider the Sigma 100-400 zoom. With any luck, Lensrentals will have acquired one of those by the time I'm ready to think about it! Read LessRead less about There is, of course, an inevitable