I ran some rough tests on the Sony FE 24-105 f/4 G at 24mm, 50mm and 105mm using a basic lens chart with an A7RII shooting RAW. Wow, what a lens! It out-performs pretty much every 35mm film zoom I've ever owned, and many of the primes, especially wide angles.
This lens does exhibit some light and resolution falloff in the corners wide open, but was cleared up by f/5.6-f/8. Except strangely at 24mm, light falloff diminished at f/5.6, returned in the far corners at f/8, then disappeared again at f/11. Through the range of focal-lengths, I found the sweet spot to be f/5.6 to f/11. At f/16, diffraction is held back amazingly well, and though f/22 shows some diffraction degradation on the chart images, in real world shots it can be tolerable due to the outstanding sharpness and contrast characteristics of this lens.
I don't know how much correction was done in the camera, but CA is nil. And I didn't see any noticeable barrel or pincushion distortion.
Reviews I'd read suggested the lens was good, so once I got it, it was immediately pressed into service shooting products before I'd tested it. And I was astounded. Images held together as I progressively stopped down to catch details through depth-of-field. Shooting at around 75mm, working as high as f/18, even into f/20, real-world details were captured without apparent diffraction and post-production sharpening wasn't necessary. And the lens focuses very close, making a lens change unnecessary for smaller items.
Though I'm mostly a tripod guy, it performed very well while playing around with it hand-held. It didn't have a problem focusing in home-level lighting. The stabilization worked well, though I'll admit I have the ISO turned way up when snap-shooting. But I do like its switches for stabilization and focus so I don't have to hunt around or remember where I programmed which control, when I put it back on the tripod.
Can't really say anything bad about this lens. I'm used to manual focus lenses, or little micro four-thirds cameras, so it seems big to me, but this lens is full-format, and with all those gears and motors inside for stability and focusing, that's understandable. And it takes a large, telephoto-sized filter, but 77mm is not crazy-big and at least the lens doesn't require some oddball internal filter. So even those factors are okay.
All in all, I'm extremely happy with the Sony FE 24-105 F/4 and from what I've experienced with it so far, it could just be one of those lenses that becomes legendary.
