russbecker wrote in post #18757447
Eh, I don't know about that. Depends on the quality of the light, and, whether you have good glass like the 100-400 Mk2.
Even an entry-level 75-300mm zoom, if you're using the whole frame and then making a small web image from it.
You have to remember these web images are seriously downsampled. First one is only ISO 500, second is ISO 1000. Depends on how much frame-filling occurred on the original RAW image. Hard to say without a side-to-side comparison.
A/B comparisons are not "real world usage". "Real world usage" requires mysterious missing information or lack of normalization, apparently. 
Almost any image that looks like an acuity-less blur displayed at a 4 foot diagonal can become a gem of sharpness with downsampling to a 0.5MP 8-inch web image, and maybe even a 1.44MP 14-inch web image.
Nearest Neighbor makes images the sharpest (with lots of potential aliasing, which works as a proxy for detail for many people), but increases image-level noise the most, especially in the bokeh. Binning (2x2, 3x3, etc) is the second sharpest (weaker aliasing), and doesn't increase image-level noise.