New Oly 100-400 at the zoo

My wife has the 75-300 and I think it's pretty good for a budget lens. Looking at images on-screen at normal resolution, I can't tell any sharpness difference between it and the 100-400. However, I haven't done any serious testing or pixel peeping to look for differences either because it wouldn't serve any purpose for me.

BTW, Oly's own MTF charts indicate that the 100-400 is a bit sharper (see below). If ultimate sharpness in a MFT lens in this focal range is really that important, there is always the 300 f/4 for about $1000 more (but lacking the convenience of a zoom) or the 150-400 f/4.5 for five times as much. For me, excellent sharpness is far more important than ultimate sharpness and the 100-400 delivers. It is plenty sharp for its price and capability.

The 100-400 brings a lot more to the table than the 75-300: longer native reach, ability to use teleconverters for even more reach, better build, weather sealing, image stabilization (non sync), slightly faster focusing (my impression), a focus limiter, and a tripod collar. The 75-300 wins for weight and price, but it's really a false comparison because of the differences I just pointed out.

So, rather than being disappointed that the 100-400 is not significantly sharper than the 75-300, I am thrilled by its excellent sharpness and all the other features and benefits.  The 75-300 and the 100-400 are very different lenses serving very different markets.

Oly 75-300 @ 75 mm

Oly 75-300 @ 300 mm

Oly 100-400 @ 100 mm & 400 mm