wendellt wrote:at that focal length you can adjust shutter to at least 1/50 get more exposure hence less noise
Up to a point. The "reciprocal rule" (just a rule of thumb really) actually refers to 35mm-equivalent focal lengths, so if you were to stick to the "rule" you would say that you could get away with 1/(50*1.5) => 1/75s. Call it 1/80s, and that's only 1/3rd of a stop more exposure than the above shot...
Also, different people with different techniques and skills can hold at different shutter speeds, but none of this can help with a subject that's moving (consider the moving hands of the gorilla in that shot). This is the same as VR/IS not helping with most moving subjects.
It's true that increasing the exposure will reduce the apparent noise levels, and this is one of the reasons that people pay for fast lenses that are still sharp at wide apertures.
But I think another important factor here is that this particular shot looks like a crop from the original. Are we looking at a 100% crop? Because the standards of what level of noise is acceptable at print size are going to be different to what is acceptable at 100% viewing!
Given the apparent chromatic aberration I'm guessing that the lack of sharpness in this shot isn't just because it's noisy or due to movement. Critical focussing and "low" lens quality are also important to the perceived quality: improve these and the shot will look better (of course, make them perfect and the image noise may become more obvious
).
Again these issues are usually less apparent when viewing the whole image.