Panasonic Lumix S Pro 70-200mm f/2.8 (vs f/4) Review

Which is the better lens? Panasonic Lumix S Pro 70-200 f/2.8 or the Panasonic Lumix S Pro 70-200 f/4? I'll compare these two lenses in this review. My Instagram:   / photo_by_richard   My Facebook:   / photobyrichard   Intro Music - Special Thanks to LYL Music   / itslylmusic