oh! thats nice. 70-200 2.8L is a cool toy to play (I have an intention of getting it for street photo, sooner or later) -- it provided you awesome captures. 50mm lens is enough for mushroom photos most of the time (unless they are tiny and you need macro).
cheers!
at that time I did not have 50 mm. for product photography, I used a 70-200 with macro rings. Now I have a macro EF 100 2.8 L.But I have not yet had time to test it on the shooting of mushrooms. I usually go to the forest to pick mushrooms, I rarely take a camera. I take pictures on my phone if I'm in the mood