
It was very difficult to decide between Sony 70-200 GM F2.8 and Sony 70-200 F4. When I got my hands on these two lenses (which is impossible when all you have is a spec sheet or a video review) I realized that I had NO WAY to hang a GM lens around my neck. It's just too hard. I could not use a GM lens on a tripod as tripods are not allowed for travel and school events. The 70-200F4 is so much lighter and less painful to hang around your neck or in your hand that it was the obvious choice. Please note that I am not comparing image quality but how it can be used. If a lens is so heavy that I'm afraid to use it, it never gets used.

Canon EF 40mm f/2.8 STM Lens - Fixed Black (6310B002) for US Cameras
76 Review

Canon EOS SLR Camera Lens EF 24-105mm f/4 L IS USM
124 Review

Nikon 50mm f/1.8D Lens: Perfect for Nikon DSLR Cameras!
97 Review

Nikon 35mm f/1.8G Auto Focus Lens for Nikon DSLR Cameras - Black (Model 2183)
125 Review