Canon Community

I bought my Canon 5D Mark IV in 2017; it's been an awesome camera.  I have seven lenses:Canon 50mm f/1.4, Canon 28-300mm L, Canon 100mm f/2.8 Macro, Tamron 15-30mm f/2.8 G2, Tamron 24-70mm f/2.8 G2, Tamron 70-200mm f/2.8 G2, and a Tamron 150-600mm G2...

I can adjust all of the settings on the 600EX-RT from my 70D but not from my 5D Mark IV; says it isn't compatible.  I've spent the better part of an hour searching online to verify that (I'm guessing that the 600EX II RT does but not my model).  I'm ...