I really like this shot. Actually it is called gray code named after Frank Gray. And this is indeed a gray code. Notice how only one bit changes for each step.
CircuitR wrote in post #13638087
Wow, I have the Sigma 2x. I didn't realise how much smaller the front element was compared to the Canon. I'm guessing that your going to selling the Sigma.
Thanks for sharing.
Not only the front element is bigger, but the protrusion into the back of the lens is larger diameter too. Both teleconverters will fit Canon lenses that are designed for a TC but the Canon TC won't fit some Sigma lenses that don't have a large enough opening in the back of the lens. My 50-500, for example, fits the Sigma TC fine but not the Canon.