One of the features I like in the newer builds is the primitive follow focus using the arrow keys. It's especially nice with the magic zoom. However, I'm thinking about buying a viewfinder that attaches to the lcd screen. This will block the lcd sensor. How will this effect the follow focus? Will it then be impossible to use this feature once I affix the frame to the lcd on my t2i? Are there any workarounds for this? Do others use a viewfinder that blocks the lcd sensor and what should I consider in regard to ML?
