So I am looking for something like this (I am guessing it is attached via HDMI?): but only seem to find stuff like this: http://www.amazon.com/MegaGear-Screen-Viewfinder-Digital-Cameras/dp/B00AS9119C The purpose is to be able to focus while shooting video with a Canon 5D Mark III. I need reading glasses and even with them on, I can't see the Canon LCD well enough from really up close to use it to focus. I need something that comes with a diopter adjustment, just like the Canon's own viewfinder does. The Amazon MegaGear thing linked above does not have an eyesight adjustment, and seems cheesy in any event -- you can't be seriously shooting depending on a magnetic attachment not to come loose. The one in the picture at least looks solid, but don't know what it's called, where to find it, etc. I suppose I could just go to B&H and ask, but what fun is that when I have HTF? Thanks, guys! Edit: OK, found something on B&H: http://www.bhphotovideo.com/c/product/736853-REG/Zacuto_Z_FIND_EVF_Z_Finder_EVF.html Suffering price shock - this one appears to be the cheapest one with any decent reviews.