« on: December 18, 2014, 08:19:14 PM »
I'd like to see someone post a close up of the bottom of the foot. The main 1/4-20 threaded hole is meant to support the lens. The hole in front is used just to keep it from twisting with a second screw. I've not seen this foot up close but in previous builds that front hole was for a second screw to prevent twisting only.
What 'previous builds' are you talking about? The image above doesn't show the hole in front as threaded, which means it's not for a screw. Rather, it looks like a smooth hole for the anti-twist pin found on camcorder/video tripod heads/plates. The EOS M EF Mount Adapter has a similar base on it's tripod foot:
Here's a camcorder plate (the RRS B26 which I use on my EF Mount Adapter and on my Vixia HF M41) that attaches to it:
Obviously, a standard plate without that anti-twist pin would attach as well. But, you can't just 'add a screw', the plate would have to have the pin. Most camcorder plates, and all of the Arca Swiss-type ones I know of, are short (too short for the 100-400 foot if you want freedom to balance it). The only long camcorder plate I've run across is by Manfrotto, and it's a proprietary design for one of their proprietary clamp styles.