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Tripod head: anti-slip pin & anti-rotation pin explained (1 Viewer)

marcsantacurz

Well-known member
I had someone ask me in a PM about these things, so I thought I would explain it here with a few photos.

Some fluid heads will accept a standard quick release plate called an Arca Swiss (or just Arca at times). These slide through a vice-like clamp that holds them in place. If the clamp is loosened, the plate can slide right through crashing your gear to the ground.

There are two ways to prevent this. One way is to put two small set screws in the plate that prevent it from sliding through. As long as the ends of the plate are outside the head clamp, it works. The second way is with an anti-slip pin on the head, as shown in the 1st photo below on my Sirui VA-5 head. The big red button on the right lowers that pin to release the QR plate.

Some lens and scope feet will have 1 screw hole (usually a 1/4-20 standard camera) or two 1/4-20 or a 1/4-20 plus a small unthreaded hole. The reason to have 2 holes (threaded or unthreaded) is with two the scope cannot rotate and come loose of the tripod head. A common combo is the 1/4-20 thread plus a smaller unthreaded hole. That hole is for the so-called video pin or camcorder pin, as it was introduced for a camcorder mount.

The 2nd photo below is my MM4/60 foot showing two threaded holes (the small 3rd hole is for a set screw). So I could use an arca swiss plate with two 1/4-20 screws or, as shown in the 3rd photo, a Really Right Stuff (RRS) plate with a 1/4-20 plus video pin.

The RRS plate I use is the Really Right Stuff Camcorder Quick Release Plate (B26). It is almost exactly the same length as the MM4's foot.

Why I like this RRS plate is it still has its own 1/4-20 hole in it so I can attach the scope to my Nikon car window mount without removing the RRS plate.

The video pin spacing is standardized, so if you see something with it likely it will work. Usually the 1/4-20 screw goes through a slot in the QR plate, so it can adjust to whatever spacing is needed. QR plates with two screws can also adjust to any spacing. Some QR plates will have a 1/4-20 and

For example, the Manfroto 700RC2 and Benro S4 have a video pin plus 1/4-20 screw. The Sirui VA-5 plate has a single screw, so what I would do with that (if I used it) is to add a 2nd 1/4-20 screw to it.

Marc
 

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marcsantacurz

Well-known member
I got a couple more questions in PM that I will answer here.

What keeps the plate from sliding out of the head clamp? In Photo #1, there is a pin in the middle of the head that sits under the QR plate and keeps it from sliding out if the clamp is released. Some plates will have small set screws at the ends that keep them from sliding across the plate, but that means you need a very long plate to allow for balancing.

What did you mean by "The reason to have 2 holes ... the scope cannot rotate and come loose of the tripod head."? I should have said "off the QR plate" not off the head. The scope attaches to the QR plate, and the plate attaches to the head.

Marc
 

mskb

Well-known member
Hello Marc, thank you so much! Your post and the subsequent comment answered the several questions i had on going about purchasing a head and a plate.
 

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