iShoot Metal Lens Replacement Foot Camera Lens Collar Base Tripod Mount Ring Support Adapter Stand for Sigma 500mm F4 DG OS HSM Sports Lens Build in Arca-Swiss Type Quick Release Plate

Well built. Quality finish. Comfortable when holding this heavy lens. A nice improvement to an already great lens.

The original Arca foot on my Sigma 60-600mm DG DN OS Sports lens is not very long and is actually not long enough to balance my setup on my gimbal head. I took a chance with this iShoot replacement foot, not sure if it would fit my lens. It does!.It is a very well-made item and certainly long enough for my gimbal to balance, and much better for carrying the hefty camera/lens assembly. It’s not quite as rounded at the edges as needed to be fully comfortable on the fingers but it’s acceptable. A small chamfer would have been good but admittedly tricky to form. The Arca grooves fit the Arca mount on my tripod and my gimbal head just fine..It’s a shame but the quality of this product is somewhat detracted from when you consider the screws. My photo shows the original Sigma screw and the iShoot one, which is much shorter. The iShoot foot is designed with a common length of screw hole. The Sigma has a longer hole at the front end. Using the short iShoot screws in all four locations didn’t look very good for a strong joint. I found that the best combination was to use the longer Sigma screws at the rear (camera end) pair of holes (since that was basically the same geometry as the Sigma foot) and the shorter iShoot screws at the front. If I used the Sigma screws at the front of the iShoot foot, they were too long and bottomed out in the lens’ threads, just. The iShoot screws were long enough at the front with a more than adequate engagement ( >2 x screw dia).What iShoot have missed is that the Sigma design allows the plain shank of the screw to engage with a plain bore in the lens before the thread starts. This helps to locate the foot on the lens pad and doesn’t put the screw thread in shear at the joint. Note there is no plain shank on the iShoot screw, whereas there is on the Sigma screw. That’s why I wanted to use at least a pair of Sigma screws to keep that design feature.Good job I’m an engineer and check these things!.Overall, I’m pleased with the purchase. $30 is maybe a little high IMHO, but camera gear is typically expensive and $30 on a $2000 lens is not that bad a deal. This iShoot extended Arca foot does the job, looks the part, and almost looks ex-factory.