iShootLens Collar Tripod Mount Ring Compatible with Canon EF-E Sigma MC-11 Mount Converter Lens Adapter Ring, Lens Support Holder Bracket Bottom is Arca-Swiss Fit Quick Release Plate Dovetail Groove

I bought this collar for my Sigma 70mm 2.8 macro art lens. I needed this collar because the lens plus the MC-11 on my A7c was too front heavy – especially when mounted face-down on a copy stand (for negative scanning). This product fit the MC-11 ok and solved my problem. The Sigma macro is not a big lens though. There is a tiny bit of misalignment when the collar is fully tightened (see pic). It's possible to get it a little straighter by applying corrective pressure while tightening the collar. I use a bubble level on the camera itself so not a big deal but still annoying. There really isn't much else on offer so I'm glad this exists. The MC-11 doesn't have much room for a collar so it probably was a pain to design.

縦構図でMC11に取り付けると、AF｜MF切り替えスイッチが触れなくなります。

Sigma failed to provide an Arca-Swiss type foot on their MC-11 Sony to Canon EF mount adapter (unlike the Metabones adapter). This is the only good tripod ring / lens collar choice I found to provide a balanced mounting for the MC-11 on a tripod.It has its limitations. Because the limited width of the bearing surface available on the MC-11, I would not advise using this collar on lenses over about 200mm or 1,200g. At that point hopefully the lens has its own collar.Since the MC-11 has a lens release slider and a cover over the firmware upgrade port, a lens collar must have cutouts to accommodate these protrusions beyond the MC-11’s diameter. This prevents you from rotating the camera with attached MC-11+ lens between landscape and portrait orientation as permitted on a lens designed for a lens collar. With this lens collar you must detach the collar+lens from the camera, loosen the collar, remove the collar, rotate it 90 degrees, slide the collar back on, re-tighten the collar’s clamp, and re-attach the collar+lens to the camera.The only way to design a collar for the MC-11 that avoids this process would be a hinge in the collar that allows opening up the collar to rotate the camera with attached MC-11+lens. Some Canon lens collars / tripod rings are hinged in this manner.You should practice sliding the collar as far as possible on to the MC-11 before tightening the clamping bolt. If the collar is not pushed on firmly, it will not firmly grip the MC-11 or may slightly protrude back, interfering with mounting the MC-11 to the camera.Finally, I suggest marking the collar with some tape or paint where to align it with the white dot on the Sony body’s mount. The collar covers the white dot on the MC-11, making it difficult to align the MC-11 with the white dot on the camera’s lens mount.All in all, I would buy it again but wish Sigma had put an A-S foot on the MC-11 in the first place.

sigma mc-11用の三脚台を注文しましたがeos-R用が届き、返品して、再度購入いたしました。が、2度目も同じ商品でした。返品商品中ですが、3度もまたかな？とおもうと、購入をためらいます。商品は、欲しいのですが。