gasstro Loc: Indiana

I had the collar mentioned via eBay. It worked fine for a fraction of the cost.
I don't know about long tern reliability as I no longer have that lens.

Good luck!

dwmoar Loc: Oregon, Willamette Valley

Have you thought of using something like this. A possible solution.

https://www.ebay.com/itm/Camera-Telephoto-Lens-Tripod-Holder-Bracket-Support-QR-Plate-Adapter-Adjustable/202431310090?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

newk

Thank you everyone for some very useful alternatives. I appreciate the help:-)

amfoto1 Loc: San Jose, Calif. USA

At $130 the Tamron tripod ring is a reasonably good value. They have incorporated an Arca-Swiss compatible dovetail into the design, which saves having to buy and install a separate lens plate ($30-$40 typically). I'm not aware of anyone else making tripod rings for that lens.

amfoto1 Loc: San Jose, Calif. USA

There are a number of third party alternatives to the most commonly used Canon OEM tripod rings. It depends a lot upon what lens you have, how much choice you'll have.

AVOID the really cheap (~@25) PLASTIC rings. They break and there's good chance you'll end up with a broken camera and lens.

There are third party metal rings (~$40-$50) that seem better. I've heard both good an bad about them.

Personally I've ONLY used the Canon rings on my Canon lenses. If the price for them new is more than you want to pay, look for used ones various places.

Many of the Canon tripod rings are shared by multiple lenses:

- Tripod Ring A and A II ("W" off-white) are optional and sold separately for use on the EF 70-200mm f/4L USM, EF 70-200mm f/4L IS USM lenses. It is also used on and included with the EF 400mm f/5.6L USM lens.

- Tripod Ring A II ("B", black) is optional and sold separately for use on the EF 200mm f/2.8L II USM lens. Other than color, it appears the same.

- Tripod Ring A II ("WII" brighter white), optional and sold separately, is for the EF 70-200mm f/4L IS USM II lens.

All the Ring A appear to be interchangeable, other than the color match the lens. Ring A loosens and is hinged to swing open to be installed on or removed from the lens. The lens doesn't need to be removed from the camera to install or remove this ring. Fitment is critical with this ring because there is limited clamping force allowed with the screw knob. The limit is probably to prevent overtightening that might damage the "hinge" used in this ring.

- Tripod Ring B ("B" black version) is optional and sold separately for use on the EF 100mm f/2.8 USM macro (not the L/IS macro). It is included with the EF 180mm f/3.5L USM macro and MP-E 65mm f/2.8 macro lenses.

- Tripod Ring B ("W" off-white version) is included with used EF 300mm f/4L IS USM, EF 70-200mm f/2.8L USM, original EF 70-200mm f/2.8L IS USM lenses and the EF 100-400mm L IS USM (original push/pull zoom version).

- Tripod Ring B II (brighter white) is for use with the newer EF 70-200mm f/2.8L II and III lenses.

All the Ring B appear to be interchangeable, other than color to match the lens. This is a split-ring design. It doesn't swing open, so to remove or install it the lens needs to be removed from the camera, the ring needs to be loosened and then rotated to a particular position to slide off the rear of the lens. This design has stronger clamping force that works well with the heavier lenses it fits.

- Tripod Ring C (off-white) is optional and sold separately for use on EF 28-300mm f/3.5-5.6L IS USM and EF 70-300mm f/4-5.5L IS USM lenses. It's a hinged design (like Ring A).

- Tripod Ring D (black) is optional and sold separately for use on the EF 100mm f/2.8L IS USM macro lens. It's a split-ring design (like Ring B).

I believe all the other Canon lenses that use them come with their own unique tripod mounting ring. There may be some limited interchangeability, but I've never had any reason to look into it.

There are a some high quality third party tripod rings, such as those offered by Kirk Photo... but they're more expensive than the OEM rings.

I haven't tried, but might consider metal third party rings by Vello or similar sold by reputable retailers such as Adorama, B&H, etc.

KEH, B&H and Adorama all often have used OEM rings. I've bought used OEM rings off eBay or Amazon, but that takes some care to be sure it's not a cheap, low quality, poor fitting knock-off.

amfoto1 Loc: San Jose, Calif. USA

EDIT: I just saw Gene51 and MTshooter's replies regarding the iShoot ring for the Tamron 100-400mm. That looks like a good alternative at a very reasonable price.

Captkirk Loc: Masterton, Wairarapa, New Zealand

Bought one of these for my Tamron 100-400. Works fine and is a fraction of the Tamron price.
https://www.amazon.co.uk/iShoot-100-400mm-Bracket-Bottom-Compatible-ARCA-SWISS/dp/B07HVSHQ74