Free advice and it may be worth what you paid for it. : ) I've had the EF version and have the RF version. As you know the are incredibly lightweight. So you don't need the collar unless you need to rotate the camera, which of course is very helpful. But you certainly don't need it for support as it's not going to stress the bayonet mount on the body at all. It's not nearly as nice looking, but Vello has one for $50.
Thanks! I use the tripod ring for camera rotation in ‘fixed’ setups, macro rail and/or the twin light when the heads are attached to the lens plate with Wimberly F-2 brackets. I have L-plates (modular for the R3 and R8, but if I’m bringing a tripod I attach the upright bracket).
If I get the RF 100, I’ll look at the Vello ring. But I doubt I’ll get the lens, the EF does great.
Other point: the Control Ring is very helpful. I would argue it's worth the investment to have that feature. I always recommend the EF to RF adapter WITH the Control Ring when friends ask which one to buy. Being able to assign whatever custom function to that ring could make using the lens more pleasant, more productive. Change ISO settings, color balance, whatever you assign to it. I would be really cool if you could assign focus stacking to the Control Ring to shift focus by a set number of millimeters per click, but that's just me wishing for a feature that I don't think is assignable.
I have the control ring set to ISO, and honestly that’s usually on Auto. My macro shooting typically doesn’t require rapid changes. I don’t have the control ring adapter, I do have the vanilla one, the drop-in filter version (with CPL and vND which are very useful behind the TS-E 17 and EF 11-24/4, and the clear insert if no filter is needed). I also have a 3rd party adapter (Commlite) that I ground down to stack RF extenders behind EF extenders with my EF 600/4 II. Three adapters is probably enough.
And lastly, its max magnification is 1.4X which might be another justification to make the swap.
When I need higher than 1x, I use my MP-E 65. That goes to 10x with the 2xIII TC, and if I need even more for some reason, I have an EF mount adapter setup as an eyepiece adapter for my Zeiss Stemi DV4 stereomicroscope that covers 8-32x. Outside of the hobby realm, I have microscope systems in the lab up to superresolution (optical microscopy that resolves beyond the Abbe wavelength limitation). So I’ve got all the magnification I need.
