Long and strong Arca Swiss rail for heavy lens?

Hi,

I currently have a Wimberly foot for my Canon 600mm lens. The lens is Mk 1, which means it's heavy; about 11 lbs. With my 5D Mk III body, the lens balances properly when the rail is mounted to the gimbal head at its farthest end. (This puts the most torque on the rail, but seems to have been working fine for a couple of years.)

I've recently picked up a Canon R6 body which is lighter than the 5DIII. (The only attribute I'm asking about here is related to the camera weight.) With the lighter body, the balance for the gimbal is now thrown off and the rail isn't long enough to get balanced.

I could:

1. Add weight to the body to achieve balance. I already have the EF-RF adapter, which adds a little bit of weight and it moves the camera farther back, which helps. Also, I already have an L-bracket on the body, but I could add some fishing weight into that to make it heavier. Or I could add a battery grip. When using a 600mm lens, I'm already pretty conspicuous and a big battery grip isn't going to make a difference. But for all other shooting situations, I prefer to be smaller and less conspicuous so I'm not preferring the battery grip option.
   
2. Remove the lens hood. The system balances nicely with the hood removed, but I lose the protection for that big glass element up front plus the protection against light hitting the front element and reducing image quality. I definitely don't prefer this option.
   
3. Replace the current rail with a longer one. I'm actually looking for this now, but not finding an option. The current rail is about 6.5" long. A longer rail means even more torque on the rail to support the longer lever moment, so I'd want to make sure that it's a high-quality rail. But I don't know that such a thing even exists.
   
4. Start the balancing game over with a new lens. Not in my budget right now.
   

• Have you seen a reliable, strong and longer (than 6.5") rail?
  
• Have you experienced this balance problem with the newer, lighter bodies?
  
• What is your recommendation?
  

I haven't actually used one or experienced the issue; but, the only, longer plate I can find from anyone resembling a reliable manufacturer is a 200mm (almost 8in)plate from Benro.

Are you using the Wimberly gimbal?

Hi Eric, and thanks for the idea. I totally forgot about it until reading your post, and I actually have a couple longer (8") Arca rails on a slide duplicator that I built.

However, I hesitate on using the rails that I have for two reasons. First, at only 3.2 ounces I wonder if it would be strong enough. Second, the "rails" for long lenses actually have 4 mounting holes at one end, and not the usual 1/4-20 screw (or slot). My lens has those matching 4 screw holes where the original foot was mounted. The Wimberly part that I have is actually called a "replacement foot" and happens to be compatible with Arca Swiss, rather than being a (generic) Arca Swiss rail. It's these little details that are causing me grief.

But the process of taking a picture and posting this question caused me to think a bit deeper on this. How much weight do I need?

I took the L-bracket off for the picture above. But when putting it back on it weighs 2.6 oz. Adding a double-Arca clamp to the bracket and then another one, added another 7.5 oz to the end of the lever. At a total of 3 pieces and 10.1 oz, the system balances out. The randomly added Arca clamps looks pretty random... I'd prefer to have a balanced rig for steady pictures, so maybe I just stay with this...

Regarding the gimbal question, yes it's a Wimberly (I think it's called the "Sidekick".)

dasmith232 wrote in post #19329666
Hi Eric, and thanks for the idea. I totally forgot about it until reading your post, and I actually have a couple longer (8") Arca rails on a slide duplicator that I built.

However, I hesitate on using the rails that I have for two reasons. First, at only 3.2 ounces I wonder if it would be strong enough. Second, the "rails" for long lenses actually have 4 mounting holes at one end, and not the usual 1/4-20 screw (or slot). My lens has those matching 4 screw holes where the original foot was mounted. The Wimberly part that I have is actually called a "replacement foot" and happens to be compatible with Arca Swiss, rather than being a (generic) Arca Swiss rail. It's these little details that are causing me grief.

But the process of taking a picture and posting this question caused me to think a bit deeper on this. How much weight do I need?

I took the L-bracket off for the picture above. But when putting it back on it weighs 2.6 oz. Adding a double-Arca clamp to the bracket and then another one, added another 7.5 oz to the end of the lever. At a total of 3 pieces and 10.1 oz, the system balances out. The randomly added Arca clamps looks pretty random... I'd prefer to have a balanced rig for steady pictures, so maybe I just stay with this...

Regarding the gimbal question, yes it's a Wimberly (I think it's called the "Sidekick".)

Hosted photo: posted by dasmith232 in
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forum: Tripods, Monopods & Other Camera Support

LOL; I mean...adapt and overcome, right? The pic looked like a Sidekick, so I was trying to imagine whether you were trying to balance one or two axes. We're pretty early on in the lifecycle for these bodies, so your situation may well be somewhat at the forefront of folks using the lighter bodies on gimbal setups. May wind up having to stick with this kind of a DIY setup until the system manufacturers catch up Maybe it's time to add that 1.4TC for good measure?

Snydremark wrote in post #19329681
LOL; I mean...adapt and overcome, right? The pic looked like a Sidekick, so I was trying to imagine whether you were trying to balance one or two axes. We're pretty early on in the lifecycle for these bodies, so your situation may well be somewhat at the forefront of folks using the lighter bodies on gimbal setups. May wind up having to stick with this kind of a DIY setup until the system manufacturers catch up Maybe it's time to add that 1.4TC for good measure?

Well, good news: I have both the 1.4 and 2x TCs, and the R series will handle the higher effective f-stops and keep autofocusing!

Thanks again!

There are lots of Chinese plates available, 200mm (8 inch) and longer.
Instead of replacing your foot, you could just add a plate of the same length. Another 6.5 inch plate, bolted underneath, with 4 inches under the existing plate adds 2.5 inch total. So you add a little distance of the centre of the lens to sidekick clamp but it's a strong, simple solution.

If you have tools and happy with some DIY you can easily make something solid.
I have modded several plates: enlarging holes, eg 1/4 to 3/8, countersinking holes etc to adapt plates for specific uses and don't lose any functionality while doing so. I have a small collection of bolts, nuts, washers in 1/4 and 3/8 sizes. A hacksaw, file and vice and I can make anything required.

I can't remember the brand of foot I have for Sigma 500 f4. Low profile replacement. I have a longer plate attaced underneath. It does not need to be strong as there is just some overhang at each end of the replacement foot. I have some screws attaching the long plate to the replacement foot.
I tapped some holes in the replacement foot and shortened some screws so they are flush for a neat job. It's not difficult.

Choderboy wrote in post #19329724
There are lots of Chinese plates available, 200mm (8 inch) and longer.
Instead of replacing your foot, you could just add a plate of the same length. Another 6.5 inch plate, bolted underneath, with 4 inches under the existing plate adds 2.5 inch total. So you add a little distance of the centre of the lens to sidekick clamp but it's a strong, simple solution....

Thanks for the suggestions, Dave. The idea of bolting another plate to the existing one may work. I'll play with it some more.