Arca Type QR

[psychonaut]

i just realized that there is Digital-Rebel-Specific Arca-Type plate. i can't quite picture the mechanism of operation of an Arca-Type clamp.

any Arca-Type plate will fit any Arca-Type QR adapter of equal or greater length ???

how exactly does it lock in place ? or does it not lock at all and you just tighten it to the point that it will not move ?

[CyberDyneSystems]

You are correct.. the Arca system is an "open Channel"... allowing adjustment in one axis limited only by the length of the plate used.

However.. once the clamp is tightened .. it IS locked .. at least as solidly as any other QR system out there.. probably more so.

The operating word here is "CLAMP" it is a true clamp that is relying on pressue and friction to hold things in place.

Any Arca plate will fit any Arca clamp regardless of length.


For balancing long lenses this is a huge advantage over a full captive QR plate system.. and the main reason why virtually every long lens user uses Arca or nothing.

I use a 7" long plate on my 500mm.. which slides into a 2.5" Arca clamp.

On a Gimble head you want perfect balance front to back.. seeing as how I can have a 1D MkII on the back of that lens.. or a 20D,. or either of the above with a 1.4X or 2X t-con.. I need a way to balance the varying weights mounted to the back of the lens..

this is where a system like arca excels. (FYI the ONLY other open channel QR system I am aware of is the Manfrotto system that is includede with there own Gimble head.)

By using the 7" long plate.. I can simply slide the plate and thus lens and camera, front to back to acheive perfect balance regardless of which camera/T-con is mounted.

One of the disadvantages is that there is no "Quick" release or install really.. (well not as quick anyway) it relies on you tightening or loosening the threaded clamp. This isn't a big problem at all.. but it is certainly not as fast as the RC2 for instance which LOCKS automatically upon plate insertion.. and is released with the flip of a lever.

[CyberDyneSystems]

One ast thing regarding Arca...

The Arca system is literally the current "End of the road" for head/QR systems... (as in all roads lead to ARCA) .. but as such it is very pricey. This is why most of us are recomending other solutions.. but if you want the best to begin with.. the most expandable. the most researched and developed,. and by far the most expensive! :shock:

..Then it is Arca all the way.

But your looking at plates that cost $50.00 each as opposed to $9.00 :rolleyes:

As Bob Gross mentioned earlier.. you can get a decent (sort of) tripod and head for $50.00...

[psychonaut]

i see.

CDS did u ever put arca type QR on a giottos head ? i think i may need a 3/8 to 1/4 bushing ... are there any problems associated with using bushings to match thread ?

[CyberDyneSystems]

My Giottos had/has an Arca on it. I think it fits without a bushing?

Either way.. I think the clamp when purchased seperately would include a bushing. Most do.

[psychonaut]

thanx.

[Mike K]

One of the disadvantages is that there is no "Quick" release or install really.. (well not as quick anyway) it relies on you tightening or loosening the threaded clamp. This isn't a big problem at all.. but it is certainly not as fast as the RC2 for instance which LOCKS automatically upon plate insertion.. and is released with the flip of a lever.

I see that this thread is over 1 year old, but since it is stuck to the forum head I thought an update would be in order. During the past year Really Right Stuff has come out with a better mousetrap, er.. better Arca style clamp. Everyone simply calls it the RRS lever clamp. I have seen other lever clamps, but not as nicely made as this one. This clamp allows as quick a release as any, and if your camera has an L bracket (called L plate by RRS) then switching between landscape and portrait mode is lighting fast, only a few seconds. This is a significant improvement over the Manfrotto system as it keeps a heavy camera/lens combination centered over the ballhead, similar to rotating a lens in its collar.
http://www.reallyrightstuff.com/clamps/index.html
With the clamp all the way open Arca Swiss style camera and lens plates go straight in and out, even with safety stops on the plate. No sliding needed. With the lever in the half way position the plate is captive in the clamp, yet is allowed to slide to adjust position of the plate, for example to fine balance that large lens, TC and camera. Here the plate stops (small proturding bolt heads on the bottom of the plate) available on Wimberley, Kirk and RRS, provide assurance that the plate will not slide out of the clamp while it is being positioned. Finally fully closing the lever provides a secure grip on the plate as well as both tactile and visual reassurance that the clamp is fully tightened. Once I had my camera L plate jam at an angle in a screw style clamp and was fooled into thinking that it was tight, as I could not turn the tightening screw any further. However, upon moving the ballhead the camera fell to the ground! The lever clamp cannot close if the plate is not properly seated, thus complete lever closure is assurance that this will type of accident will never happen.
One caveat is that there is not tension adjustment on the lever cam. There are apparently only a few plates out there (all I have hear about is original Arca plates) whose bevel is slightly different, resulting in less than full tightening of the plates by the clamp. Wimberley and RRS plates are guaranteed to fit perfectly, and I have never heard of a Kirk plate having a problem.
Both Kirk and RRS L brackets are highly regarded. Some have compared them for a given camera model, ie. 5D and found that there was no visible stability added for the left lug attachement of the Kirk over the RRS. However in that comparison, the RRS portrait orientation maintained the composition center of the landscape oreintation,while the Kirk required a recomposition movement of the ballhead. The only other small feature of the RRS is that the new brackets are starting to ship with indexing marks on both the landscape and portrait arms of the bracket, useful for centering the camera for pano rotations. Finally, the latest RRS camera brackets for non-1 series cameras without grips are coming out with a handstrap lug on the right side.
Mike K

[ben_r_]

CDS was right.... "All roads lead to Arca." I have been through Bogen RC2 then RC4 and after buying my first few Arca compatible accessories from Really Right Stuff, I see why I should have started here in the first place!

[RetroBlader]

Disclaimer: Sorry to revive an old thread, but as a newcomer who is looking into getting a better tripod, I was quite confused by the conflicting information as to whether Arca Type QR is still universal in this day and age of lever clamps. I ended up finding the answer after reading multiple threads. I feel that other newcomers may find it beneficial to have the "incompatibility issue" addressed in the Stickies. However, if the Mods feel differently, please feel free to delete this post of mine. (Although I hope someone would then create a separate stickie entry addressing this issue.)


One of the disadvantages is that there is no "Quick" release or install really.. (well not as quick anyway) it relies on you tightening or loosening the threaded clamp.

During the past year Really Right Stuff has come out with a better mousetrap, er.. better Arca style clamp. Everyone simply calls it the RRS lever clamp.

As Mike mentioned before, the introduction of the lever clamps made the Arca Type QR a true quick release system. (The traditional knob-tightening approach was not exactly slow, but as CDS pointed out, not as quick as other QR systems.)

For the purists who may sneer at lever clamps, there is clealry a demand for lever clamps. In additon to RRS, Markins has jumped on the wagon as well, now offering a choice of twist-knob clamp or lever clamp for all of their ballheads:
http://www.markinsamerica.com/MA5/category.php?req=1

However, unlike twist-knob clamps which can adjust to plates of different widths (and thus making Arca-type accessories universal), lever clamps are more "picky".

RRS has the following warning on their website:
"Due to wide variations in other brands of Arca-Swiss compatible plates, we recommend using our lever-release clamps only with Really Right Stuff or Wimberley brand quick-release plates."

This seems to suggest Arca plates are no longer universal, at least not when lever clamps are involved. In fact, RRS offers trade-in discounts to users of other Arca-type plate systems (Kirk, Foba, Markins, AcraTech, Novoflex and Arca-Swiss), again suggesting that these plates may not be fully compatible with RRS lever clamps.
http://reallyrightstuff.com/QR/03.html

Before you dismiss that simply as a marketing ploy by RRS to expand its market share, Markins also puts out similar warnings:
"It is known that different brands have different sizes of Arca-Swiss style plates. [...] We strongly recommend to use a single brand of plates with this lever release quickshoe. With mixed brands of plates, the traditional screw-knob style quickshoe will be more flexible." Elsewhere on the same webpage, they seemed to suggest that RRS/Wimberley and Kirk plates are larger in size compared to the others.
http://www.markinsamerica.com/MA5/M10.php



This seems to throw a wrench into CDS' previous claim:
Any Arca plate will fit any Arca clamp regardless of length.

While length of the plates may not matter, width of the plate may be a problem.

RRS' approach to this incompatbility problem is to ask users to exchange their existing plates. Markins cleverly decided to address this issue differently, by making their clamps user-adjustable in order to accommodate different plate widths:

"Adjustable Clamping Distance (Patented): The clamping distance is user-adjustable by turning the adjustment screw for plates larger than Markins standard such as Kirk or RRS."

However, in case people they can then mix Arca-type plates from different manufacturers without care, Markins warned:
"Though Markins' lever release quickshoe is adaptable to accommodate different brands of plates, it won't be practical to do so in the field with mixed brands of plates. We strongly recommend to use a single brand of plates with this lever release quickshoe. With mixed brands of plates, the traditional screw-knob style quickshoe will be more flexible."
http://www.markinsamerica.com/MA5/M10.php



So, in summary (correct me if I'm wrong), the Arca-type QR world is now:

1. If you are willing to use the traditional twist-knob clamps, any Arca-type QR plates should work with any Arca-type clamps, even if they are from different manufacturers. (Exceptions: FLM and Graf
http://www.afximages.com/stuff/arca-plates-xref.html <== link courtesy of Bogdan)
However, one needs to accept the not-quite-as-quick-release as a trade-off.

2. If one decides to go with lever clamps, one has 2 choices:
a) RRS lever clamps (non-adjustable): One needs to stick to RRS or Wimberley plates only, or be willing to send plates from different manufacturers to RRS to exchange for RRS plates.
b) Markins' adjustable lever clamps: This offers slightly more flexibility since one can adjust the clamp width at home, but should still stick to plates from only one manufacturer.


Did I get it about right?

:D

[hollis_f]

Did I get it about right?

Yup, although I have to add that the Kirk plates I use on my gear work OK with the RRS lever clamp.

[phreeky]

Due to being linked from the sticky I thought I'd continue with this thread.

I've just dived into arca-swiss and quickly discovered how important the width of the plates/clamps are! I bought myself a Jobu clamp (twist type) and some ebay lens plates. Got them today and have found that the clamp doesn't tighten enough to actually "grab" the plates!

So straight on the net to find that most people mention the plates are 1.5" in width, or 38.1mm. Grabbing the vernier caliper I find that the ebay plate is actually ~37.5mm, and the Jobu clamp wont go any tigher than 39.3mm! Bit of an issue as you can see. It seems both are out and in opposite ways causing some obvious problems.

Anyway not wanting to muck around with sending things back I pulled the clamp apart and filed it down a touch so that it now secures the plates properly. I'm waiting on some more so called "arca-swiss compatible" stuff and we'll see how "compatible" things really are.