The MPRS-40 and MPRS-80 are made for the Canon 800mm and 600mm F/11 prime lenses. These lightweight, extendable lenses makes proper balancing difficult; the MPRS-40 and MPRS-80 solve that problem by allowing the foot to slide back to the balance point when the lenses are extended for use, and forward when in the stowed position.

The MPRS-40 is best for lightweight setups like the RP or R6

The MPRS-80 is best for back heavy setups such as when using battery grips.

Since the lenses lack a collar, both plates include holes for mounting the optional L-plate to the foot, allowing quick and easy vertical orientation.

40mm of Sliding Travel    Thumb Screw for Quick Adjustment    Laser Markings for Repeatable Placement    QD Socket

Related Questions and Answers

Q: 1. Will this work with the QD strap swivel--is there a qd socket?

A: There is no QD socket on the Really Right Stuff 4.4" Multi-Purpose Rail (1/4"-20).

Q: 2. Will this work on the Nikon 500mm 5.6E PF lens?

A: According to RRS, the MPR-113 does work with the Nikon 500mm f/5.6E PF Lens.

Q: 3. Will this fit using two screws to the foot of the AF-S NIKKOR 500mm f/5.6E PF ED VR lens? I estimate the two threaded holes in the lens foot to be on 30mm centers.

A: The Really Right Stuff 2.9" Multi-Purpose Rail (1/4"-20) will fit the AF-S NIKKOR 500mm f/5.6E PF ED VR lens using both screws.

Q: 4. Does this work with the Really Right Stuff Quick Disconnect system?

A: Yes, it works perfectly with their quick release ball heads

Q: 5. Is any one using the 2.9 version of this as a lens foot plate on a Nikon AF-S NIKKOR 70-200mm f/2.8E FL ED VR Lens? If so, do you recommend it?

A: For that lens I have been using for years the RRS replacement foot which is great. I have used this style of plate for other lenses which do not have a specific Foot replacement. It works but is not as nice as if it was a foot replacement.

Q: 6. Is there a QD socket on the rail?

A: No theReally Right Stuff 4.4" Multi-Purpose Rail (1/4"-20) BH #REMPR113RAIL • MFR #MPR-113 RAIL does not have a QD socket.

Q: 7. Is this compatible with Arca-Swiss clamps?

A: Yes, the Really Right Stuff Multipurpose Cinema Rail (14.2") is compatible with Arca-Swiss clamps.

Q: 8. Is this plate compatible with the Manfrotto 504PLONG? I have a Manfrotto MVH502AH video head and would like to be sure I can use it on that head. Thank you

A: Yes and no. the RS2 (and by extension this Really Right stuff substitute) is compatible with with Manfrotto tripod heads but it is more difficult to use than normal Manfrotto plates. It mounts from front to back instead of back to front. The fact that it mounts in the opposite direction makes it awkward to get the quick release plate on and off your tripod. the safety mechanism can get caught leaving your camera stuck on the tripod and requiring force to remove it. Yes the plate will mount on your tripod but it will be more difficult to get it on and off your tripod than a normal manfrotto quick release plate.

Q: 9. Would I attach this to the foot of a 200-500 to make it arca Swiss compatible?

A: The rail is Arca Swiss compatible. If it will attach, it should work. Mine is used for Leica M2 & 3 bodies for a tripod and it works beautifully - the quality is exceptionally high.

Q: 10. Is this rail compatible with Arca-Swiss accessories (can it replace multi-purpose rails, like the MPR-270)?

A: The Really Right Stuff Multipurpose Cinema Rail is Arca Swiss compatible. Yes, It could replace MPR-270.