Need information on unusual Sinar rail clamp

[Davros]

Can anyone give me information about this unusual Sinar rail clamp? Particularly, what the lever that does not tighten the clamp on the rail is for and why it has raised, grooved edges on the baseplate. Any help much appreciated. Thanks in advance.

Peter

[Tracy Storer]

I would be guessing, but I suspect this is not for mounting the rail to a tripod, but may be only a part of another assembly, perhaps some other part slides across this clamp and is secured with the central screw?
You could contact a Sinar dealer with the part number and ask, a Google search was not fruitful.

[fishbulb]

The clamp you have pictured has levers to clamp down on both sides instead of a long handle on one side. Both levers do the same thing, and move together - they clamp. The disadvantage of this clamp is that there is no Yaw - the camera cannot rotate to the right or left (clockwise/counterclockwise from the operator's position).

I am not sure as to why the base plate is like it is. I have wondered if Sinar sold a tripod head at some point that worked with this clamp. It doesn't look like it was designed for the Sinar Pan/Tilt head. It is very likely as Tracy said, it is used to mount an accessory to the rail. It could be designed to connect to some type of Sinar base-plate, perhaps something like this one: http://www.ebay.co.uk/itm/SINAR-Double-Clamp-Base-Plate-/171695109786

The other type of square-shaped rail clamp is very rare, but is often confused for the one you posted. It weighs about 4lbs, and has a geared movement for adjusting Yaw, which is the big knob on the right. It is designed to be used with the Sinar Pan/Tilt head. See the picture below.

136592

Besides those two clamps, there are of course the Sinar Norma style (https://farm9.staticflickr.com/8044/8081018202_5cfaee7a3a_z.jpg) (available in green and black), the Sinar F/P style (http://www.mrcad.co.uk/uploads/images/MrCad514256shop1.jpg) (and the updated all-black F2/P2 version), and the late P2 style that completely covers the rail (http://www.fredmiranda.com/forum/ufiles/94/859794.jpg). Then there is also the offset rail clamp with two knobs (http://www.leicashop.com/media/catalog/product/cache/2/image/9df78eab33525d08d6e5fb8d27136e95/1/8/18080_3_e.jpg) that is part of the table-mounting setup (available in green or black).

[Davros]

Thanks for the advice. I will take up Tracy's suggestion and contact some dealers.

For the record, it is not the case that both levers serve to operate the rail clamp. They are on different axes and only one of them performs the clamping action. The other just rotates freely and seems to do nothing at all.

Peter

[B.S.Kumar]

I have the clamp that Adam showed, and it is absolutely great for precisely leveling the camera in the studio. It's not something to toss in a backpack :)

Kumar