Shortest and lightest nodal rail for Sony A7r II setup

[derAngler]

I am searching for the lightest and most compact nodal rail for a Sony A7r II combined with a Metabones Mark IV and a Canon 16-35mm F4 lens. Also I would like to use the Canon TS-E 24mm II which is around 4mm longer in length than the zoom. So far I found the SUNWAYFOTO MP 140mm Rail Nodal Slide which is pretty short but maybe too short for this setup. RRS has a rail which is 145mm. Another rail would be the Long Rail Plate LRP-1 from Kirk which is 165mm long. Does anyone have some experience with one of those setups or can recommend any product?

[NancyP]

You need to determine the no-parallax point ("nodal point", entrance pupil + tripod offset) for your lenses. Panotools list has the TS-E 24 II at 86 mm (see http://wiki.panotools.org/Entrance_Pupil_Database) Add ~39 mm to that for A7Rii plus adapter (to mimic Canon lens flange to tripod hole size), you get 120mm, 12 cm for your NPP. Nobody seems to have posted the new 16-35mm f/4 entrance pupil. FWIW, sometimes manufacturer schematics lists entrance pupil.

[Bart_van_der_Wolf]

You need to determine the no-parallax point ("nodal point", entrance pupil + tripod offset) for your lenses. Panotools list has the TS-E 24 II at 86 mm (see http://wiki.panotools.org/Entrance_Pupil_Database) Add ~39 mm to that for A7Rii plus adapter (to mimic Canon lens flange to tripod hole size), you get 120mm, 12 cm for your NPP. Nobody seems to have posted the new 16-35mm f/4 entrance pupil. FWIW, sometimes manufacturer schematics lists entrance pupil.

Correct, the TS-E 24mm II (which I do have) will require something like the MPR-CL II rail from RRS to allow slightly more length than is actually needed, and the 16mm probably could do with much less. But the only way to make really sure for the 16-35mm (which I do not have) is to calibrate it for the NPP at a given focus distance (closer than infinity).

Maybe the folks at RRS will know what's needed for the zoom lens. However, it's likely though that the required longer length for the 24mm will dictate the shortest rail dimensions, and depending on L-plate design, that may be even a bit longer for portrait orientation than for landscape orientation tiles.

Cheers,
Bart

[derAngler]

This is very useful information. Thank you guys.

[NancyP]

Inquire at Canon-centric forums for the 16-35 L f/4 NPPs. Or maybe someone at Canon.com could help you - especially if you are looking to buy the lens.

Another source for "nodal rails" is Hejnarphoto.com , an Illinois camera-centric autoCAD and milling company run by one Chris Hejnar. I like his stuff, and the price is right. Not quite as slick as the RRS, but much cheaper. Plus, if you have custom work or a good idea you want made, he might be open to doing it.