Lens support for Sigma 18-35 f/1.8, Olympus 12-100 and 75-300

My basic issue has been with the size and weight of the Sigma 18-35 f/1.8 on a Metabones adapter and a Panasonic GH4.  I've tried a few options, and finally settled on some hardware from Hejnar Photo (and Amazon).

The components are the following:

Hejnar G010-50 5-inch Long 1/2" Thick Rail (with an end screw mount)

Hejnar Standard Bar with 1.150" Wheels

Hejnar LLSR-1.25 1.25 Inch Lens Support Rail

Desmond DAC-38 38mm wide short knob Arca Clamp

3/32" Rubber Pad (spacer for the Arca Clamp)

Hejnar sells clamps, but I had a bunch of these Desmonds lying around.  Neewer makes a similar version.

Here is what it looks like:

And here it is supporting each of the three lenses in question:

Panasonic GH4 with Arca Base Plate, Metabones Nikon to M4/3 adapter, Sigma 18-35 f/1.8 lens.

There is a broad static portion on this lens, so the support adapter does not have to be adjusted when switching between Metabones Adapter and Metabones Speedbooster (they are not the same thickness).

Olympus E-M1 mk II with Arca base plate, Olympus 12-100 lens.

There is a narrow static band at the end of the lens beyond the focus ring, which fits nicely on the wheels without interfereing with the focus ring.  Once the length is set for this setup, it does not have to be adjusted to use the lens support with either configuration of the Sigma 18-35 f/1.8.

Olympus E-M1 mk II with Olympus 75-300 II lens

There is a very narrow static band at the end of the Olympus 75-300 II, but the wheels fit nicely and do not interfere with rotation of the focus ring or retraction of the lens.

Now, this lens adapter will (just) work without putting a spacer between the Desmond Arca Clamp and the Hejnar 5" Rail, but the spacer gives some breathing room and raises the Lens Support Rail, and you can set the whole thing down on a table.  I took off the stop screws on the bottom of the rail, so it can be set down on a table without tipping.

Now I can achieve stable balance of these three configurations on a tripod without worrying about excess vibrations.  Trying to support these lenses from the camera base is just not very stable.

The Hejnar parts will run around $108 (more if you buy the clamp, but I really like the Desmond for less than half the price); try to get a package discount.  Tell Chris Hejnar I sent you.

Well thought out set-up John. Looks solid

This seems extremely useful and practical for those plastic bodies such as EM5III and EM10 series.