The basic push of this thread will be Micro 4/3 lens mount adapters for the GH1.

Which lens mounts are available, how well do they work, the build quality of the lens adapter and so on.
Hopefully this will allow us to weed out any poorly machined adapters, and compile a list of lens mount adapters that play well with the GH1.

Lens mount adapters I have received so far...

Contax C/Y to M4/3

Canon EF to M4/3

Arri Standard to M4/3

I will be testing these lens mount adapters this weekend and will post my results.

My initial thoughts on the Lumix GH1 M4/3 lens mount system...

The stock 14-140 lens: there is a small amount of rotational play when mounted to the camera. I am disappointed that the tolerances are not higher.

The C/Y adapter I received from Hong Kong: there is a small amount of rotational play when mounted to the camera.

The Canon EF adapter I received from Hong Kong: there is a small amount of rotational play when mounted to the camera.

The Arri standard adapter I received from Hawk in Taiwan: there is no play when mounted to the camera. This adapter is very well machined.

This might not mean much, but any rotational play in the lens mount can introduce a few millimeters of slop into a follow focus system.

Here is a shot of the Canon EF to M4/3 adapter.

Contax C/Y mount to M4/3.

ARRI Standard to M4/3 mount.

David,

Is the arri mount a similar iteration of the HotRodCamera's PL mount?

(I'm a novice at the cinema lens game)

I have the Panasonic DMW MA1 4/3 to m4/3 adapter. There is a large amount of play on this, more so than the kit lens. I'm not sure if this is just my copy or they are generally bad fitting. All the lens communication functions normally with it, but has caused some visible shifts when pulling focus, though I'm used to it now. I wouldn't want to give this combo a soaking!

David,

Is the arri mount a similar iteration of the HotRodCamera's PL mount?

(I'm a novice at the cinema lens game)

The ARRI Standard mount was an earlier mount type, followed by the ARRI Bayonet mount, and then finally the ARRI Positive Lock or PL mount.

I have the Panasonic DMW MA1 4/3 to m4/3 adapter. There is a large amount of play on this, more so than the kit lens. I'm not sure if this is just my copy or they are generally bad fitting. All the lens communication functions normally with it, but has caused some visible shifts when pulling focus, though I'm used to it now. I wouldn't want to give this combo a soaking!

I wish I could find where I put my Mic, calipers & dial indicator. I would measure how much movement is actually going on with various mount scenarios. It sounds like the DMW MA1 is in the same boat.

Well overall I'm pleased with the lens adapters I have so far, but not satisfied.
As stated earlier, the Arri standard mount adapter made by Hawk in Taiwan is of high quality with great fit.
The Contax C/Y & Canon EF/EOS from Hong Kong had a little rotational play which is a PITA when focusing.
I'm sure a strip of tape might help, but in the mean time I will be looking for other examples of these adapters with a little better fit.
For what it's worth, apparently there are only a couple of reports where the lens mount on the GH1 has a proper fit. Every other report I have come across details the rotational slop in the GH1 Lens mount. This needs to be addressed by Panasonic!

I use the Voigtlander adapters.

Pentax K, Nikon F, Leica M. All fit nicely on GH1 body.

I use Pentax, Voigtlander, Olympus, Nikkor, Zeiss, and Leica lenses on these adapters.

Leica M lenses fit a bit tightly into the adapter, they fit ok, but a bit tightly, this one is new, so perhaps it will work in fine.

All Voigtlander adapters allow focusing past infinity. I guess this is standard? To ensure that all lenses can go to infinity regardless of their age or condition or state of calibration?

Anyway too much so for my comfort, as I painstakingly made adjustments to all my lenses to reach a perfect hard-stop at infinity on all the camera platforms these lenses came from.

I adjusted my adapters by unscrewing them and placing a carefully machined shim -gasket - in each of the adapters so I can get my infinity without looking.

As expensive as the Voigtlander adapters are, I would have thought that they would have been calibrated to infinity and not past.
So is there any rotational play in the Voigtlander adapters, or do they all fit snug?

Testing is going well, but of course is taking longer than expected.
Isn't having real work in this economy great!
I have done some daytime exterior video test shots and have generally been pleased.
I'll be using the GH1 for some product shots indoors next week with my Zeiss lens kit.
Report to follow.