albireo_double

Your 63 mm lens is faulty. It will do this with any GFX body. The reason I say this is that I was about to buy a GFX with a 63 in Prague couple of weeks ago and the lens I was going to buy displayed the same behaviour with both the sale body and the store's demo body - and both bodies worked fine with the store's demo lens (which they couldn't sell me). In the end, I bought my camera/lens in another city a week later (tested both in store to make sure they work)...the sales guy told me there were some "pre-production" firmware lenses floating around that were causing this problem. In short, your body is probably working fine and you need a replacement lens.

Took delivery of the updated Roboshoots today. Using with X500 though, not the Metz. So far everything working great - TTL exposures spot on. Only one small thing was a bit strange - I had the camera set to ISO 200 and f16 but the flash showed ISO160 and f14; of course this had no impact on exposures. Sorry for not answering your specific question.

One potentially relevant aspect is that the regular 56 1.2 should focus more quickly, especially in low light, as it can take advantage of both the contrast and phase detect AF systems built into cameras like the XT2. Whereas the APD can only use contrast detect. However....if you shoot portraits you may wish to use the Face Detect / Eye Focus function, which, however, only works with contrast detect. I don't know where this leaves you for your particular purpose, but I suspect you may be better off with the regular version, if you shoot at night.

Yep, I think you are right re (i). Coincidentally, it is worth watching this video: https://www.youtube.com/watch?v=k3dvhBpNz7w They are using the LR tether plugin and it seems to work well. Besides that, I like their lighting setup a lot and the results they are getting with it. The sound on the video is pretty bad and the video is quite drawn out, but I found it educational.

If you watch the GFX videos published by Fuji, in several of them the photogs are shown using C1, either for tethering or reviewing the images (it is not clear which). But on close inspection, when you pause the videos, all the files are jpegs, not raws. At the same time, Fuji have their own LR plugin for the XF cameras and, I understand from Fuji's website, a similar LR plugin tethering solution will be provided for the GFX system. Similarly, for raw conversions, the Fuji site talks about LR and Silkypix. But why are they showing C1 screens in these promo videos, rather than LR? It may be (i) an oversight (unlikely and silly if true), (ii) an attempt to associate the GFX with "pro photographers, who mostly use C1" (which is possibly even not true and would be stupid if Fuji knew that C1 never intended to support the GFX), or (iii) an indication that the GFX will be supported by PhaseOne, after all. It is puzzling to me what Fuji are trying to tell us here.

I'll try it when it becomes available. If it can focus on the eyes swiftly, in a portrait shoot under strobe modeling lights, then I may buy one. But no preorder.

I use a Metz cable for Canon. All functions work, incl TTL.

I once had a dark stripe at the bottom of an image when using a Profoto AirRemote/D4 pack at the 1/250 sync speed with the XT-2. I continued shooting at 1/125 to be on the safe side (it was a darkened studio, so no problem). Towards the end, I switched the camera and the trigger off and on and it didn't occur again. My takeaway is to use 1/125 where it doesn't matter (studio @ f8-11) and keep checking my frames from time to time when I need the higher sync speed (outside and/or open aperture).

I have the Metz branded cable for Canon and it works fine.

I just got the EF X500 and it works really well - very quick to recharge, accurate TTL exposures, +-5 stops compensation, seamless switching to HSS. I considered the new Metz M400 but the lack of HSS put me off.

Yes, RRS make one. I've got it. Rather expensive - plus paid another EUR70 for customs VAT, ouch...

Two freezes in one hour this past week-end. New version batteries in body and grip. Started happening when I inserted/formatted two Sandisk 128GB, 95MB/s cards in the slots. No crashes until then (was using Sandisk 64GB in Slot 1 and 16GB in Slot 2, 95MB/s both). Will return to the lower capacity cards and see what happens.