As an aside, since you mentioned you’re on a gfx…why can’t manufacturers figure out a way to use IBIS with a tripod? Always seemed so odd to me that we just have to turn it off. Ideally you could leave it on and it would help stabilize any camera shake, even on the tripod in the wind.
With my Hasselblad x2d I’ve successfully used the 135 + 1.7 TC (230mm) with a light tripod in the wind, column center fully extended and IBIS on, with none of the usual weird artefacts that I would get on GFX or other 35mm systems when doing that.
In that particular situation, a shifted 180mm would have allowed me to frame better, while keeping the center column down, for addded stability. A 138mm would have definitely been too short.
I will need to go back to the same location, in a few months, as I need the angle of the light and level of the water to be in a specific combination in order to expose the red salt bed underneath.
I will use the GFX 100, because of the built-in mechanical shutter, with IBIS off, on the tripod, with my Arca m2 and the yet to be decided / most probably Rodie 180 tele
The framing I’m aiming for is a 15-20mm shift up, a bit of tilt for uniform DOF and then a 3 shot stitched composite with 15-20mm left / right (camera in portrait orientation). I think this will take me just outside the official Rodenstock IC, but within user reported limits of actual IC … I hope