EVF Delay and a maxed out Z 180-600mm lens

[Old Sub Sailor]

I had my Z 180-600mm lens on my Z8, tripod mounted to an Arca-Swiss D4 GP head. I was trying to shoot tankers that were about 9 miles away. It was a bright sunny day, shooting across Trinity Bay (Houston/Galveston Texas area) in the heat of the Texas Summer day.

When I used the vertical gear (knob) to slowly move the focus point (single shot focus) up or down to a ship, the point would continue to move in that direction and past the ship after I stopped turning the knob. At 600mm it looked like it moved a tremendous bit past the ship, but I am sure it was a fraction of a mm at that focal length, distance and background.

The Arca-Swiss folks believe that it is EVF delay, and sent me all sorts of explanations about what that is.

I was turning the knob very slowly by the way, and the ships were at anchor so they were not moving. I did have the High FPS Viewfinder turned ON, however, I also had image stabilization on (while on the tripod) which I have been reading is not a good thing. I felt that I may not have had the axis locks tight enough, and the setup was creeping a minute fraction, but was also concerned about getting them too tight so I did not crank them down. The Arca-Swiss head can easily handle the weight of that lens and camera, but I think that is still a bit of weight after all.

 

[BF Hammer]

I do not use your setup, but aspire to some day.

I do use a Z5 and an adapted Sigma 150-600mm lens. I use for astrophotography and wildlife, including flying birds. I don't have actual trouble with lag while tracking, it's when I shoot a continuous series that the action freezes for each exposure. I actually set to black out the EVF during this it mimic a DSLR blackout during exposure.

Motion causes the image to jump suddenly with stabilization on. I would certainly turn off if using a geared head that micro-adjusts. Another thought is could pre-release capture be messing this up?