Shutter Type Comparisons
I was doing an experiment to see if I could measure the actual speed of the shutter on my Sony A7iv. I have a very bright green LED shining onto a sheet of paper in from the camera lens. The LED can be set to oscillate at either 500Hz for measuring silent shutter or 5000hz for measuring the mechanical shutter.
All three of these photos were taken with the same aperture, ISO and shutter speed with just the shutter type being changed, electronic shutter, electronic first curtain shutter and full mechanical shutter.
The first image makes sense, the banding is clear and there is about 33 lines at 500Hz so the readout speed of the silent shutter is about 66ms.
The second image also makes sense and shows banding, it's using an electronic first curtain shutter there are 18 lines at 5000Hz so about 3.6ms for the shutter to close, you can even see that the shutter accelerates as it moves across the sensor, with the lines being closer together at the top and further apart at the bottom.
The third image doesn't make sense, I would expect to see well-defined bright and dark bands. This was taken at 1/8000 as all the other images were and the LED frequency was 5000Hz. There should be a small slit moving across the sensor between the first and second mechanical shutters but the image shows almost no banding. Does anyone know why that's happening?