Ok, I should know the answer to this, but I’ve kinda, well, forgot how to do it.
So, I photograph at a sports event on a regular basis. In the summer months its held at night under arc lights. If I’m not mistaken these lights operate at 50Hz in Australia. I’m usually working with a Sony a7Riii. In order not to be distracting I use silent shutter, and that can cause significant banding.
So, what’s the formula to work out the correct shutter speed to avoid banding? I’m usually at f2.8 with iso on auto and a max of 6400.
Hope that makes sense. Thanks.
The cause is that the readout speed of the sensor is too slow (eg 1\50s), so the lights turn off and on while the sensor is reading different parts of the image. Even if you use a very fast shutter time like 1\500s
Mechanical shutter solves this as it wipes the entire sensor in like 1\200s, so the brightness change in the scene doesn’t change significantly from top to bottom.
Get a faster read camera like Canon R3, Nikon Z8\9. Or use mechanical shutter.
The Z8 / Z9 can have the same issue also…