It isnt. I ISO 80 still cannot get proper EDS. Gah.
Hi guys, because the eds has a refresh rate of 80hz, the camera
needs to be set at 1/80s for its shutter in order to capture the
eds fully. Any slower or faster will result in some parts of the
eds being cut off.
However, most consumer digital cameras does not offer an option
to change the shutter speed (you'll need an shutter priority mode
to fix the shutter speed). That's when u'll need some luck to
capture the eds nicely.
ISO refers to how sensitive your camera reacts to light, it may
affect the shutter speed, but setting the ISO wont mean that you'll
be able to capture the eds nicely.
Just my 2cents 
