Maybe I shouldn’t have mentioned it because it seems to create a lot of confusion. There are systems where the two channels are acquired exactly at the same time. If you take an image of EGFP and then the EGFP excitation turns off (and the filter turret turns), and finally you acquire an image of mCherry. Then, you can ignore what I say about simultaneously imaging both channels.
Is that clear?
Take care,
Omni