You are welcome. It is not HSS specific, really. This is an important difference between mirrorless and DSLR - you can see the exposure (and WB and film emulation) before the shot, depending on your settings. If is too dark (the exposure will be altered by a flash or you do a long exposure), you can switch "Preview Exposure" off to be able to compose. I use it often so I mapped it to a button as I said above so I do not have to go into the menu to switch it. The paragraph in the manual is rather brief. NB there are three settings that are cycled if you map them to a button: Preview Exposure and White Balance - Preview White Balance only - Off (Preview neither Exposure nor WB).