I did a 6-shot focus stack using f/8 with the Canon 180mm macro and Canon 5D Mark IV. I tripped the shutter the easy way by using the 2-second self-timer while touching the LCD screen that is set to sensitive. Naturally, the lens is mounted on a tripod with the collar and exposure is set by letting the first blinkies appear in the white portions of the mushrooms. I am shooting only RAW, so I know the first blinkies are not overexposed, just getting close, as the histogram and highlight alert are both based on the embedded JPEG in the RAW file, and not the RAW data. www.gerlachnaturephoto.com