I haven't shot fireworks before with the R5, so I set up two tripods for the 4th of July, the R5 Mark II with the 24-105 zoom set at 105, and the 6D Mark II with the 100-400 zoom set at 100. Both cameras were set for 4-second exposures, f/11, ISO 200. I used the intervalometer on both, set to five seconds, so all I had to do when the fireworks startered was to trigger both of the cameras.
At least that was the theory. It seems like they never started the show before 10:15 in the years I've been here, but this year they got going at 10:06. I didn't even have the R5 turned on because it is a bit of a battery hog, and when I did turn it on it seemed like it had lost the prefocus. So it took a few seconds to fiddle with the focus. Both cameras showed some shake on early images after I hit the buttons. I turn off the image stabilizers when I shoot on a tripod because back in the day (20 years ago) that was the advice Canon gave for most lenses. Both lenses I used are recent versions so I tried to look up current information. The Canon KnowledgeBase says, "depending on the kind of tripod and shooting conditions, sometimes it may be better to turn off the lmage Stabilizer function." In other words, maybe, maybe not.
Here are two images shot at about the same time by the two cameras. The first is the R5, the second is the 6D. I was able to crop a bit more with the R5 due to its higher resolution. The third image is from the 6D.
