My 5D IV has gone really strange on me! Without me changing any of the usual settings... Set to Av, Tv, M or P in High-Speed Continuous, it has suddenly started putting in a 2-second gap between shots. While it is in that delay it shows BUSY. If I switch to the C1, C2 or C3 settings, which all include high-speed continuous, it works as normal. And, if I set it to A+ and High-Speed continuous, it works as normal! I tried with 2 cards in and just a CF and just an SD card. That made no difference. Because it seemed to be taking extra time to write, I switched from the usual RAW to small JPEG. That made no difference. Next I tried removing the cards completely and enabled 'shoot without card'. I also removed the lens. That resulted in less of a delay between shots, but still not giving High-Speed Continuous. I compared it to Low-Speed Continuous (without card or lens) and it seemed like it was the same speed. I also tried updating the Firmware to the latest version. That made no difference. Interval Timer is disabled throughout the settings. Anyone any ideas?
Just thinking through this, you did not happen to turn on a high processing option like automatic in camera HDR that would counter the cameras buffer and render the continuous shooting useless?
Thanks for getting back to me. I have never used the in-camera HDR, but I looked it up. Press the paintbrush button... Well, this gets stranger and stranger. When it brings up the screen with 3 options, including HDR, it is locked on the first, picture style icon. No amount of touching the screen or turning the wheels will change it. ???
I suspect it might worth trying removing and replacing the battery and if that fails going for a complete reset to factory values
Thanks for getting back to me. I should have put in a post to say that I contacted Canon and they resolved the problem. It was me! I must have accidentally switched on 'Digital Lens Optimizer'. I had no idea and have never used it all these years, so I knew nothing about it or the fact that it greatly slows the continuous shooting rate. I switched it off and the problem vanished.