Oh man, congrats on the 5D IV! Honestly, it's such a workhorse. For 4K video, you highkey need fast cards because that MJPEG codec is a storage hog. I compared the SanDisk 128GB Extreme Pro CF Card 160MB/s which is about $90, against the Lexar Professional 1066x 128GB CompactFlash Card at around $70. The Lexar is way better value and I've had zero issues with internal recording. Regarding the grip, the official Canon BG-E20 Battery Grip is like $280... basically a ripoff imo. I went with the Vello BG-C14 Battery Grip for Canon 5D Mark IV for about $90. It feels solid and works perfectly for those long event days. Also, definitely skip the pricey OEM batteries. I'm super satisfied with the Wasabi Power Battery 2-Pack and Dual USB Charger for Canon LP-E6N—you get two batteries and a charger for like $30, whereas one Canon battery is $80! For protection, I just use the Vello Screen Protector Ultra Glass for Canon 5D Mark IV. It's cheap and saves the LCD from scratches. So yeah, save your money for glass! gl!

Totally agree with the above! The 5D IV is amazing but honestly, I'm always kinda scared of third-party batteries failing during big events lol. Ngl, I found it's cheaper to just buy used Canon LP-E6N Lithium-Ion Battery packs for like $35 on eBay! Also, grab the Expert Shield Crystal Clear Screen Protector for Canon 5D Mark IV for about $15. It’s a lifesaver for resale value!! hope that helps u save some cash!

Ok so, congrats on the 5D IV! It's still such a solid workhorse even today. Before I give my full two cents, are you planning to shoot with dual cards for backup during your events, or just one at a time? I ask because the SD slot on this body is a major bottleneck compared to the CF slot - if you mirror them, the whole camera slows down to the SD's speed, which can realy mess with your 4K buffer if you aren't careful. I've spent a lot of time looking at card performance vs cost, and honestly, don't sleep on the Delkin Devices 128GB Cinema CompactFlash Card. Compared to the usual big brands, Delkin is known for their '48-hour replacement' warranty which is a lifesaver for pros. They are super rugged and built for high-bitrate video. Alternatively, if you're looking for a budget play, the Transcend 128GB CompactFlash 800x is usually way cheaper. It can technically handle the 5D's MJPEG 4K codec, but it doesn't have the same heat resistance as the Delkin. The Delkin is definately the better long-term investment for event work where you can't afford a card error, but the Transcend is okay if you just need a spare.

Regarding what #5 said about "Nice, didn't know that" - that SD slot bottleneck is a real issue you need to watch out for. I am actually gonna disagree with the advice to buy used batteries tho. For weddings or big events, I would suggest staying away from used cells because you cant verify their health or how they were stored. Instead of risking a sudden shutdown, you might want to consider something like the SmallRig LP-E6NH USB-C Rechargeable Camera Battery. They cost about $40 and having that built-in USB-C port is a game changer if you need to top off from a power bank between sets. Honestly, I'm always cautious about power failure. Also, since youre doing video, dust spots will ruin your footage. I was nervous at first, but I would suggest learning to do your own basic maintenance. Grab a Giottos Rocket Air Blaster Large for about $15 to keep that sensor clear. Just be careful not to touch the sensor glass directly when youre blowing air in there... it can be nerve-wracking but it saves a lot of money compared to professional cleanings. TL;DR: Skip used batteries to ensure reliability and learn to do your own sensor dusting to keep your 4K footage clean.

Nice, didn't know that

I would suggest focusing on the power and protection side of things first! Honestly, the 5D IV is such a beast for image quality, but it definitely has some quirks when you’re doing long event days or 4K video work. I'm right there with you on needing fast cards, but there's a few other things i've found helpful too. Here’s what I recommend based on my experience: - tbh i have mixed feelings on the battery grip. i bought one thinking it was a must-have for weddings but it makes the camera feel like a literal brick after 8 hours. my wrist was killing me!! lol. plus it makes it harder to balance on a gimbal for video. i think it’s better to just skip it unless you have giant hands.
- instead of the grip, i just bought a bunch of extra batteries. i went with some generic ones from amazon that were way cheaper than the brand name ones—maybe like $25 for a pair? they dont last *quite* as long, but for the price they’re fantastic value. just keep like 4 in your bag and you're good.
- definitely dont skip a tempered glass screen protector!! i actually used a cheap plastic film one at first and it was trash, so i upgraded to a thick glass one later. it literally saved my screen when i bumped it against my tripod once. - for cards, definitely go fast. that 4K MJPEG codec is basically a storage eater... i think it's like 500mbps?? i basically just use the fastest ones available, usually around 160MB/s. anyway, just my two cents... i think you’ll find your own flow, but maybe try without the grip first and see if ur arms can handle it haha. gl! 👍