Yo, congrats on the 5DIII! I've been shooting with mine for like forever and honestly it’s still one of my favorite bodies ever... totally get the "beast" comment haha. > I’ve already noticed the SD card slot feels a bit slow, so I'm curious if I should invest heavily in high-speed CF cards instead. For your situation, yeah, you absolutely NEED to go with CF cards. The SD slot on this model is basically a turtle... well actually, it’s capped at super slow speeds (like 20MB/s). If you put a fast SD in there, it actually slows down the whole write buffer for the camera, even if you’re using a fast CF at the same time!! Its kinda annoying but that's just how the older tech works. I’ve always stuck with the SanDisk Extreme Pro 64GB CompactFlash Memory Card 160MB/s and they’ve never let me down. Seriously, don't skimp on those cuz you dont want a card failure during an event. About the grip... I mean, I’m a bit of a cautious guy when it comes to weight and ergonomics. I actually prefer the Canon Battery Grip BG-E11 because it balances those heavy L-series lenses way better for portraits. Plus, it’s safer for the electronics than the cheap knockoffs... I’ve seen some third-party grips mess up the pins on the body. If you don't wanna deal with the bulk tho, just grab a couple extra Canon LP-E6NH Lithium-Ion Battery packs. Stick to the genuine ones, honestly. I've heard too many horror stories about off-brand batteries swelling or just dying mid-shoot. Anyway, hope that helps! It’s a solid kit. Peace.

yo, just catching up on this thread and honestly, congrats on the 5DIII! i still love mine for portraits. Since you mentioned the speed issue, i definitely have some technical insights that might help. Check out the 'Magic Lantern' forums online. Even if you dont actually install the firmware, their technical breakdown of the 5DIII's architecture is a great resource for understanding the hardware limits. regarding the card situation:
- Lexar Professional 1066x 128GB CompactFlash Card vs SD: Like the first guy said, CF is the way to go. The SD slot is technically capped at super low speeds and will basically choke your buffer during events.
- Power: I'm always kinda cautious with third-party grips, so I prefer swapping Canon LP-E6NH Lithium-Ion Battery packs. They're super reliable and wont let you down. it's a legendary beast and works well once you dial it in... gl! 👍

Honestly, I totally agree with the last post about being careful with cheap gear, especially for events where stuff just cant fail. Tbh though, if youre doing portraits, you realy need to look into a wireless flash system. I spent way too much time looking at the market trends for this and it basically boils down to two main options for the 5DIII right now: 1. Godox XPro-C TTL Wireless Flash Trigger - Pros: The Godox ecosystem is massive now. If you get this, you can control almost any of their lights, from tiny speedlights to big strobes. - Cons: Its a little bit more of an investment than the realy cheap stuff, and the menu takes a sec to learn.
2. Yongnuo YN622C-TX Wireless Flash Controller
- Pros: Super affordable and honestly pretty reliable for basic setups. I used these for years without many issues.
- Cons: Their system feels a bit fragmented compared to Godox lately, and the build quality is a bit more... plasticky? (at least thats how it feels to me). In my experience, Godox has definately taken over the market lately because their stuff all talks to each other so well. Even though Yongnuo is cheaper, the Godox UI is just way easier to deal with when youre in a hurry at an event. Just a thought since you'll probably want some off-camera lighting soon!

Building on the earlier suggestion, that CF card speed is the main thing to solve. The 5DIII uses UDMA 7, so while the SD slot is capped at roughly 25MB/s, the CF slot can actually handle much faster write speeds for bursts. If youre doing portraits or long events, you gotta look at the power and data compatibility too.

• Power: The Canon LP-E6NH Lithium-Ion Battery works fine in this body. Its backward compatible and gives you more capacity than the old packs, tho the 5DIII wont show the same detailed battery health stats as the newer mirrorless bodies do.
• Tethering: The mini-USB 2.0 port is a huge bottleneck for file transfers. If you tether for portraits, a Tether Tools TetherPro USB 2.0 to Mini-B 5-Pin is basically the industry standard for keeping a stable connection.
• Viewfinder: For nailing focus on portraits, the Canon Eg-S High-Precision Matte Focusing Screen is a huge help. It makes the focus pop much better than the stock screen when using fast glass like an f/1.2 or f/1.4. Just make sure your firmware is updated to 1.3.6 before you buy any huge cards. Some of the newer 128GB+ capacities wont even register correctly on the older firmware versions... i found that out the hard way at a shoot once.

Bump - same question here

Bump - same question here

Following this thread

In my experience, ensuring the physical longevity of the body is just as vital as the internals. I have tried many setups over the years, and for event photography, you really need to prioritize gear safety so you dont end up with a broken tool mid-shoot... it's basically about peace of mind.

• Get a real screen protector. The Vello Screen Protector Ultra for Canon 5D Mark III uses tempered glass, which is way safer than those cheap plastic films.
• Upgrade the strap system. The Peak Design Slide Camera Strap SL-BK-3 is essential for weight distribution when youre carrying that heavy 5DIII all day. Keeping the kit safe and comfortable is what lets me focus on the actual performance instead of worrying about a drop or a scratch.

For your situation, I'd suggest being really careful with what you buy cuz unfortunately i’ve had issues with cheap gear failing during shoots before... it was literally the worst. Basically, you definitely need a good CF card because that SD slot is just way too slow for events. Just get any fast CF card from SanDisk or maybe Delkin and you should be fine, just dont go for the cheapest no-name ones!! Here is what I would recommend:
- Get a few extra batteries from the original brand. I tried some random off-brands and they weren't as good as expected, they literally died so fast lol.
- Grab a comfortable padded strap from any big brand. The stock ones are kinda painful after a few hours of portraits.
- A basic cleaning kit from a reputable camera brand. I personally skipped the grip bc of the weight, and honestly, extra batteries are way cheaper. anyway, hope that helps!! gl!!

Been using this for years, no complaints