@Reply #2 - good point! We've got storage and rain covered, so focus on power:

• Canon LP-E6NH Battery is reliable but pricey.
• Wasabi Power LP-E6NH 2-Pack is fantastic value! Get PCTC R5 Screen Protector!

What lens are you rocking? In my experience, ProGrade Digital CFexpress Type B Gold 128GB delivers 1700MB/s, but Lexar Professional 1667x SDXC 128GB is way more affordable for practicing with your dog.

Ngl that tshirt setup makes me nervous. The R5 is a tank but moisture can still ruin the electronics if you arent careful. I would suggest focusing on protection first and storage second.

• Peak Design Shell Camera Rain Cover Medium will protect your investment in the Seattle mist.
• Lowepro m-Trekker HP 120 Shoulder Bag fits inside a backpack while providing actual impact protection.
• SanDisk Extreme Pro 128GB SDXC UHS-II V60 provides reliable storage without the high cost of CFexpress. Be careful with the battery situation tho. The R5 is power hungry and third-party batteries often disable high-speed modes. I would suggest an official Canon LP-E6NH Lithium-Ion Battery rather than cheap alternatives. Make sure the battery door is fully latched when you are out in the rain to maintain the weather seal.

To add to the point above, Ethan is absolutely right about the power draw. Using the wrong batteries might actually slow down your burst rate which is the last thing you want when shooting a dog running around. I would suggest being extremely cautious with the Seattle humidity too. Even with a rain cover, moisture tends to find a way in. I've always found that keeping a few Dry & Dry 10 Gram Orange Indicating Silica Gel Packets in my bag is the best DIY defense against lens fogging. Since youre on a budget, you might want to consider a Domke Protective Wrap 19x19 instead of a full camera bag. Its basically a padded square of fabric with velcro that lets you turn any backpack into a safe spot for your R5 without the bulk. Its much more professional than a tshirt and much safer for the glass. Also, make sure to pick up a Sabrent Rocket CFX 256GB CFexpress Type B card if you can. They are surprisingly reliable for the price and much faster than standard SD cards. Just be careful when switching cards in the rain... even one drop in that slot can cause a real headache.

Like someone mentioned, that tshirt setup is basically a disaster waiting to happen. In my experience, if you want to keep using your own backpack while keeping the camera safe, you really should just grab a Tenba BYOB 10 Camera Insert. I've used these for years and they're way more reliable for organization than just wrapping gear in random clothes. It turns any bag into a padded camera bag instantly. Since you're in Seattle, the rain is gonna be your biggest enemy. Even with a cover, you're definitely gonna get mist on the lens. Dont ever wipe it with your sleeve or a dry cloth right away. Get a Giottos Rocket Air Blaster Large to blow off the water and any grit first. It is honestly the most essential tool for keeping your glass from getting micro-scratches over time. For the memory cards, I'd skip the budget options and go with a Sony TOUGH-G series SDXC UHS-II 128GB. These cards are built like a single solid piece of rugged plastic, so they wont break or bend like the cheaper ones often do. They're also waterproof, which fits your situation perfectly. Lastly, if you're worried about being clumsy, get a Peak Design Slide Camera Strap. The one that comes in the box is pretty flimsy and slides off your shoulder constantly. This one has a grip side and a smooth side so the camera stays exactly where you put it while you're at the park with your dog.

^ This. Also, you really need to be careful with third-party power options on a body this advanced. While generic batteries are cheaper, the R5 is notoriously picky about its power draw. Youll likely find that high-speed drive modes or specific video features wont even activate if the battery internal chips dont talk to the camera correctly. Stick with the manufacturer brand for anything important. Memory is another area where people mess up. That CFexpress slot is there for a reason. If you put a fast card in one slot and a slow bargain card in the other, the camera defaults to the speed of the slowest card when writing to both. It basically bottlenecks your entire experience. Regarding the rain, weather sealing is a total system. If your lens doesnt have a rubber gasket at the mount, moisture is gonna get inside anyway. Seattle mist is fine for a bit, but always wipe the mount dry before you switch lenses or youre just inviting corrosion. Safety first with gear this expensive.