tbh most cards are a disappointment when you actually push them for a long wedding shoot. I've had issues with cards failing to keep up with the 100Mbps bitrate sony uses for 4k. stick to these so it dont crash:

• ProGrade Digital SDXC UHS-II V60 Gold 128GB
• Angelbird AV Pro SD MK2 V60 128GB sustained write speed is what actually matters, not the peak marketing numbers on the box.

I saw this and just had to jump in because I am obsessed with memory specs! For 4k on a Sony, you absolutely need to look at the V-rating on the card. Basically, your camera is trying to shove a massive firehose of data into a tiny straw and the card is just choking. You want a V60 card for maximum reliability without spending V90 prices which are totally overkill for most wedding setups anyway. Here are some amazing options that are totally gonna save your weekend:

• ProGrade Digital SDXC UHS-II V60 Gold 128GB
• I love these things! They have a sustained write speed that is super consistent, which is exactly what you need for long wedding ceremonies. Plus, they usually cost around $55 so you could even grab two and stay under budget!
• Sony SF-M Series Tough V60 128GB
• These are fantastic because they are literally built to be indestructible. No fragile ribs or write-protect switches to break off... super reliable for high-pressure gigs. Since its a Sony card in a Sony camera, the compatibility is basically perfect.
• Sabrent Rocket V60 SDXC 256GB
• If you want massive storage for the money, this one is a sleeper hit. 256GB means you wont have to swap cards mid-reception while people are dancing! Just make sure the card says UHS-II on the front. Those have two rows of pins on the back for way faster data transfer. Stick to V60 and you wont see that error message again!

Yeah, Sony cameras are super picky about card speeds when it comes to 4K. If you see that error, it basically means your current card isnt fast enough to write the data as its happening. For a wedding, you definitely want something reliable so you dont lose the footage mid-vow or anything crazy.

• SanDisk Extreme Pro 128GB SDXC V30 UHS-I
• This is the old faithful. It should handle standard 4K just fine and its way under your $100 budget.
• Lexar Professional 1667x 128GB SDXC UHS-II V60
• This one is a step up and much more reliable for higher bitrates if you are using the nicer settings.
• Kingston Canvas React Plus 64GB SDXC UHS-II V90
• If you want the fastest speed possible for under 100 bucks, get this one. Just double check the card has a V30 or V60 mark on the front. Anything less will probably fail during the ceremony... which would be a nightmare tbh. Grab two cards if you can find a deal, because 4K eats through storage way faster than you think it will.