dont panic, you basically just need v60 for most 4k stuff on that camera. i've been super satisfied with these for weddings because they're reliable and cheaper than the sony branded stuff.

• SanDisk Extreme Pro 128GB SDXC V60
• Kingston Canvas React Plus 128GB SDXC V90 the kingston is technically v90 but often priced like a v60, works well and i havent had any issues.

@Reply #1 - good point! V60 really is the sweet spot for the a7 IV unless you are doing super high-frame rate S&Q modes which are kinda overkill for most wedding b-roll anyway. Tbh, i've spent way too much time testing write speeds over the years and most people overpay for the Sony branded stuff. If you're running to a store right now and can't find the ones mentioned already, look for the Lexar Professional 1667x 128GB SDXC V60 or the ProGrade Digital SDXC UHS-II V60 Gold. I've used both for years and they handle 4K 10-bit 4:2:2 like a champ. Basically, the a7 IV peaks around 600Mbps in XAVC S-I, which sounds huge but actually translates to about 75MB/s. Since V60 cards are rated for a minimum sustained write of 60MB/s, you will be totally fine if you stick to XAVC HS or standard XAVC S. You only really need those crazy expensive V90 or CFexpress cards if you're shooting All-Intra at high frame rates. One quick tip tho: format the cards in the camera menu before you start shooting tomorrow... i've seen people get weird errors because they didn't do a fresh format. Also, maybe grab two 128GB cards instead of one huge 256GB one. If a card gets corrupted, you dont lose the whole wedding. Just swap them out halfway through. Good luck with the shoot!

I learned the hard way that bitrates dictate everything.

• V60 covers the cameras 600Mbps data ceiling
• I stopped getting buffer stalls once I prioritized sustained write speeds over marketing labels