20/02/2026 2:25 pm
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Hey everyone! I recently upgraded to a Canon EOS R6 Mark II, and I’ve been absolutely loving the autofocus performance for wildlife photography. However, I’ve quickly realized that my older SD cards are becoming a major bottleneck. When I’m shooting high-speed bursts to capture birds in flight, my buffer fills up almost instantly, and I’m stuck waiting for the camera to finish writing to the card while the action is still happening. It’s pretty frustrating to miss a shot because of a slow write speed!
I’m trying to figure out the best balance between price and performance. I know these RF bodies really benefit from UHS-II cards, but I’m torn between going for the top-tier V90 cards or saving some cash with V60 versions. Does the R6 II (or the R5) actually utilize the full speed of a V90 card during 40fps electronic shutter bursts, or is the internal buffer the limiting factor anyway? Also, I’ve heard mixed reviews about reliability with brands like Lexar versus the more expensive Sony Tough or ProGrade lines.
I’m looking for something reliable that won't give me 'Card Full' or write errors in the middle of a 4K 60fps video clip either. What SD cards are you currently using in your RF setup for high-speed shooting, and which ones have given you the fastest buffer clearing times?
5 Answers
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20/02/2026 2:50 pm
Unfortunately, Lexar Professional 2000x 64GB SDXC UHS-II Card was buggy. Compared to V60s, Sony TOUGH-G series 128GB SDXC UHS-II Card is way faster... it's basically the best for clearing R6 II bursts!
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20/02/2026 3:10 pm
Honestly, UHS-II speeds are basically mandatory for wildlife. Unfortunately, some brands are sooo overpriced it's annoying. For the best value, I recommend: - Kingston Canvas React Plus 128GB SDXC UHS-II V90 (cheaper than Sony!)
- ProGrade Digital SDXC UHS-II V60 Gold 256GB V60 is usually enough for 4k60 video, but V90 clears that buffer way faster... definitely worth it if you find a sale! gl!
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19/03/2026 6:41 am
Wow ok that changes things. Gonna have to rethink my approach now.
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24/03/2026 11:42 am
Stumbled upon this today and it reminded me of when I went down the rabbit hole of write latency and bus speeds. When I first got my Canon EOS R6 Mark II, I ran my own benchmarks across various brands to see which ones actually hit their advertised peaks during sustained bursts. It’s pretty eye-opening how much variance there is between brands... some have high peak speeds but they throttle way too fast once the buffer gets hit hard. I saw similar behavior on my Canon EOS R5 too. Tbh though, I dont feel like typing out my whole spreadsheet of findings here. You should just search for that one guy on YouTube who does the storage benchmarks for Canon bodies. Just look for R6 II sd card speed test and his video is like the top result. He shows the exact seconds it takes for the buffer to clear for almost every brand on the market. It’s way more reliable than just reading the marketing stickers on the box. There are also a few database sites that track this stuff if you want the raw mb/s data.
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20/02/2026 2:25 pm
yo, i feel u... bird photography is tough!! im still new to this but i went with sony tough cards cuz i was scared. iirc, v90s are better for 40fps bursts, but theyre pricey. i would suggest trying this: get one v90 for the action and use v60 for the rest. just make sure to be careful with cheaper brands... anyway, hope that helps!! peace
