The BEST SD Card for VIDEO & What Do The Numbers Mean? (Sony a7 III & GH5)

Explaining the meaning of the numbers, classes, and speeds on SD Card Labels & figuring out which SD card is the best to get for 4K video shooting.

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Products Mentioned:
SanDisk Extreme Pro 64GB SDXC V30:

Table of Contents:
1:06 – Basic Features of an SD Card & Photo vs Video Shooting
1:19 – The Read Speed on the Face of Card
1:52 – The Classes That Actually Dictate the Speed
2:20 – Basic Speed Class: Class 10 = 10 MB/s Write Speed
2:48 – Megabytes vs Megabits
3:11 – UHS Speed Class: U1 = 10 MB/s Write Speed
3:25 – The Roman Numerals: I = UHS-I
3:43 – SDHC: What Does the HC Mean? (FAT32)
4:15 – 4GB Limit on FAT32 File System
4:50 – SDXC: The exFAT File System Won’t Break up Video Files
5:22 – SDHC Only Reaches 32GB; 64GB Cards Will Be exFAT
5:53 – U3 – UHS Speed Class 3 = 30 MB/s Write Speed
6:03 – Video Speed Class (V30, V60, V90) – Video Recording Speed
7:07 – UHS-I vs UHS-II Cards
7:55 – UHS-II Backward Compatibility & Benchmarks
8:57 – Is a V30 Card Fast Enough for Sony a7 III, GH5, G9, etc.?
9:43 – Conclusion: Which Card to Get?
10:26 – How Long Can you Record Video with a 64GB Card?
11:00 – Dealing with Dual Card Slots: Backup Recording vs Relay

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48 thoughts on “The BEST SD Card for VIDEO & What Do The Numbers Mean? (Sony a7 III & GH5)”

  1. UPDATE – DEC 18/18 – Sony has released new firmware (v2.10) for the a7 III & a7R III that "Solves the problem caused by a specific third-party memory card, which would not be recognised by Sony cameras." I know that some of you had problems with the SanDisk cards in your Sony, so hopefully this update will fix it. Please post your results if it does/doesn't. 🤞

  2. Good show, learned a lot. I have been using SDXC micro-sd with adapter. Is their a downside to this? The micro cards are really cheap here in Saigon, the full-size cards are more than double the price. The cards I buy are SDXC 10 3 64gb

  3. I ordered SanDisk Extreme 64GB V30 U3 Micro SD Card to record 4K video. It arrived with A2 (supposedly for faster app loading) even though A2 wasn't in photo or description on Amazon product page). Should I return it for a non A2 card or does A1 or A2 not matter in regards to recording? I don't plan to do any gaming or use for apps.

  4. All your videos are so informative.
    Thank you for doing what you do!
    I love seeing notifications telling me Gerald posted a new video I get excited to see what I will learn this time 🤙

  5. Thanks so much for explaining (and showing) the difference between UHS-I and UHS-II. Very helpful. I now know that UHS-II is not supported on my camera (or sd card reader), so I don't need to bother with anything other than UHS-I (for now).

  6. You are always good brother nice video though , but i don't understand why you said sdhc is fat 32 . Any card could be fat32 or ntfs or whatever but ,size is limited with sdhc.

  7. Hey Gerald. Maybe you or someone else in the comments can help me with this. I have a A73 and I typically use a sandisk extreme pro. I typically only shoot photos but I have a heavy finger especially when shooting models and sometimes I can get a lot of photos backed up and I need to wait to show the model the photos I just took which can be quite frustrating. I ended up buying a v60 Lexar sd card which should be double the minimum write speed but when just doing a simple test they seemed to write the files at pretty much the same speeds. 🤷‍♂️ would that just be due to the cameras ability to write files? Thanks for any advice.

  8. Hi Gerald, love your videos! Just wanted to add in that if you have an SDHC card, you can use a Windows PC to manually format it as exFAT, skirting the 4GB filesize limit you mentioned. Formatting it in camera will default to FAT32 (as per the spec) but it's only a default & not a hard requirement. I tested an exFAT formatted SDHC card in my a7 III and was able to record a 30 minute, 20.2GB 4K video file in one go.

    Hope this helps someone frustrated with broken up files save some money by not buying an SDXC card!

  9. SO HELPFUL! I'm picking up a Sony a6400 today after work and since I'm an oldschool shooter (last time I shot was on a DVX-100B…..So….tape lol) I really didn't know what to look for in terms of memory cards. Thanks Gerald. As always you did a great job!

  10. I really never understood my sd cards for the past decade, but I wanted to learn and upgrade mine. Plus, I have a second slot now too. Thank you!! This was super helpful.

  11. Great video, dude, great value to the point. 1 thing one might add thought – is that f.i. the Sony A7iii has a UHS-ii slot which is highly recommended to utilize for video because using a UHS-i card like the one shown in the video in the UHS-ii card slot (or any slot really) will make the video stutter occasionally due to too "slow" writing speed. Atleast I experienced this when mixing up the slots by accident after I got the camera… it started to stutter when there was a shift in exposure (leaving the house on a sunny day (from dark to bright))

  12. It would of been so much better if they implemented the feature of recording directly through an SSD , like on the BMPCC, through USB C. + reliable, nomore worry about bitrate for a loooong time, still compact (M.2 drives), lower cost to storage… I initially thought it was possible. The last thing I wondered, is is that possible with smartphones, just not to have anymore storage limitations… Unfindable infos 🙂 I may have to test when I can (still didn't buy all the gear, including the camera ^^ ).
    The Nerdy explaination serie is the one I'll rely on & rewatch so many times more than any other videos, that I'll get Unundone at a point 😀

  13. Gerald, great, clear, and concise presentation. Thank you so much.
    You're a born teacher—excellent, with the tiny caveat that I have to have a minimum of two cups of VERY strong coffee if I want to avoid listening to your vids twice to catch all the info.
    That's okay. I love coffee.

  14. Thanks Gerald for the very informative video! Would the Sandisk Extreme Pro UHS-I 64gb be sufficient in the Sony A7iii UHS-II slot 1 or would you recommend going with the UHS-II card for 4K videos?

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