High speed sdhc memory cards

Discussion in 'Camcorders, Action Cams & Video Making Forum' started by lfc1892, Nov 26, 2010.

  1. lfc1892

    lfc1892
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    Hello folks. I have a sony nex5 which i use quite often to shoot video as well as stills. Up until now i have only used a standard generic class 2 sdhc memory card. The instructions say to use at least class 4 yet class 2 seems to work ok. Am i missing out on video quality? Is faster better purely with respect to video quality due to compression etc? What problem does a slower than recommended card cause?

    Mnay thanks
     
  2. DolbyDan

    DolbyDan
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    class 2 means a minimum of 2mb/ps. You could have speeds up to 20mb/ps.
     
  3. lfc1892

    lfc1892
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    I get the whole faster transfer speeds, but what difference will this make to video quality? Does is even affect the quality at all or does it just mean it takes longer to store on the mem card?
     
  4. rogs

    rogs
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    You need to be clear about the way that SDHC cards are specified.
    A class 2 card can handle sustained data write (recording) speeds up to 2MB/s.
    A class 4 card up to 4MB/s...and so on.

    BUT, for some reason I fail to understand, the camera people choose to specify their data rates in Mb/s not MB/s.

    So what's the difference?--- a MB is 8 times bigger than a Mb, so that a class 4 card can handle video data rates up to 32Mb/s --way above what most HD camcorders require.

    For consumer HD camcorders, you just need to use a class 4 (or higher) card.
     
  5. ruudiboy

    ruudiboy
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    I have an HXR NX5 and use class 4 this means it can handle HD data transfer better than a class 2 if you shoot in full HD and use a class 2 you could experience slight lag or corrupt data then again you might not, i have used both 2 and 4 and believe a benefit of the higher class is when you edit it is quicker to transfer the data to your mac or PC. i use the class 2 in my Panasonic SD60 on full HD and no problems so far.
     
  6. 12harry

    12harry
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    Trust manufacturers to create confusion, esp. if it results in newbies buying a more-expensive mermory.
    (Sony/Fuji particularly do this with their x2 Cost memory, but that's marketing. SD is always cheaper)

    No manufacturer actually "makes" slow devices; it's all to do with silicon-wafer "yields".

    Another poster has suggested the cards are G'teed minimum . . .. so it's possible as the manufacturing improves, even the cheaper ones will work perfectly well. The risk about "transfer corruption" is always present and "any" memory device should be regarded as "unsafe" even when stationary, IMHO.- best to record to a second back-up.....I saw some HDD products that take card-downloads, but these are thin on the ground recently. Maybe their lack of colour-screen meant you might delete good stuf by mistake!!! Arrgh! In effect you need a portable PC to be sure your stuff is safe.
    I think the grading of Memory-cards is a bit of a marketing ploy, as I suspect the slow-spec devices are often high-speed devices with the (cheaper) label. Consumers and salesmen do the rest.

    That's it....pays yr money . . .
     
    Last edited: Dec 2, 2010

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