I wonder is any one using SDHC class 4 card and their experience of using it (any noticeable deficience)? I am planning to record AVCHD 1080i often. According to the spec the highest AVCHD is 17Mbps, where class 4 SDHC card speed at 32Mbps, therefore theroetically, class 4 SDHC card is more than sufficient, beside sony online store only sell class4 sony SDHC Card and recommended it.
Of course I could always get the class 6 or higher, but why spend the $$$ if the camera does not need the speed.
Understand theory is only a theory, It's the actual usage experience that count. Would anyone using class4 SDHC for 1080i AVCHD recording and share his experience. Thanks you all!!!!
After owning this machine for about 3 months, I have my question answered. I have tried class 4, 6 and 10 SDHC cards, and they all perform nicely without any problem, all the video (1080i) playback were smooth no matter they were recorded by class 4, 6 or 10.
Also, still very happy about my purchase, just came back from a family vacation over the summer, and this one device does it all, my camcorder is now collecting dust.
First, the math. Divide 8 (bits per byte; 8,192 bits = 1,024 bytes) into the Mbps (megabits per second) to get the megabytes per second. For example, 17 Mbps = 2.125 megabytes per second. I have a cheap Class 2 memory card that works with no problems taking full HD video. It is a bit slow though accessing newly-written photos for the first time to build database (even some of my friends have asked me!). AVCHD doesn't look better than MP4 does, and is very choppy or interlaced on my computer. In fact, it really isn't 1440 by 1080 for the MP4. It is 1920 by 1080 for mp4, and while the file size is smaller than that of AVCHD, it is p (progressive), making it better than the interlaced (and 'slower') AVCHD i (interlaced) format. If you want to record broadcast TV-quality HD video, the HX5V can't hold a candle to the Panasonic Lumix DMC-FZ35, and the new FZ100 is even better. Maybe even rivals that of DSLR video. Sony is a real stinker in low light when it comes to recording video. Its battery life would never make it past half an hour anyway, and so the Panasonic won out the deal with two hours of stage footage. That card is Class 6 in the Panasonic though. Weird, the Class 2 doesn't work as well in the Panasonic for burst photography, but haven't tried on the Sony. It doesn't appear to have a problem 'keeping up' recording HD video, but it might take a few seconds longer before it reads 'done processing.' If you think about it, knowing the bit rate for HD is at most 2 megabytes per second, and Class 2 is probably a little faster than that, and so that may explain why I haven't had a problem. Back to quality limitation, the main caveat I see in the Panasonic is that it doesn't have CMOS sensor that Sony benefits from, where its strength instead is above-par low-light photography. True, anti-motion blur or handheld twilight modes do the job, because any other mode on the Sony will be extremely blurry, especially when taking the Moon. Unless you use a tripod... On final note, because the files use compressed (lossy) codecs (as opposed to bitmap or TIFF), shooting in low light will reduce the data rate because of much lower possible gamut being detected and recorded by the sensor. When shooting in optimal lighting conditions rich in color, the data rate will probably be as described in the manual. Notice if you look at the remaining time (not all cameras have this--how much time before memory card full), it will appear to be counting the seconds down slowly at night than during day, where the pixel color value for most of the scenery is of overall lower bit value, or most of which just register as neutral or black. The camera uses mathematical estimation (same goes for the photos, where three or four seconds of HD video for the size of one 10 MP photo). What I don't like is that this Sony doesn't have gray, sepia, and other color or neutral modes as do other cameras. You have to consider futuristic caveats beyond the memory card class, as I feel this is of little importance, unless you are using a professional-level camera whose data rate is much greater.