I bought a Class 4 SDHC 16GB card on ebay, I tried it with my HF100 and it films for about 30-40 sec then stop saying that the buffer memory is full.

Is it possible that the class 4 16GB card isn't fast enought for the HF100 ??

I also have a Class 6 Transcend 8gb SDHC card that works great...

Let me know what you guys think.

well it looks like you answered your own Q.....

what is the transfer rate difference you ask?

Class 2: 2 MB/s
Class 4: 4 MB/s
Class 6: 6 MB/s

I think it is recommended by canon that you use a class 6 card. It might have been class 4 and up though.
hmmm...the card could be fake. When memory cards were at its peak in price, about 90% of the cards are fake on ebay. Not sure about now but make sure you don't buy from a wholesaler that sales mostly memory cards and don't buy from a seller in china.

Stick with Class 6, I've never had a problem yet.:)

SDHC cards are rated based on write speed in BYTES not bits. Camcorders are rated at BIT rates.
Thus a class 4 card should, if it's not faulty, be capable of coping with approx 8x4 Mbps=32Mbps. Knock some off that for protocol overheads, and you still end up with a card that should cope with cameras writing 24Mbps...
I would say your card is faulty or out of spec.

That's what I tought....

I just found out that my card is a Fat32 type, is it possible that this caused the problem?

no it won't..btw if your camera says that it needs class six, then that's what you use..........

no it won't..btw if your camera says that it needs class six, then that's what you use..........
HF100s are supposed to be good for Class 4 or above. The max data rate is supposed to be 17Mbps average though I supposed since it's VBR it could peak higher than that, particularly if there is a lot of motion.
To see if it's a data rate problem, try using one of the lower rate settings.

I have a sandisk 8GB class 4 for my HF100, and it works fine.

Although, I just today bought the same card, but with 16GB from B&H and it doesn't work. I was able to make some video with it, but when I try to transfer it to my computer, ImageMixer shuts down when importing. Weird. I guess this cards can be defective? I've never had one that was bad. I'm sending this one back for an exchange.

I tried it twice, one file was about 2.2G, the other maybe a half gig. I wonder if it has anything to do with an 8GB card working and 16GB not.

I would be surprised...

The thing I find weird is when I received the card, it was showing as a 16gb card in the browser, now, only 8.38gb ! So I have the confirmation that the card is defectrive at least! But I still can't use it with the camera since I can film only 30-40 seconds at a time.... :mad: