Class 4 and Class 6 SDHC cards with Canon HF200

[eteune]

So I was told that Class 4 cards would be sufficient by obviously less than interested teenagers (everyone under 30 looks like a teenager to me just for full disclosure) at Fry's and Best Buy.
So now I have a couple Class 4, 8 Gig SDHC cards.
They obviously work fine with my digital still camera, but they also seem to work fine with my new Canon HF200
The videos playback fine on the camera itself, am I safe to record even at the best setting on the HF200 or do I absolutely have to return them for Class 6 cards.
Obviously Class 4 says up to 15 Mb per second read, but write slower.
This would seem to not jive with the HF200's 24 Mb/s highest rate, yet, like I said, it seems to play back fine on the camera itself.
Help me make sense of this please
important trip to Thailand coming in about a week.
thanks,

Ed

[MOVIEGEEK]

I use a Class 4(Kingston) for 1280x720p @ 9Mbps and it works fine, my Class 6(Transcend) works great in my USB reader but won't work in my camera. Transcend has a new Class 10 that's even faster but it all comes down to compatibility.
http://www.transcendusa.com/Press/index.asp?LangNo=0&axn=Detail&PrsNo=1466

[eteune]

Ok, after a little R. of T.F.M., Canon indicates that they recommend Class 4 or higher and have tested cards from Panasonic, Toshiba and Scandisk
I guess I am ok with my Class 4 Scandisk then

anyone have experience to the contrary or suggestions otherwise?

thanks

[eteune]

I use a Class 4(Kingston) for 1280x720p @ 9Mbps and it works fine, my Class 6(Transcend) works great in my USB reader but won't work in my camera. Transcend has a new Class 10 that's even faster but it all comes down to compatibility.
http://www.transcendusa.com/Press/index.asp?LangNo=0&axn=Detail&PrsNo=1466

Thanks Moviegeek, woah, Class 10?? will have to buy if I make more sales this year

[MOVIEGEEK]

BTW: 24Mbps is only 3MB/s, well under the limits of Class 4.

[eteune]

BTW: 24Mbps is only 3MB/s, well under the limits of Class 4.

megabits v. megabytes right?
how silly of me, where's my math?

thanks again

[edDV]

Some of these Canon AVCHD cams spec class 4 , others class 6. Class 4 should be enough in theory but SD cards slow with use or when near full. Best to test your SD cards at 24 Mb/s periodically for frame loss.

24 Mb/s 1920x1080i has the same compression as 1440x1080i at 17 Mb/s.

1280x720p 30p at 9Mb/s is too little IMO, 12 Mb/s or higher would be better.

1280x720p 60p would be better at 24 Mb/s (the ideal hand held format).