08-08-2013 09:51 PM
As far as I understand, UHS-I cards are useless unless you want to run at 10Mb/s. There are lots of cheap SDXC memory cards out there but they are slow. Can you recommend the fastest card at 64Gb or 128Gb that is compatible with the camera, preferably manufactured by a major brand such as Lexar, Kingston etc. Also is it possible using SDXC cards to have video longer than 29m 59s, preferably the whole capacity of the card by formatting it with exFAT?
08-08-2013 10:11 PM
Technically Speed Class 6 should be sufficient for full HD video. Any card with Speed Class 10 card, which is pretty much all of them these days, should suffice. Shooting a high speed burst of RAW stills is far more taxing on a card than video.
I use Lexar and Sandisk. No idea why, other than they're major brands, reasonably priced, redily available, and they haven't let me down yet. Until I see data suggesting otherwise I'll recommend any of their speed class 10 cards. I stopped buying the top of the line speed cards awhile ago.
08-10-2013 12:34 AM
Class 10 is basically a "seal of approval". There were lots of companies that would make claims about speed but the catch was that the speed wasn't sustained... or it only could "read" that fast, but couldn't "write" that fast, etc. To earn the "Class 10" seal they are require to pass tests proving that their card can handle a minimum of 10 Mbps SUSTAINED (not just a burst for a short period of time) regardless of whether reading or writing. There's also a Class 6 certification but there was no Class 8.
UHS-1 is a completely different spec (backward compatible with everything else) but capable of much much faster speeds. The I/O bus speed of the slot is 104 Mbps (although the card itself may not necessarily be that fast). This requires that the camera itself has the new UHS-1 bus and only the very newest cameras have it. I don't think the SX50 has it as it's not listed in the specs.
For purposes of video, the camera needs to have a card with at least a Class 6 rating. I don't believe a Class 10 card is stricly "required" but I generally only buy Class 10 cards.
This is a bigger deal with DSLR cameras using rapid-fire (continuous burst mode) where you're shooting dozens of shots at a time (e.g. suppose you're shooting sports or action/wildlife shots) and you want to make sure the camera's memory buffer doesn't fill up as you shoot many frames per second.