Canon T1i Memory Card

[rwc0920]

So, I'm getting around to buying a memory card for my T1i and people are saying to buy a class 6 or higher. I'm reading that if you buy a class 4 or lower, the video feature on the camera won't read and write correctly. Why is that? What does class 6 mean?

[tinton14]

Class 6 is just the speed it write in. Class 4 would be a little slower at saving compared to a class 6, then class 6 would be slower than class 10. Higher number means higher class also means more money. I would say don't go for the cheap ones since their class 6 may not have the same speed as a more well known brand's class 6. I don't really do videos with my T1i, but from what I've tried (using a class 4 sandisk Ultra II 16gb), I haven't had any problems with it. This is from videos that are only about 1 minute long though, so it may differ once you do longer videos.

[OsmosisStudios]

Originally Posted by tinton14

I would say don't go for the cheap ones since their class 6 may not have the same speed as a more well known brand's class 6.

Class 6 is Class 6: It's not something you can just slap on the front of a memory card. If it says Class 6, it'll have the same speed.

[ShantDotMe]

according to SD Speed Class - SD Association the SD card association, the class 4 /6 should be enough for HD / FULL HD recording.

Just be sure that its not a "counterfeit" card!! here is a good read abt it cinema5D.com • View topic - Does a Class 4 card work with T2i / 7D?

[ShantDotMe]

One more thing, there are difference between the cards manifactured by different companies that do belong to the same class.

This is because of two main reasons.
1. the class rating defines the minimum speed
* Class 2: 16 Mbit/s (2 MB/s)
* Class 4: 32 Mbit/s (4 MB/s)
* Class 6: 48 Mbit/s (6 MB/s)
* Class 10: 80 Mbit/s (10 MB/s)
So if a card transferes 4.2Mbit/s, it is still in class 4, but its faster than the other class 4 card that transfers 4Mbit/s

2. "Even though the class ratings are defined by a governing body, like × speed ratings, class speed ratings are quoted by the manufacturers but unverified by any independent evaluation process." (from wikipedia). so a cheap end co can put a class 4 label on not class 4 card & sell it!!!

Here you will see some benchmarks that do proof the situatuion Benchmarks - CHDK Wiki
note that he A480 did write (raw) 5051kb/s on EMTEC SDHC Class 4, 4GB card & 7125kb/s on Kingston SDHC Class 4 (FAT32), 8GB that is 1.4x time faster & they are both in the same class!!

Note that the battery / temperature of the camera & srounding do play a very very important role in the speed of the card too!!

[OsmosisStudios]

Originally Posted by ShantDotMe

Here you will see some benchmarks that do proof the situatuion Benchmarks - CHDK Wiki
note that he A480 did write (raw) 5051kb/s on EMTEC SDHC Class 4, 4GB card & 7125kb/s on Kingston SDHC Class 4 (FAT32), 8GB that is 1.4x time faster & they are both in the same class!!

Which only proves that Kingston should have labelled their card as a class 6.