From the course: DSLR Video Tips: Cameras & Lenses

Understanding card speeds

From the course: DSLR Video Tips: Cameras & Lenses

Start my 1-month free trial

Understanding card speeds

“

Richard: One of the questions people ask all the time is what type of memory cards do I need? You know, you go to a store, there are millions of choices, you log online to an online retailer, and you're looking, and there are just so many options, because these cards are used in everything from consumer point and shoots, all the way up to high, high-end video gear, so it's kind of confusing. Robbie: Yeah, well there are really two main types of memory cards that you are going to use for most DSLRs. There is some new one on the horizon, they are coming out, but the two main ones that you are going to use are Compact Flash and SD Memory Cards. Richard: Right and SD is just Secure Digital. Robbie: Yep. Richard: And even within that there's an extra flavor of SD called SDHC for High Capacity. Robbie: Right. Richard: And that's really sort of where you are going to go. Robbie: Yeah, For SD Cards definitely want to go to the SDHC one. Richard: Okay, yeah because that allows you to store more files. The previous ones had a much lower cap, and that's probably one of the reasons why Compact Flash was so popular early on is because it had Higher Capacity. But than with SDHC they sort of caught up. Robbie: Right, and it's actually not uncommon these days that you might have cameras that have both, right? Richard: Yeah. Robbie: Commonly people think of SD Cards as being more consumerish, slower speed, not as durable, and I think that's probably pretty true. But you know and Compact Flash being a little more rugged, little more durable, faster higher capacities. But some camera manufactures like I know Nikon, you're a Nikon shooter, a lot of their cameras they have both. So the user can decide whether they want to use an SD Card or Compact Flash Card or both. Richard: And these days they've pretty much caught up to each other. Robbie: Yeah. Richard: What I think we're seeing is that it costs more money initially to you know make one or the other. Now they are just putting both in there, and you know cost per gigabyte, typically SD Cards are less expensive, because they just, they sell more of them. You know because they're used in more devices than a CF Card, usually you could find higher capacity SD Cards at a lower cost. It's not to say one is better than the other, it's just you may have a choice or you may not based on your camera. Robbie: Yeah, and that's, I think the first major decision that you have to make when you're looking at--we'll get to speed in just a second. But when you get to you know looking at whether you're going to SD or Compact Flash, it's just sort of a like size or capacity, versus speed argument, right? Richard: Yeah. Robbie: My personal feeling is to always go-- maybe it's because I am just sort of centrist in my attitude here--is to go sort of the middle of the road. I no longer--I don't necessarily need the biggest, fastest, beefiest card out there, but I obviously don't want the slowest card. Richard: Right. Robbie: I find sort of going in that middle of the road kind of card, either SD or Compact Flash is going to be fine. Because then here is the one thing that we need to remember. Is that when we're shooting video on these DSLR cameras, the bandwidth requirements aren't nearly as great as they are when we are say shooting burst mode, taking Raw photos. Richard: Well, let's put that into play here for a second. I think there's a sliding scale that people need to understand. At the low end of that scale is a JPEG shooter. Robbie: Right. Richard: Very small, even in burst mode very, very small. Robbie: Yep. Richard: Sort of next in the middle of the road is a DSLR video shooter because they're shooting lots of frames, but when you're capturing video it's a like a 2.1 megapixel file. Robbie: Exactly. Richard: Times 24 or 30 frames a second, so there are a lot of them-- Robbie: But it's so not that bad with intensity. Richard: Right, so the medium middle of the road cards work great. Robbie: Yep. Richard: Then if you go up from there like you know I shoot a lot of time-lapse, and ever since Vincent Laforet yelled at me I've started shooting my time-lapse in Raw. Robbie: Right. Richard: But man! Does the card fill up quick when you're shooting Raw time-lapse? Robbie: It does, and I think your budget and what you're shooting needs a sort of a dictate what you're going at, but you know once you sort of make that decision, okay look you know a 16 gig or a 32 gig middle of the road card is fine for me, I still think people get a little confused, right? Because they are looking at these numbers that are often on these cards and they'll say, oh 90 MB per second. Or they'll say you know 266 times, well what does that really mean? Richard: Yeah, well this one says 133x, and it's Class 10, and this one over here which is an older one says it's only 15 megs a second, I'm guessing that that's not good enough for video. Robbie: Right. So here is the deal, right? Oftentimes, either in SD Cards or in Compact Flash, you're going to see speed is shown in two different ways, either in megabytes per second as, you know, 50 MB per second, 30, you know, 90 whatever. And that's going to dictate sort of the speed that--the maximum speed that that card is able to record at and the maximum speed that you're going to able to get footage off of the card, right? Richard: Right. Robbie: You're also sometimes going to see these cards rated as you just pointed out 133x, 266x you know so on and so forth. Well, what that X means is its baseline, right? Because it's like math, high school math class, right? 133 times what. Richard: Scary Memory. Robbie: Right, exactly. Well, that X is 150 kilobytes per second, right? Richard: And we haven't talked about kilobytes per second, in kilobytes for years since floppy disks which is why it's 133 times that number. Robbie: Right. Richard: And turn that into something that's more real-world today. Robbie: Right, so if you take that baseline X has been 150 KB per second, 133 times that is about 20 MB per second, so that's the throughput on that card. Richard: So this card here that's labeled 300 MB a second-- Robbie: 30 MB a second. Richard: 30 MB a second I should say is about a 200x card. Robbie: Yeah. Richard: And why it gets confusing is I've got cards here from different manufacturers, and this one says ultra, and this one says ultra, but it's a different speed, this one says extreme. Robbie: Well, there--there is two parts of it, right? You have to sort of-- the marketing part of it-- Richard: The marketing part is usually BS. Robbie: Right, and then the real world speed. So you're going to see this real world speed in two ways, right either in megabytes per second or in that 133, 266 whatever times speed, only thing you need to remember is that that X is 150 KB per second. Richard: So I think a good baseline to remember then is that 133x is sort of the safe entry-level for shooting video. That's going to give you 20 MB a second which is going to be fine for shooting DSLR video. It's going to be great for shooting Raw photos, now may be not Raw burst mode you won't get the same throughput, but if you're just looking for DSLR video cards, that's probably fine. And I think to make this a little bit easier we do have ratings and classes that sometimes cue you that this is a card designed for video. Robbie: Well, right, and that's I said there are sort of two ways that the manufacturers advertise, there is really kind of a third way. And this especially gets a little confusing when you talk about SD Cards. Oftentimes you'll see SD Cards rated in classes, right? Richard: Right. Robbie: And to make it simple, the higher the number of the class, the faster the card is. Richard: Yeah. Robbie: So a class 10 card is going to be faster than say a class 6 card. And likewise on Compact Flash Cards when you see that it's UDMA rated, that's going to mean that it meets a certain baseline for throughput, and that's going to be a faster card than a non-UDMA Card. Richard: But not all SDHC Cards are the same, 'cause there will be different classes and not all UDMA cards are the same speed either. So that's sort of a threshold that has to cross that line. Like you could see an SDHC Card and go that's fast enough for video, but it's a class 4 card, and it may not be fast enough. Robbie: Right, and you got to test and the last thing I'll say about that besides just sort of testing ones is I've found--and I am not trying to plug you know a specific brand or anything like that--but I've found that the major players generally are pretty true to what they advertise in their speed. You know if you find you know oh I get five 32 gig cards on Amazon for a super cheap, yeah, you might be a little skeptic. Richard: Well, I got a lot of different brands up here, you know, and I've had good performance with most of them. There is one in this wall that was I not happy with. I think a good clue is if you're looking online, and you're looking at the reviews that people are posting, trust those. You know photographers and video pros tend to want to look out for each other and share good news and bad news. So you know I took a gamble, I needed a 600x card for shooting time-lapse, and I wanted that extra speed because I was going to do a whole bunch of Raw time-lapse, and I was going to be on the road. Robbie: Sure. Richard: So I bought you know a cheaper card, and I bought a more expensive card, you know, and I was able to get a 32 gig card for the same price as a 16 gig card from another manufacturer. Robbie: Yep. Richard: Well, that 32 gig card failed multiple times while shooting in burst mode and time-lapse. I'd come back and the camera was blinking from card error, and it was like, oh you mean you want 600x all the time, not some of the time. Robbie: Right, right? Richard: Oh well, we never said it did that, so you got to look at reviews and performance. And I think the other thing that is difficult for people to wrap their head around is that cost versus size argument. You want to make sure that as you do that that you're not getting cards that are too expensive, and I think you know you could just take the capacity divided by the cost and get the cost per gig, and that helps you to look at that a little bit. Robbie: Absolutely. Richard: So pretty straightforward, now we're going to specifically explore the workflows of shooting video versus photos next. But just to recap when you're out there shopping for memory cards, these days not a big difference between CF and SD Cards, it's going to vary by manufacturer. Make sure you look for those class ratings, SDHC Class 10 on up for SD Cards, UDMA ratings for video cards, and then sort of a 133x as the bottom-line cap of where you're going to go for a video rated card. If you can go a little bit faster, you'll be happier with it for both video and still work. And anything else you want to add Rob. Robbie: No, I think that about covers it Rich. Richard: All right, so there you have it. Hopefully you can shop a little smarter when you're out there looking for memory cards.

Contents