memory cards for cameras

A Simple Guide To Memory Cards For Cameras

I am not a gear guy. Let’s get that right straight upfront. I am a shooter. There is a difference. Gear guys know all about the technical side of cameras and everything that attaches to them. Shooters ask you to explain it in layman’s terms, and then quickly figure out how to best use those capabilities. Whatever they are.

So the explanation you are going to get here is not from a technical side, but a practical side. Ready? Here we go…

There are two main types of cards that we are using right now. CF, and SD. There is a third type, but only one camera can use it, and that is an XQD card. We won’t talk about that, because most of the memory card makers refuse to make it, and only one camera on the market uses it. So let’s forget that one for now.

Here is what they look like:

sd card
SD Card
compact flash card
CF Card

First things first. Is one better than the other? Well, that depends on how you look at it. For general purposes, no. One is not better than the other. However….

If you were to look closely at an SD card, You would see it has nine pins. On a CF card, depending on the type, you get 50 to 68 pins. 

Let’s pretend that data – images – were cars. And those pins were highways for those cars to travel on. It does not take a rocket scientist to figure out that you can get data onto a CF card quicker than an SD card because it has more roads for those little cars to travel. You can also get them off the card quicker when you plug them into the computer.

Remember that we are not going to be all technical with this.

But unless you are shooting uncompressed RAW images in 15 shot bursts, it probably does not matter. Why? Because the camera has a memory of its own. Real fast memory. And those images, before they ever hit the memory card, are first written to the internal memory. That internal memory, which is way faster than the card, acts like a buffer. Images are temporarily stored there until they can be offloaded to the card.

Most cameras have a pretty large buffer. So, if one card is slower than the other, no matter what type or how fast it may be rated, you never reach a place where the camera does not shoot. Unless, of course, you are shooting uncompressed RAW images in a big long burst. And most people do not do that. If you do, then you are shooting fast-action sports. Even then, you are typically firing in 5 or 6 shots burst unless you are undisciplined and believe in the spray and pray mentality.

As you can tell from that wording, I don’t.

Now, if you are shooting fast-action sports, it makes sense to have the fastest stuff you can for those moments that require 15 shot bursts in uncompressed RAW versus jpeg. It will happen for those people. But like I said, not much. But because it will then be prepared. That means you want to shoot a 50 or 68 pin CF card in a camera that can handle that. Plus, that card needs to be rated to be reasonably fast. We will get to speed in a minute.

Let’s first go back to SD cards and expand on those. In the SD world, you have three main types. SDSC, SDHC, SDXC.

SDSC is a standard older format card for older cameras. SC stands for Standard Capacity.

SDHC is for newer cameras. Including most point and shoot cameras. HC stands for high capacity. You need to read your owner’s manual to see what type yours requires.

SDXC is for newer upper-end models. XC stands for Extended Capacity.

It is only essential to know what your camera uses. If yours uses an SDXC – and most newer DSLR cameras do – then it is backward compatible with the SC and HC models of memory cards as well. But the reverse is not true. Chances are, your camera uses XC versions as even most point and shoot cameras are using these now. But you should check to make sure.

Next to consider is speed. In speed, there are two things to consider. What is the burst rate, and what is the Class rating? Burst rate is how many megabytes per second it can transfer. Class rating is, what is the sustained megabytes per second the card can transfer. The class rating is essential for those that record video on their camera.

Generally speaking, a class-10 rated card should be fast enough for almost everyone. Class-10 is rated at 10 MBs or 10 megabytes per second. Though the burst rate will often be higher. So just do yourself a favor and buy a class 10 card. Here is a great one for under $10.

Now let’s talk about CF cards. We already explained that they are generally faster because there are more roads for cars to travel on. They are not rated in “classes,” however. They have a “times” rating. So you will see this card, for example.

It is a 400X or 400 times card. How fast is that? Well considerably faster than a class 10 SD card. A 400X card will run you about $42 for the same size one above but can transfer data at a sustained 60MBs, or 60 megabytes per second. Now you know why there is a price difference. Also, you will often find another acronym on many of those cards. UMDA. Ultra Direct Memory Access. It is how we can get even faster speeds. Most cards that are over 266X will be UMDA cards. The camera must be compatible with taking advantage of those faster speeds. Also, to offload the card at that faster rate, the card reader for your computer must be UMDA compatible as well.

Here is a great one to look at:

There is also something called type I and Type II cards. Most everything nowadays is Type II, so that should no longer even be an issue worth talking about. But Type II cards are thicker. A type I can work in a type II slot, but not the other way around.

Now I copy and paste what I said about speed above: Unless you are shooting uncompressed RAW images in 15 shot bursts, it probably does not matter. Why? Because the camera has a memory of its own. Real fast memory. And those images, before they ever hit the memory card, are first written to the internal memory. That internal memory, which is way faster than the card, acts like a buffer. Images are temporarily stored there until they can be offloaded to the card.

Most cameras have a pretty large buffer. So if one card is slower than the other, no matter what type or how fast that card may be rated at, you never reach a place where the camera does not shoot. Unless, of course, you are shooting uncompressed RAW images in a big long burst. And most people do not do that. If you do, then you are shooting fast-action sports. Even then, you are typically firing in 5 or 6 shots burst.

The bottom line is any class 10 SD card, and any UMDA or 266X or faster CF card will work plenty fast enough for almost anything you will do unless you work for Reuters and get tasked to shoot the Olympics and need blazing fast speed over long extended bursts.

FINALLY – DOES BRAND MATTER? Some will tell you yes that they will only use brand X, or whatever. But the truth is, probably not. I have yet to find a brand that outperformed any other brand in name alone. Anybody that says they have is perhaps not being very truthful with themselves. (Probably going to pay for that remark)

For the final reference, here is a chart for you to bookmark:

  • 1000x = 150MB/s
  •  966x = 145MB/s
  •  933x = 140MB/s
  •  900x = 135MB/s
  •  866x = 130MB/s
  •  833x = 125MB/s
  •  800x = 120MB/s
  •  766x = 115MB/s
  •  733x = 110MB/s
  •  700x = 105MB/s
  •  666x = 100MB/s
  •  633x = 95MB/s
  •  600x = 90MB/s
  •  566x = 85MB/s
  •  533x = 80MB/s
  •  500x = 75MB/s
  •  466x = 70MB/s
  •  433x = 65MB/s
  •  400x = 60MB/s
  •  366x = 55MB/s
  •  333x = 50MB/s
  •  300x = 45MB/s
  •  266x = 40MB/s
  •  233x = 35MB/s
  •  200x = 30MB/s
  •  166x = 25MB/s
  •  150x = 22.5MB/s
  •  133x = 20MB/s
  •  100x = 15MB/s
  •  66x = 10MB/s (SD speed class 10)
  •  40x = 06MB/s (SD speed class 6)
  •  26x = 04MB/s (SD speed class 4)
  •  13x = 02MB/s (SD speed class 2)