Which memory card is best for your camera? Don’t go too cheap!
Memory cards are a small piece of plastic with all manner of chips and minute circuits inside that we don’t need to go into details with here. All you need to know is which one you need and how much space you need on that card to store any amount of images.
Types of Memory Cards
All things (cameras) are not made equal. When buying your camera, you probably won’t get any sort of memory card with it and if you do, it will only be big enough to hold a few photos (useless in other words). I suggest asking the store, or searching online, to find out which type of card your camera takes.
Most DSLR’s take the Compact Flash card (CF) as it is universally accepted in most cameras, computers and high street processing units. They can also take the SD (secure digital) cards which are becoming more popular, powerful and with more capacity.
As the name suggests, it is made very compact and uses Flash memory. The beauty of flash memory is that it has no moving parts meaning it is hard to damage or become corrupt if dropped or mishandled. In all the years I have used them, I think I had one go partially “bad” on me but I still managed to retrieve the photos and then repair the card completely by formatting it and making it as good as new…just make sure you retrieve all your photos first)!
The cards come in a variety of sizes (memory size that is, all cards are exactly the same size physically) with differing features. If you are a professional or intend to be one day, be prepared to pay a little higher for better quality CF (compact flash) cards. Do not buy cheap cards as they operate slower when both shooting and uploading images plus they can be a little less reliable.
The “write speed” in the memory card is the most critical feature looked for by most pros. The speed of the professional cameras “buffer” also plays a part in this.
Write speed = the speed in which the image data is transferred to the card from the camera, normally quoted in Mb/sec or megabits per second. Some quote the actual speed i.e. 133x or 200x write speed. This mostly won’t matter to the casual shooter but it is good to know the terminology.
Buffer = the internal memory of the camera which acts as a go between when shooting. For example, when shooting high speed photos of sports, the write speed of the CF card cannot always keep up with the camera. To save losing photos and keep you shooting, the camera will store images in its buffer until such a point where it can write the data to the memory card. When even that gets too much the camera will start to shoot slower until it catches up.
Compact flash cards were originally around 256 MB in size (256 megabytes) which on the older DSLR’s would store around 150-200 images. Each image produced by early 1 or 2 megapixel DSLR’s were around 1-2 megabytes each.
Note: Don’t get too involved with megapixels and megabytes at the moment, we will cover that later but for now, it really isn’t important. What is important is to keep reminding yourself that photography is generally a piece of cake (even with a DSLR)…point your camera, hit the shutter button, stop shooting when the card is full! When you put a CF card in your camera, it will display how many shots you are still able to take with the remaining memory on the card.
Compact Flash cards are mainly used for just cameras. Do not confuse the Micro drive with a CF card. They are the same shape and size and fit exactly the same but the Micro drive has moving parts inside…much like a miniature external hard drive for your PC. They are much easier to damage.
SD Cards (Secure Digital) – Now called SDHC (SDHC will not work on older devices)
Some DSLR’s (such as the Canon EOS 1D Mark II/III) take SD cards as well as CF cards. SD cards are a lot smaller than CF cards and somewhat more versatile. They can be used in a range of products such as digital cameras, handheld computers, PDAs, mobile phones, GPS receivers, and video game consoles, so you can see the benefits.
They, like the CF cards, are also “non volatile” and have no internal moving parts. I use the SDHC cards in both my stills DSLR and my High Definition Sony Handycam which is why the larger capacity cards (16gb, 32gb) are so useful.
There are many other types of memory cards on the market but the chances are you will use just one of the above so we will leave it at that for now.
Card Capacity – How many photos do they hold?
Now that digital has moved on significantly, most types of memory cards (at the time of writing) are coming out with some incredible storage capacity, 4gb, 8gb, 16gb, 32gb, 64gb.
Note: 1 gigabyte = 1,000 megabytes. Average images taken with a 10mp camera are about 12-14 megabytes (mb) in size when shooting RAW. So a 1gb card in a 10mp camera will hold around 60-80 photos.
There is now talk of cards being developed with around 2TB of storage capacity – 1 Terabyte = 1,000 gigabytes or 1,000,000 megabytes (Yes, one million!!!).
Believe it or not, there are 5 more stages to this going up to crazy numbers…
From Yahoo Answers: “Terabyte: A Terabyte is approximately one trillion bytes, or 1,000 Gigabytes or 1 million Megabytes. Now we are getting up there to a size that is so large that it is not a common term yet. To put it in some perspective, a Terabyte could hold about 3.6 million 300 Kilobyte images or maybe about 300 hours of good quality video. A Terabyte could hold 1,000 copies of the Encyclopaedia Britannica. Ten Terabytes could hold the printed collection of the Library of Congress. That’s a lot of data.”
It’s all getting a little crazy, let’s simplify things by working out how many images a typical card can hold when used with an average camera…
Let’s use a 10 megapixel camera and put different cards in it using different quality settings in the camera. Remember these are average figures and the memory card needs to hold back some memory for itself just like any hard drive so the figures may vary slightly.
RAW is the term for full resolution, uncompressed “lossless” images. RAW photos hold a lot more data than a typical JPEG and is the choice of most professionals. More on the benefits/downsides of this in later modules.
1GB = 60 Images
2GB = 110 Images
4GB = 230 Images
8GB = 450 Images
16GB = 1000+ Images
JPEG High Quality
JPEG is the term given by the “Joint Photographic Experts Group”, a committee who created the standard of compressing “lossy” images files sizes for maximum storage capacity. High quality JPEGs are now the “norm” for most photo applications, software programs and stock agencies. More on this in later modules.
1GB = 183 Images total
2GB = 368 Images
4GB = 740 Images
8GB = Over 2,000 Images
16GB = More than 5000 Images
JPEG Medium 1 Quality (also Medium 2 and maybe Medium 3 – not included here)
A slightly lower quality JPEG but still perfect for normal sized prints up to around 18″ x 12″ or more. Many argue that this size is perfectly acceptable for most standard printing although not good enough resolution for stock, commercial or larger prints. Excellent file sizes for maximum storage.
1GB = 242 Images total
2GB = 486 Images
4GB = 980 Images
8GB = Over 2,000 Images
16GB = More than 8000 Images
JPEG Small (web) Quality
Great if you are simply shooting photos for web use. Image file sizes are around 800kb (0.8mb) and are perfect for emailing, web use, homemade greetings cards or small publications. However, if in doubt, shoot a larger resolution and reduce the size later so that whatever happens, you know you have an original at high quality (just my 2c).
1GB = 560 Images total
2GB = 1,300 Images
4GB = Over 3,000 Images
8GB = Over 10,000 Images
16GB = Approximately 23,000 Images
It is worth bearing these figures in mind if you are, for example, going on holiday for two weeks. It is good to know that you have enough space for as many images that you think you will take.
Whilst we are on the subject of holidays, be assured that airport scanning machines will not corrupt your cards. I have shot many destination weddings and put the cards with wedding photos on through such machines…no problem.