Faced with the plethora of memory cards available in the market and technical jargon manufacturers, it is not always easy to know how to choose the perfect card. Being myself regularly confronted with the need to buy a new card, I decided to clear the jungle for you. The card format that accepts your photo package depends on each brand and camera model, so these information you will not be helpful at the time of purchase of the device, but rather when you will need to purchase an extra memory card for your needs well established, both can be done at the same time you will tell me and I will answer you, you're not wrong.
1. The memory card
When you trigger the photo, the data is first stored in the buffer memory of your device, while your memory card can record. This requires that your memory card has a fast writing speed, so that the memory plug your device is encumbered as little as possible. Indeed, if the buffer is full during this time of writing, then you can not take another picture. The phenomenon is particularly evident when one burst photography.
2. Memory card formats: SD or Compact Flash?
CF, SD, mini SD, micro SD, xD, MMC, SDHC, MS, MS, MS Duo, MS Pro, MS Pro Duo, MS Micro, RS-MMC, this is not the memory card formats that are missing! in this article I will address only the two most used on cameras currently models: Compact Flash and especially the SD (the most common).
Compact Flash (CF)
CF cards have larger dimensions than the SD (42.6 × 36,4x5mm), which is not found in the small devices. We can also consider that they are more cumbersome, even if it does not exaggerate: an object 4cm thick 5mm is relatively easy to store in a camera bag These cards are very reliable and offer faster write speeds. They are mostly used on the SLR, say semi-pro to pro.
Secure Digital (SD)
SD cards are smaller objects (24x32x2,1mm). This compactness has led to their popularity, and is now the most common format in all compact, bridges, hybrid and entry SLR / midrange. Their performances are less than CF cards However, we must increasingly moderate this assertion, as technical advances are to approach the performance of two types of cards, including SDXC.
3. The storage capacity
Regarding the jargon, you will find 3 mysterious acronyms on SD cards, designating it the storage capacity:
> SD for a capacity up to 2GB
> SDHC (HC = High Capacity, "High Capacity") for a capacity between 4 and 32GB
> SDXC (Extended capacity for XC = "extended capacity") for more than 32GB up to 128GB or more in the future! the capacity of a memory card is expressed in GB (gigabytes) or gb (Giga bytes). Capacity is exactly the same, just the second term is English. To calculate the number of storable pictures on your memory card, observe the average weight of your images. If on average each photo weighs 10MB, then you will be able to register 100 on a 1GB card, 200 on a 2GB card, 1600 on a 16GB card, etc. Before you buy a new memory card, check well in your manual types of cards compatible with your camera (in fact, a case which is not new can very well accept the SD format, but not the SDHC or SDXC).
It measures the transfer rate maximum and is expressed in megabytes per second. Example: 45MB/s means your memory card can save your images to the maximum speed of 45MB/s. Thus, if the weight of your RAW files is averaging 15Mb, your card will be able to save three per second.
Warning: please note that this index expresses the maximum speed. This rate may be lower in reality (rather weak battery, very cold or very hot environment, use burst mode, etc., etc.)
5. Speed "X"
It's the same principle as the index of maximum speed, expressed differently in multiplications ;). From a Reference writing speed 0,15Mo/s, that is said card is "x200" when will 200 times faster than the base unit, or 30MB/s.
SD cards are classified by minimum write speeds, thanks to notes from class 1 to class 10 (10 being the best). Example: a Class 10 card has a minimum write speed of 10MB per second. A Class 4 card has a minimum write speed of 4MB/s. You will therefore noted that unlike the maximum speed rating, the class reflects the minimum speed.
Easy, right Yes, but it's not all, the names have evolved to classify the most recent card formats that are faster (SDHC and SDXC): there are now ranked the UHS (Ultra High Speed = "Ultra High Speed ") from U1 to U3. the U1 class equivalent to the previous class 10 (10MB / s))
7. How many photos your memory card can save?
Here is a table approximate number of pictures you can record on a memory card. The weight of a picture depends on the file format (JPEG or RAW), JPEG compression, ISO sensitivity, but also the number of details in the image (a photo of a blue cloudless sky will be lighter than a photo of crowd or forest). The figures below are therefore given that indication to give you an order of ideas of the storage capacity of a memory card:
INDICATIVE NUMBER OF STORABLE PICTURES ON A MEMORY CARD
10MP JPEG 288 2
228 RAW JPEG 577 4
457 RAW JPEG 155 9
915 RAW 18310 JPEG
12MP JPEG 907 1
190 RAW JPEG 814 3
381 RAW JPEG 629 7
762 RAW 15258 JPEG
16MP JPEG 430 1
143 RAW JPEG 861 2
286 RAW JPEG 722 5
572 RAW 11444 JPEG
22MP JPEG 040 1
104 RAW JPEG 080 2
208 RAW JPEG 161 4
416 RAW JPEG 322 8
(Source: © Sandisk Calculated from a JPEG 100% quality = visually lossless JPEG compression with 1:10 ratio of RAW image.)
8. What brand to choose?
There are many brands of memory cards on the market. Honestly, I have only tested the two most renowned for their reliability: SanDisk and Lexar. I am in no position to give a critical review of other brands. Already lived Having the (very) bad experience of seeing a bugger memory card and thus losing all my photos, I advise you to choose the reliability, even spend 10 € Furthermore. A reliable memory card will accompany you in effect for several years.
9. Good practices: my advice
Just a few years back from a trip to Bangkok, Thailand, I plug my memory card on the card reader and Zmmm, nothing, all photos were erased in a second flash ("It's Bestel, he wanted to try something, he plugged the sensor on the Cibie and it made pffffft "little challenge, if you have recognized what movie comes this replica, say so in the comments ). Enough of tall stories, I can assure you that this is a very disappointing moment to pass. So to avoid this kind of inconvenience, here are my tips::(
Avoid too much capacity cards
Rather than buying a 64GB card, take four 16GB. Certainly you spend fifteen euros more. But let's be logical, what, compared to the expensive price forrrt your device? If you had to lose a memory card or to be bypassed when transferring images, you lose and the 16GB maximum which is always less badly than lose 64GB of photos!
Treat your memory cards
These small electronic devices are fragile: therefore avoid exposing them to dust, liquids, in short, everything that could oxidize or alter the electronic components of your card. Keep them well away in their little plastic box of origin, or in a small specialized storage bag.
Do not turn off too quickly
When you have taken a picture, allow time for your device to save the image to your memory card before you turn everything off. It's safer. On some devices, a set of lights indicates that recording is in progress (that is for example the case on my Fuji X-E1, with two LEDs located next to the viewfinder). Most devices now have a security system that prevents power from being cut as the writing process on memory card is completed, even if you think you have turned off the device. It is reassuring but does not prevent you to be careful. Finally, this seems obvious, but stay patient and be sure that the unit has had time to save your photo before removing the battery or memory card!
Empty your memory cards regularly
Once you have the opportunity, upload your photos on computer. Thus, in case of bug later, you will have already saved the maximum of images. Furthermore, it is important to work your photos from the hard drive of your computer, especially not directly from the memory card! It's best to have problems.
Is it sometimes need to format memory cards?
Yes. It is good to format your card from time to time (rather than simply delete the photos one by one) because, strength, fragmentation of recorded data can result in slower read / write speeds of your memory card. Some also think that this reduces the risk of file corruption, that is to say the risk of bugs on your photo files (yes, I too have trouble getting me to this computer term "corruption" Yet it meets the definition of the word)
The higher the resolution of your sensor, the greater the weight of your photo files will be heavy. It is therefore necessary to provide a large storage capacity, but also a faster write speed to prevent your device freezes time to record each! photo on the memory card the photo size you choose, JPG or RAW, also involves large differences in weight files: RAW files weigh heavy!
• Select directly a class 10 card (U1), with a minimum write speed of 45MB/s. You should thus be quiet for a few years, even in changing aircraft in the future.
• Consider choosing a number from 8 to 16GB cards, rather than a single 32GB card.
Take care of your equipment that your memory cards are reliable as long as possible. I hope this article has helped you brighten the subject of camera memory cards. If you have comments or questions, post them in the comments below!