Why you should not delete images on your memory card using your camera!
As many of you know, I have been I have spent my life in the photography business and first went fully digital in 1997 so I literally have decades of experience dealing with the ins and outs of memory cards. While I personally use Kingston memory cards, this piece is for ANY memory card user.
First, let me explain how a memory card works in simple terms for you.
Most people look at a memory card as a piece of plastic or metal, and they don’t think much about them. But inside there is a LOT of intelligence. There is flash memory, a controller and many more electronic elements. The quality of that memory and controller often determines the speed and quality of your card.
Everything on your card is controlled by something called a File Allocation Table (FAT Table). If you think of your card as a book, the FAT Table is a Table of Contents. When you do a simple format of a memory card, you are not actually erasing the card, you are just clearing the FAT Table – removing the Table of Contents, but the chapters of the book still remain on the card, but are more difficult to recover. Yep, all the images will remain on your card until you shoot more and overwrite them. This is why you can use a program like Lexar’s Image Rescue, SanDisk’s Rescue Pro or other data recovery software to recover images from a card even after it is formatted.
This was made too apparent to a friend of mine about 15 years ago – he had shot a baseball game for his newspaper, but made the mistake of formatting the card (in camera) right after the game before he had downloaded the images. He called me in a panic to see if I could recover them. “Sure, come by the paper and I can pull everything off the card that is there AS LONG AS YOU HAVEN’T USED IT SINCE YOU FORMATTED IT.” He was in the office in 10 minutes and I used my recovery software to get his images back. One by one all of his old images started to appear in the browser window of the recovery software. A city council meeting from a week ago, an environmental portrait from two weeks ago, a track meet, a few images of the baseball game scattered through out. More started coming in, some older images. I could see the concern on his face “This will get everything off the card”, “Yes, it will get any image as long as it hasn’t been overwritten.” More older images mixed with his baseball game. More concern. Then the boudoir images of his girlfriend in lingerie started popping up from more than a month ago and I understood his concern – haha.
So here are some tips, which I am going to write in the order of importance:
1. DO NOT erase images from your memory card in your camera!
What I mean by this is: Do not go through your photos and delete them one by one using your camera. I see people (especially wire service photogs) doing this all the time and it is a REALLY bad idea. Your camera is not very smart at managing the data on your memory card. Deleting individual images from the card using your camera is a great way to scramble that FAT Table we talked about before. DON’T DO IT! Memory cards have gotten so inexpensive and large, that you should not have to delete images to save space (I know the wire service guys are editing in camera to save time, but just TAG the images, don’t delete!) Just pop in a new card and keep shooting. Once you have downloaded to your computer, and backed up the images THEN format your card to use it again.
2. Format your memory cards in your camera, not on your computer.
I have seen countless web sites which tell people to format their memory cards on your computer. This is just WRONG! You want to format the cards in the camera. And you should do this on the camera your are shooting with. I am currently shooting with the Canon 5D MkIV, Canon 1DX, Canon 5D MkIII, and I format the card in the camera I am using. You are reading this correctly…I do not format in one Canon camera and move it to another. Will they work? Yup but it may cause issues down the road. It is also terrible to pull a memory card out of one camera model and put it into another without formatting. I have seen people shooting with a Canon camera, pull the card out and start using it in a Nikon camera – Big. Bad. No. No. Each camera manufacturer has its own special sauce and likes to be formatted a certain way.
3. Format after EACH shoot.
It is a good idea to format your cards after each shoot. Once you have downloaded your card and have the images IN MORE THAN ONE PLACE, you should format that card in the camera you will be using it in before it’s next use. It keeps things cleaner on the card.
4. Use a good card reader!
I can not tell you how many times I have seen pro photographers take a high quality card out of a $10k camera and put it into a cheap no-name reader. It only causes problems. When a co-worker would ask me about a corrupted memory card, one of my first questions would be is “What card reader are you using?” Memory card readers have intelligent controllers inside them, just like the cards, and cards like the readers that have similar controllers. I have seen more cards corrupted in a reader than in a camera. I have also seen many cards that are absolutely fine in one reader, and show corruption in another reader. I use Kingston cards – I use Kingston readers.
5. Don’t fill a card completely.
Even though most memory cards are built really well and have all kinds of intelligence in them, it is not a good idea to fill a card completely. I always pull my cards (if possible) when there are a dozen or so frames left on the card. I always have dozens of cards at the ready and don’t worry about overfilling one single card. (I also do the same with my computer hard drives. I never fill them completely – there performance goes down significantly if you fill more than 90-95% of the drive).
6. Don’t pull a memory card out of your camera or card reader when data is being written or read from the card.
It’s just common sense and all of the instruction manuals will tell you in all capital letters – if data is being transferred to / from the card and that process is interrupted, it is quite possible that you will lose some or all of your photos. And don’t always trust the red light on your camera to determine is data is being transferred. Before I pull my memory cards, I always wait an extra couple of seconds after the red light on the cameras goes off, signifying that the data is done being written to the card.
7. Use both your card slots for safety.
If you have two card slots in your camera, write your images redundantly to both cards to have more safety and peace of mind. This way, if one card gets corrupted, you can most likely get the images off of the other card. In my 5D MkIV, I use both slots – the CF card is always a 16Gb or smaller card and is swapped out frequently (more on this later). The SD slot has a 256 Gb card in it that I can shoot all day on. I only depend on the CF cards for primary image transfers, but should one become corrupt, I have everything on the SD card. All cards are reformatted once all of the images have been triple backed up on my computer system.
8. Purchase name brand memory cards.
As you may have guessed, I use Kingston memory cards in all my cameras, but that is not to say that they are the only good company out there. Lexar, SanDisk and others make good products as well. There are others too, but make sure that you do not use one of those cards made by a no-named company. A simple price comparison is the key – if its cheaper than the three mentioned here – its too cheap and will be risky to use. Remember, you are trusting your images to the card! And if your a pro, your clients are trusting you with their business. You are going to be using the card over and over, so spending a couple of dollars more to get a better product, in the long run, will not cost you much more. Nothing angers me more than seeing a “pro” shooting with a great camera, expensive lens and a crappy memory card.
9. Shoot on small cards.
How many pictures can you afford to loose at once? Todays name brand camera cards are VERY dependable if treated right, but errors and failures DO and WILL happen. By shooting on small cards (16Gb) you can mitigate your loss. If everything from a wedding is shot on a 128 Gb card and it goes south – you’ve lost EVERYTHING, including your reputation (“NEVER hire him – he lost all our wedding photos”). If the same wedding is shot on eight 16 Gb cards, you’ve only lost the getting ready images or part of the reception, and you can probably sweet talk or discount your way out of a bad situation. And its not just card failures – I can’t count the number of times that I have found (unlabeled) cards on the sidelines of a sporting event or had a venue call me after an event asking if I had lost a card because it was not labeled. People (YOU and me!) are sometimes stupid and drop things – which leads me to #10.
10. Label your cards.
I have my name and phone number on ALL of my cards. A Brother PTouch Labeler can print tiny 6 pt text that will fit on the spine of your CF cards. If your card gets lost without your contact info on it, you have NO HOPE of getting it back. If its labeled, you atleast have some hope of a good samaritan calling you. 🙂
I also number all of my cards (or more precisely alphabetize them) with small peel and stick labels. This way I know at a glance that I have all my cards: A-Z. It also helps in case I have a camera error while shooting – I can pull that card – make note that card ‘H’ may be going bad, and retire it from use. Without such labelling all the cards look the same.
11. Cards wear out – replace them frequently.
In practice, it takes an awful lot of use and and abuse and isn’t a practical concern for the vast majority of weekend photographers. A figure of 100,000 read/write cycles used to be bandied as Mean Time Before Failure (MTBF), but more modern cards measure their failure rates in millions of hours of continuous use. Higher end card manufacturers build into the card controller features that help with distributing the write cycles evenly across the card so that no one spot gets much more use than any other, a process known as wear leveling. But the very fact that wear leveling is built in is a good indicator that there is some wear and tear. I replace my cards every two years. Since it was a gradual build up of cards, I am typically replacing two or three cards every month – it helps distribute the cost over time as well.
One issue that I have run into with this is the push for larger and larger cards as they get faster and faster. Its getting hard to find a speedy small card 🙁 (to comply with rule #9)
Here are some common misconceptions about memory cards:
* If memory cards get dropped in water, the data will be lost forever!
This is not true. Because memory cards are made with solid state memory, it is not uncommon for them to go through the washer and dryer and still be useable. Knowing that a card has taken such abuse I would never keep using that card. But most likely your data will still be on the card and can be recovered.
* You must keep your cards in covers.
I use the ThinkTank Pixel PocketRockets to protect my cards and forgo the little snap cases that come with the cards. The one thing you have to make sure is that lint or dirt doesn’t get into the holes of a CF card. The pins will probably push the dirt to the back of the hole, and there is a bit of room back there, but repeated build-up could cause you to bend a pin in your card reader, or worse, your camera, and lead to an expensive repair.
* Going through airport X-Ray machines can damage your cards
Many people have asked me how they should travel with their memory cards, especially at airports. In the old days, the X-Ray machines could damage high speed speed film, but X-ray machines pose no threat to the solid state memory cards you own today.
To sum all this up…
After reading this blog post, I hope you have a better understanding of your memory cards and readers and appreciate them a little more. There is so much technology packed into these devices, but they are so small and unassuming that it is easy to take them for granted.
These are simple tips that could save you from a disastrous situation. I hope that these help all of you to keep your memory cards and images safe now and in the future.
In case you are wondering…here are the cards and readers I am currently using: