Two is Better Than One

Dear Bubbles:
What do I do with the two card slots in my camera?
~Karen

Dear Karen,
As an introvert who has come to find—and thoroughly enjoy—my own peace, I have frequently questioned the notion that “two is better than one” except when it comes to pie and bubbles. But I recently came upon a quote from writer C.S. Lewis that gave me pause: “Two heads are better than one, not because either is infallible, but because they are unlikely to go wrong in the same direction.”

Of course, Lewis wasn’t referring to photography when he wrote this, but his quote speaks well to the main benefit of having dual memory card slots in your camera. A single memory card may fail on you, but two cards failing at the same moment in the same way is highly unlikely.

Camera manufacturers started adding the second memory card slot in modern cameras primarily to provide peace of mind in working with your data (RAW) and image (JPEG) files. One damaged card can erase an entire day’s work play. Using the second card slot can give you more capacity, create automatic backups, or separate different file types—which gives you a little more confidence that your photographs will make it safely home.

Although your camera might call it slightly different things, you can typically configure the two slots in one of four ways: standard, auto switch, dual same, or dual independent. Check your camera’s instruction manual to see how to set this up for your camera.

Most cameras, out of the box, default to standard recording. This means the camera will record data only to the card in the first card slot. The camera ignores the second card slot regardless of whether you’ve placed a card in the second card slot.

Memory card defects aren’t common, but memory cards can degrade over their lifespan, especially with heavy use. Knock on wood, I’ve had two major card failures in the 20 years of photographing in the digital world. Neither happened because I trashed the cards. They just failed. Fortunately, I didn’t lose every photograph I’d made that day. Ever since then, I’ve treated memory cards like spare tires. You hope you never need the backup, but you’re awfully glad it’s there when you do. Trusting all your images to a single piece of plastic sure tempts Murphy’s law…

Like the standard function, the auto-switch capability also only records single images. The camera will first record to the memory card in the first card slot. When that fills, the camera automatically starts recording to the memory card in the second card slot, assuming you have a card in that slot.

Auto-switch is an excellent way to expand your storage capability. This is helpful if you don’t want to carry a bunch of memory cards in your backpack on long travels (even if they are small and light to pack). It’s equally convenient if know you are going to make a lot of images and don’t want the hassle of switching your cards in the middle of the action in the field. Cue the wildlife, wedding, and street photographers. Auto Switch may help you from running out of storage, but it does not protect you from losing your images. If the one card fails before it fills, everything recorded to that card is still gone.

Dual same is your best bet for providing redundancy and protection against card issues. With this setting, the camera records the same files to both memory cards. Voila! Instant backup! Having two identical copies means one card failure becomes a minor inconvenience instead of massive heartbreak. It provides a cheap insurance policy before you can get to downloading your files onto your computer’s or an external hard drive. This is usually what I have set in my Olympus—I double check this setting as soon as I load my cards into my camera.

The last option is dual independent, or file separation mode. This setting enables the camera to record and store different file types on different cards. RAW on one card; JPEGs on the other. RAW for more involved editing later; JPEG for sharing immediately. Lose the RAW card, and you’d still have your JPEGs. Lose the JPEG card, and you’d still have the RAWs. Not 100% redundancy but better than nothing. (It’s worth noting here that some newer cameras can also separate videos from stills onto separate cards now too.)

A few more things to consider when using dual card slots:

• Use memory cards with similar speed ratings. Your camera can only write as fast as the slowest card. If one card is significantly slower than the other, your burst shooting speed and buffer clearing times may lag. If your memory card speeds do differ, use the faster one in the primary card slot.
• Use memory cards with similar sizes/storage capacities. If you’re recording backups, pairing a small card with a big card offers little advantage. The camera stops recording once the smaller card fills. That said, if you’re recording RAW and JPEGs, you have some leeway with this so long as you put the larger size memory card in the first slot (and assign it to RAW) and let the camera record JPEGs onto the smaller, secondary card.
• Choose high-quality memory cards from reputable manufacturers for most reliable, and longest, performance (and to reduce the risk of memory card failure).
• Format both cards in the camera before recording new files. For more about this, please refer to my article, “Reformatting Memory Cards” on Dear Bubbles: https://dearbubbles.com/2023/09/reformatting-memory-cards

Now, even if you decide to use two cards in camera for redundancy, it is not a great substitute for long-term backups. As soon as you return home, download your images to your computer and at least one additional backup location before formatting your cards for your next adventure. Get into the habit of downloading both cards at the same. Otherwise, it’s super easy to forget which card is which and whether you’ve backed up the images from them. I’d recommend keeping both cards together until you’ve verified that your photographs exist safely in at least two other locations. For more about how I approach digital asset management, visit https://dearbubbles.com/2020/03/dam-sorting-out-image-management/.

So, should you use both card slots? In my opinion, absolutely. We spend thousands of dollars on cameras, lenses, computers, backpacks, and travel. Compared to all of that, a second memory card costs very little, yet it can protect photographs that are impossible to recreate. Whether you choose to use the second slot for additional storage or as an instant backup, using it is a simple way to make your camera work a little harder for you. It put to good use one of your camera’s most practical and valuable features.

As much as this introvert enjoys proving that one can often be enough, this is one situation where I can make an exception as I do for pie and bubbles. When it comes to using dual card slot, C.S. Lewis had it right. Neither memory card is infallible, but they’re not likely to fail in the same way. And if using both card slots means your once-in-a-lifetime photographs survive to be enjoyed another day, then two really is better than one.

Be well, be brave, be wild!
~Bubbles

 

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