Never Shoot Without Dual Card Slots

Never Shoot Without Dual Card Slots

In the past few weeks, Nikon and Canon have released their new mirrorless offerings, the Z7 and R, to much fanfare. Despite the great specs and form factor, I won't buy either for one simple reason: neither one has dual card slots. I never shoot anything without dual card slots, and neither should you.

When shooting for clients, shooting for myself, or just casually taking a few pictures of my kids, I always shoot with two camera card slots. I am fanatic about not losing any files, be it for clients or just myself. If it is worth shooting, it is worth protecting those files.

In the time between starting this article and finishing it, I had two photoshoots. In the second one, a compact flash card actually corrupted and was not recoverable. I tried several different software solutions, but all of them failed to recover the images on the card. 

Image Rescue was unable to recover my corrupted memory card

Even though that card corrupted during the shoot, I didn't lose a single file because I shot everything to two memory cards. I wouldn't have even tried to recover the files if I was not in the middle of writing this article because every image was safely on my other card. 

My clients pay me to deliver, and I sure couldn't ask them to redo a wedding because the kiss didn't save to my memory card correctly. 

Constant improvement by card manufacturers have led to fewer card failures, but they still happen. I'm not exactly smart enough to explain how flash cards work or what makes them fail, but I do know someone who is smart enough to understand them. Jeff Wischkaemper is a research professor in the Department of Electrical and Computer Engineering at Texas A&M University. Dr. Wischkaemper also happens to be a talented amateur photographer, so he understands the importance of memory cards to photographers.

"We used CF cards in an industrial product for over a decade. This was not a photographic application, but the primary function of the of the cards was to store files of similar size and composition to images. The CF cards were, without question, the weakest part of the system. Virtually all cards experienced some data corruption after years of use - many of them experienced complete corruption of the entire card, to the extent that no data could be read or written," Dr. Wischkaemper said.

I am all about minimizing risk and there are several ways you can do that. You can minimize risk by buying good memory cards from authorized retailers. I have less failures in my Lexars and Sandisks bought from an authorized retailer such as B&H than I have had with other brands bought in other places. I don't even want to know how many counterfeit memory cards I have used over the years because I didn't buy exclusively from authorized retailers. 

Another way you can minimize risk is changing out memory cards before they fail. As Dr. Wischkaemper said, eventually they all cards he used suffered some corruption or data loss. Replace the cards before they corrupt. Sell them or keep them as emergency backup. You can also do what I do and have a bowl of old cards on a shelf for no particular reason other than I might one day use that 1GIG 80x card from 2005.

In addition to both those ways, you should always shoot dual card slots. I only use new cards purchased from authorized retailers and I change them out regularly. But cards can still corrupt at any given moment, so every time I take a picture, it is written to card slot A and card slot B.

I choose to use raw to card A and JPEG card slot B for a couple reasons, but the main reason is when I shot Canon, I noticed that sometimes the raw file would corrupt when I was hitting the buffer, which was often on the horrible buffer and slow write speeds of the 5D Mark III. But while the raw file would be corrupted, the JPEG file on the other card slot would be unaffected and could be edited normally.

More likely than a card corruption problem, though, is human error. I've heard countless stories of camera bags being stolen, memory cards falling out of pockets, or photographers thinking they backed up the card, then shooting over it without getting all the files.

A lot of photographers suggest using smaller cards and changing them out more frequently. Delkin recently announced three new XQD cards and the smallest size was 64GB. At the time of writing this, B&H didn't offer any XQD memory cards smaller than the Sony 32GB. XQD is the only card format in the new Nikon Z7.

I actually think shooting with smaller cards and switching them out will make you more prone to lose images, because I think the more likely event is human error than card corruption. 

Large cards are all I use — large enough where I do not need to switch out cards during a shoot. I know cards aren't going to fall out of my camera and because I use two cards, I know that me losing my cards is much more likely than both cards being corrupted and unable to recover any files. My cards are only formatted at home, placed in my camera, and only come out when it is time to ingest. Never will I format a card during a shoot.

When you have formatted cards for years, it becomes a habit you can do without thinking and so if you never format during a shoot, you will never format the wrong card out of habit. After a shoot, my used primary cards go into a Think Tank Pixel Pocket Rocket and that stays tethered to me. My secondary cards stay in the cameras. If someone steals all my gear after a shoot, I still have the primary images.

I am really excited to see what my friends, colleagues, and sworn enemies do with these new Nikon and Canon mirrorless cameras. With the great EVF and cool new features, I think we are going to see a lot of great stuff that had not been done with DSLRs. But you won't see it from me. I won't take the risk. I may fall behind the times on this new technology but the risk of losing irreplaceable images for a client is going to be substantially lower.

For years, photographers shot single images on single frames of film. If you ruined the film by not properly rewinding it or in the development process, it was gone and there was nothing you could do. Luckily, times have changed and technology has advanced.

I'll bet you Robert Capa wishes he had a second copy of all the images he shot as he landed with Company E on Omaha Beach for the first wave of attacks on D-Day. Of 106 frames Capa took on D-Day, only 8 were salvaged after the darkroom assistant turned on too much heat while drying the film.

If I lost 94% of my clients files from a wedding or portrait shoot, I doubt they would be comforted much to know that Robert Capa's film was melted almost 75 years ago so no big deal. It happens, right? It doesn't have to happen. We have the technology to do better and our clients deserve better than for us to risk their files with one card slot when there is an option for two.

Thomas Campbell's picture

Thomas Campbell is a sports and marketing photographer based in Houston, Texas. When not using his Nikons, he enjoys spending time with his family, working on cars, and cheering on the Aggies.

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Here we go.

Oh God.

I can't even start down this rabbit hole

Really, do you not even consider the physical characteristics of a card to see how reliable they will be? To place all cards in the same category and say they are all the same is ludicrous.

SD cards have exposed pins and are flimsy built. CF cards and CFast cards have tiny pins that bend. XQD cards do not have the same physical limitations of both SD and CF cards.

To shoot a wedding with a single camera is reckless, cameras also fail no matter how many slots they may have.

More is not always better.

so , nobody shot wedding with film or when the cameras only had one card ...Really ?

I take it you skipped the last sentence of the article?

Yea, you're right..... So I should take all 5 of my cameras that I use to shoot seniors and underclass pictures and buy new ones at an average price of $2000 each..... Got cha"

I take it you skipped the whole article till the last sentence?

Surely you can use the 2nd slot and everyone would do so, if your camera has one,
but you guys did not read the whole article.
It says NEVER, NEVER work without it.
I shot tons of pictures and never had a corrupted card or corrupted raw. I am wondering what he is doing? My camera on the other hand, did screwed up before. (Thats why NEVER NEVER (sarcsm ;-))) shoot without 2nd camera)
And because nowadays you can afford backups we all using them.
I save client photos on 3 different backups.
But you do NOT need to buy a new Camera just because of 2 slots. NEVER Shoot Without Dual Card Slots, doesnt make sense to me.

"People died for decades in cars without ABS, why should we start using it now? It's not like it prevented us from using cars duh"

CFast doesn't have flimsy pins like compact flash. It's more of a circuit board like connector that is much sturdier than pins. FYI

XQD cards break too. I've had two (since the first Nikon D4) that died on me.

"To place all cards in the same category and say they are all the same is ludicrous"... well yes and no. Of course not all cards are the same, but all cards have some potential for failure.

CF pins only bend if the photographer jams a CF card into a camera with some reckless force. I've never bent a pin... been using CF since the Nikon D2x.

"To shoot a wedding with a single camera is reckless..." Yep. That was true in the film days and true now. Two is one and one is none. I took 3 film bodies to weddings, and I take 3 DSLRs to weddings now (each with 2 card slots).

I mean...all points made are valid. But a good takeaway from this is to rotate or transition to new cards periodically to avoid even having the possibility of corruption. I run two SD's but the second lives for overflow, and saying as each are 128...I really don't need it but you never know if you run out of space. I don't see two slots as a necessity saying as plenty of people were perfectly fine without it before it was a thing. And I'm sure D-Day would've wreaked havoc on the camera no matter what; it's war after all.

It's not always a function of time. and what time frame or "period" is good to change cards. One of my card was bought in December and stopped working about four months later.

Why take a chance?

I had cards fail on me twice -- one was well used, second card bought the week prior the failure. Both from reputable brands and retailers. Being brand new is no guarantee of anything. I don't shoot weddings and don't obsess over it but all my cameras do have dual cards slots as the author said, if it is worth shooting, it is worth protecting the images.

Personally, I make a point to never shoot without two rolls of film loaded into my F100.


Besides, if you're shooting with an F100, I'd wager that your film is probably more reliable than the camera at this point.

Jokes aren't strawmen.

They're jokes.

Not everything on the internet needs to be an argument. Sometimes we can just have fun.



A weakness of text as a mode of communication, I suppose.

I don't think this is a straw man at all — but we should be thankful of the ability not to depend on a single point of failure if we don't have to. In the film days, the lab (even a pro lab) was less reliable than a modern card. We accepted (and were often terrified by) the risk. I once shot an important job for a big client on 35mm transparency film. The lab (a well-regarded lab in a big city) processed the film fine, but when they mounted the slides, someone screwed something up and cut all the image in half. Each mounted slide was half of the previous image and half of the next. This stuff happened. If I could have simultaneously shot two rolls at a time, I would have.

One of my early memories at my grandparents' home was all of my aunts & uncles coming for a reunion. They hired a photographer for photos of all ~30 of us together and went through some poses until the photographer had done through 36 shots and realized that he had never loaded film into the camera. The idea of corralling children again to repeat the same groups as before resulted in a set of photos where everyone just looks angry and frustrated.

I agree totally with you, Never a analog photographer shoot with two rolls.

Clickbait …


it worked...

And of course nobody took photos for money back before there were two card slots, or even cards - it was just too risky! I know I still like to load two rolls of film into my 35mm when I shoot, just in case i mess up a roll.

In the 70's we drove without seat belts on, would you do the same today? If you have the choice of being safer wouldn't you take it??

How many photographers wished they had a copy of a roll of film that came out like shit because it was defected or old?

My friend owned a lab from 1987 till 2010, he can tell you lots of stories regarding films gone bad.

With digital medium we have the choice to avoid those mishaps.

Another wannabe-snarky commenter who didn't read the last sentence of the article.

Surely you can use the 2nd slot and everyone would do so, if your camera has one,
but you guys did not read the whole article.
It says NEVER, NEVER work without it.
I shot tons of pictures and never had a corrupted card or corrupted raw. I am wondering what he is doing? My camera on the other hand, did screwed up before.
And because nowadays you can afford backups we all using them.
I save client photos on 3 different backups.
But you do not need to buy a new Camera just because of 2 slots. NEVER Shoot Without Dual Card Slots.

Times change and if it was possible to load up a 35mm camera with two rolls of film at once, you'd be damned sure tons of professional photographers back in the day would have taken advantage of it.

There's a difference between making do because you have no choice and purposely ignoring safeguards that are readily available.

Another "they shot with only one roll of film" posts. They shot with one roll of film because that's all that was available. Why a person that is shooting a paying gig would do it without the added insurance that dual cards gives is beyond me. Why take the chance when you don't have to?

Why in the film age it was not a problem, but now the photocamera that fullfill your needs have only one photo storage is a failure ?
Because other MILC cameras have dual slot ? So why even bothering about that one slot camera ? You are just doing a flawed choice and should really notice it does not fullfill all your needs !

Is it so difficult to read a datasheet and read 'one slot' ? If you cannot live with one slot cameras, just buy that 'two slot' camera and tadaaa ! No more need to whine nor cry anymore !

So what is the problem with Canon and Nikon new MILC ? Seriously ?

Do you think that during the film age that not one photo shoot was lost due to a problem with the film or developing? It was a problem, but it was the only choice at the time,

I do shoot with a two card camera because I like having that extra bit of insurance. If you don't need two slots, good for you, but don't bad mouth those of us that do not wish to take a chance of loosing a shoot because of a one card camera that had a card failure.

If you're accepting money for a shoot, you should provide the client with the best chance of receiving a professional outcome, especially for one off shoots like a wedding. A card failure may mean that you missed only 15 seconds of the wedding, but maybe that 15 seconds was the bride walking up the aisle.

I wouldn't want to have to tell the bride and groom that I missed a part of their wedding because I didn't provide equipment that would reduce the chances of a card failure compromising the outcome.

David, why go out into the street... you might die,

How many cards have you had fail on you in the last 15yrs..?

I can also say you don't need a seatbelt! I'm an excellent driver! Never got into an accident. Guess what? It's not always about you. Hardware breaks. Period.

Wait, let me get this right, you are fanatical about shooting to dual cards because you're worried one card might fail in camera.
But you format the cards on an external computer and then put them straight into the camera to shoot? Okay......

No, I format them in camera before leaving for a photoshoot. I never format anything during a shoot. Sorry I was not clear enough on that.

Pretty much EVERY camera manufacturer makes it very clear that cards should be formatted IN THE CAMERA, not the computer.

Triggered let me include all the responses (excuses)

In 723 years of shooting professionally for millions of dollars I never had a single failure.

At least they used XQD, they fail less than SD despite having zero manufacturer numbers on failure rate, TBW or life expectancy.

Just shoot with 2 cameras. Never mind the fact that this doesn’t solve redundancy at all and is an illogical solution.

I don’t need 2 card slots. I’m also really great at apologizing.

723 years is a long time.

In 20 years of digital shooting I have never lost a single image because of a card failure. My second slot is set for overflow. Hope your handlers are paying you handsomely for being their lap-dog lackey/product shill.

Good for you. Plenty of others have.

Consider yourself fortunate. I had a card fail, but it was an SD card in my 5DIII and guess what....the CF card was also gathering the data. Nothing lost.

I’ve never been in a car accident while I was driving. I still wear a seatbelt though.

In many states it;s the laws yet for dual cards :)

Other than the Think Tank Pixel Pocket Rocket, I can't see anywhere I recommended anyone buy anything.

I am a terrible shill since I am not encouraging anyone to buy anything.

I would like to encourage Canon and Nikon to put in dual card slots in their next mirrorless camera, though.

Or, have single slot and permanent memory such as a cell phone does. I would actually love that.

I do not have any handlers and if I had received any compensation, I would be required to disclose it to you under FCC laws and FStoppers' rules.

I've been asking this for a while, why aren't camera manufacturers adding physical in camera SSD drives? Doesn't have to be large, 32 to 64GB. It's plenty. I use 32GB SD cards and it serves me well. On trips I use up two at the most at full resolution RAW. It boggles my mind why this hasn't been addressed yet.

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