JeffT Loc: Central NY

I have one of these adapters that I use in Canon cameras. It is OK for single shot shooting, but is likely to fail writing when shooting events, sports, etc. in burst mode since the adapter is not likely to be fast enough during heavy writing to the card. I find this to be the case in my 7D2 which has a 10 shoots per second. It works OK with a few shoots at a time, but if you go at maximum for a over a second, I get writing errors.

I agree with the comments about the individual's requirements driving one's expectations around having 1 or 2 slots. When I shoot things where my reputation on the line, I want two slots and duplicate images. I know that I am fallible and capable of screwing up at times, especially in the "heat of the moment". I worry more about myself than the camera at times; I have never had a card fail to date, but I have had errors at times. I can understand the a pro's concerns about wanting mirrorless cameras to have multiple slots.

wrangler5 Loc: Missouri

This article by Thom Hogan https://www.sansmirror.com/newsviews/the-card-failure-issue.html was linked in another thread the other day. I had single card digital cameras until the Nikon D7000, which had 2 slots. After having 2 slots I thought it was a good idea, although since switching to Micro 4/3, most of my cameras are back to single slots. I did buy an Olympus OMD-EM1 MkII, even though I was satisfied with the earlier version, in part to get a second card slot (that, and Olympus had a smokin' deal on refurbs during a 24 hour flash sale.)

But after reading the Thom Hogan article I'm less concerned about dual slots. (The article focuses on "points of failure" in our photographic systems, which includes camera bodies, and evaluates card slots from that perspective - something I never would have thought of doing, largely because I don't have his depth of experience.) The fact that, as a working pro, he only uses one slot even if two are available, for the reasons laid out in the article, even has me thinking of doing the same thing. AND makes me much more interested in the XQD cards, which I had never heard of before the Nikon Z announcements.

Something more to think about.

camerapapi Loc: Miami, Fl.

In total agreement.

dsmeltz Loc: Philadelphia

It only becomes and issue when a manufacturer over-hypes a product announcement as the best thing since sliced bread but fails to deliver on items which are becoming the defacto benchmark. Like full frame cameras intended to change the world should deliver on a few things at this point, like awesome AF (maybe eye detect), 4K video, two slots, >10 FPS, >30MP, etc...

When a company basically says "Hey photographers, this will change your life and how you work for the better in MASSIVE ways", they had better meet base expectations or face a reaction.

It is looking like Nikon and Canon are both falling short in the mirrorless market.

NCMtnMan Loc: N. Fork New River, Ashe Co., NC

No fear about only having one slot. One of my cameras has one, the other has two. I like the two since it gives me more options. I dedicate one to RAW and the other to jpg. I have found it to my advantage at times, but not critical to my choice of camera. It is a feature to consider when purchasing, just like any other feature.

rmalarz Loc: Tempe, Arizona

None of my film cameras used two rolls of film, just one at a time. I've one digital that uses one card and another that uses two. It's never occurred to me that one was superior to the other simply based on the number of memory cards contained within.
--Bob

burkphoto Loc: High Point, NC

It’s an indication of the target audience for the camera. Two slots? It’s likely a top of line camera for pros, advanced enthusiasts, and videographers.

On most cameras with two slots, you can:

Record to one, and automatically switch to the other when the first is full.

Record raw on one, JPEG on the other.

Record stills on one, video on the other.

Record the same thing to both at the same time.

BlueMorel Loc: Southwest Michigan

It's reverse snobbery to sneer at two slots. If you want a camera that has them, then get one. If you don't feel the need then don't.

tommystrat Loc: Bigfork, Montana

I have a Nikon camera (D7100) with 2 card slots. The primary one (Slot 1) became nonfunctional when the locking mechanism broke, and I was told by Nikon it would require major surgery to replace it. Now I have a camera with one slot, and that works for me just fine. The only problem is that I cannot seem to upload software updates to the camera since it apparently requires the use of a card in Slot 1 to do so. Oh well...if anyone has any ideas how to do a software upload without using Slot 1 I would be delighted to hear about it. Please message me if you can help. Thanks!!

drklrd Loc: Cincinnati Ohio

I think it obvious .. A Pro needs a backup while an amateur may not. I need a backup as I have had cards fail from camera to computer. Worked well in camera but would not boot in computer. I need backup as I shoot things you cannot reshoot.

Festus Loc: North Dakota

It's because some of these so called pros can't shoot with one slot. Because they need to take 1500 shots to get 15 keepers!

PH CIB

I need two slots and two SD Cards because I have Dementia....and besides God mandated two of everything on the Arc !!!

rmalarz Loc: Tempe, Arizona

and two circles with a snap on top*.
--Bob

*-if one remembers the "In Living Color" film critics Blaine Edwards and Antoine Merriweather.

BlueMorel Loc: Southwest Michigan

That's why they get paid the big bucks! Not too many artists can slap their brushes on the canvas without touching up. Sometimes the shot not taken is the regret of a shoot - we've all had them!

throughrhettseyes Loc: Rowlett, TX

It's just the phobia of the failing SD card. XQD or CF cards are very reliable. There have been very few failures with them than the common SD card. So yes if you have a camera with only 1 SD card slot and you do weddings or events than you really need a camera that will back up the primary card. But past older photographers did just fine with multiple CF cards in there pocket with very little failure.