Most professional level digital cameras have two memory card slots instead of one – primarily as professionals cannot afford to lose all their money-making and goodwill making images in the unlikely event of a memory card failure.
The Olympus OM-D E-M1 Mark II and its new dual card slots:
As the camera is primarily aimed at still photographers rather than video, unlike the forthcoming Panasonic GH-5, only one of the SD card slots is super fast and compatible with the UHS-II standard.
If you wish to do 4K video or 60fps burst rate in RAW, you will need a compatible fast (“UHS class 3”), high capacity UHS-II SD memory card – not all work – check the compatibility – Olympus recommend Sandisk Extreme Pro SDHC / SDXC UHS-II Card or Toshiba EXCERIA PRO™ UHS-II SDXC/SDHC Card – see their compatibility tables here.
These cards are not cheap, for example a 64Gb UHS-II card will set you back around $AU200 and you can double that for a 128Gb card in early 2017.
The E-M1 Mark II offers various file saving options if you have 2 cards:
- “Standard” will record to the specified card – allows movies to one card and stills to another card
- “Automatic Switching” will automatically switch to the second card when the first card becomes full
- “Dual Independent” will record to both cards according to the specified image quality setting assigned to each
- “Dual Same” will record identical files to both cards simultaneously
This is set in the Menu under cogs:H1:Card Slot Settings:Save Settings for still and cogs:H1:Card Slot Settings:Movie Save Slot
The Dual options each have a sub option of whether or not you wish to have the ability to keep saving to one card even if the other card is full.
E-M1 Mark II play back options:
This is set in the Menu under cogs:H1:Card Slot Settings:Playback Slot.
Unfortunately this only gives you the option of slot 1 or slot 2 so the camera does not automatically “remember” your last playback slot that you can select by holding down the playback button while rotating the top right dial which could inadvertently lead you to accidentally deleting a RAW file in slot 1 thinking it was the jpeg file in slot 2.
Temporarily viewing images on the card which is not the default playback card:
- press the playback button while rotating the top right dial and the screen will indicate which card slot it will use to playback
- unfortunately, as mentioned above, this is not retained once you take another shot, playback reverts to the default playback slot
Advantages of dual slots:
Insurance against card corruption, damage or loss:
The ability to save 2 physical copies of your RAW files simultaneously via the “Dual Same” mode is critical for professionals.
Some insurance against accidental deletion in camera:
If you are using the Dual modes and you delete an image or erase the card or re-format the card, it does not delete the image on the other card – of course, you can change the playback to the second card and then also delete that image but at least that requires effort.
Faster saving of RAW+jpeg rapid burst:
The ability to save RAW files to one card and your jpegs to another card allows faster burst rate buffer clearance and possibly less playback “blackout” after a burst while all your images get saved. The E-M1 II does not have live view visual blackout after a burst but you will have slowed burst rates after a long burst until the buffer clears, and saving to two cards can potentially reduce this issue somewhat.
Ability to automatically save movies to the UHS-II card and stills to the second card:
Just set saving option to “Standard” and then you can set the save slot for stills vs movie in that same menu area.
More capacity within the camera:
“Automatic Switching” allows the 2nd card to be used when the 1st is filled up (although you do lose the fast UHS-II capability with the second card slot.
Playback zoom when capturing RAW + small jpeg:
One issue with playback on all Olympus cameras to date has been that if you selected RAW+small jpg as your file save option, on playback, when you zoom in, you do not get to see the actual RAW captured detail, only the much less detailed small jpeg which in effect limits your zoom to perhaps 3-5x instead of the 10-14x to really check if your image is sharp.
Having the dual slots overcomes this as you can have RAW saved to slot 1 and small jpeg to slot 2 and when you playback slot 1, you view the full captured detail in all its glory and no longer have to wait until you get it on the computer to ascertain if it is sharp enough.
Ability to backup all images from one card to another in camera:
This is great if you are on holidays traveling the world and don’t have a mechanism to backup your images.
Just buy another SD card of same capacity but can be a slower, cheaper card, then in Playback menu, select Copy All and then choose the copy direction – make sure you get this direction correct – although it will not delete existing images on the destination card so that is a great safeguard!
Disadvantages of Dual mode:
The Olympus delete image option of simultaneously deleting the RAW and JPEG does not work if you are saving each to a different card.
It thus takes more than double the effort to delete an image off both cards or erase the two cards – you need to manually select the second card and then repeat the process, but perhaps this is a good thing!
You may accidentally delete an image from the wrong card if you forget the camera reverts back to the default playback card!
My firmware suggestions:
- add a 3rd option, “last viewed” to the cogs:H1:Card Slot Settings:Playback Slot so that one does not have to dig deep into the menu to keep your playback slot preference
- playback zoom should have an option to view the RAW file rather than a small jpeg if only a single card is used for RAW+jpeg – this should apply to all Olympus cameras whether one or dual slot designs.