Conventional wisdom says you must turn off your camera when changing memory cards. Canon even does it for you when you open the battery compartment door.
But does it matter any longer? None of us turn off our computers when using their built-in card readers. More importantly, my D800 shows the green activity light and changes the number of photos on the top LCD even when power is off!. This indicates that the memory card is fully powered, even when the power is off.
Assuming he last image write is complete and the green activity light is off is there really any reason to turn the camera off?
I totally agree - and I try to remember to turn my camera off. But when I forget, it looks like there is nothing to worry about.
How can the camera determine the number of shots available (and show it on the top LCD) when the camera is off? The only answer: the memory slots are receiving power when the power switch is off.
Page 29 of the D800 User Manual says 'turn the camera off'. Is this just one of those warnings that is a carryover from the past when Off meant Off? It appears you need to remove the battery to actually turn the D800 off. I don't think that will make many happy.
Honestly, Nikon's engineers would be remiss if they didn't write code to handle that situation. So I expect it would work just fine. However, nothing is foolproof. I always turn off the camera because that makes sure the buffer is purged and all access pathways to the card are properly disconnected.
I used to think that too. But then I realized: the write buffer is purged in any event. If you turn the camera off, the green activity light stays on until the buffer is emptied. And if you leave the switch on, the same thing happens: the green activity light stays on until the buffer is emptied. The truth is: you must wait until the green activity light is off.
The card appears to be powered whether the switch is on or off - so why worry about it at all. It looks like turning the camera off makes zero difference with respect to the memory cards. Or to put it in more definitive terms: There is no evidence you are any safer with the power off - because the power isn't necessarily off.
I'm not sure the comparison to the card slot in the computer is accurate. On your computer you usually have to "eject" the card (or hard drive or thumb drive or device) before physically removing the card (or whatever). And if you don't do that, you get a nasty dialog box saying how you may have damaged… And almost always, everything is fine.
Until the one time that it's not fine.
I seriously doubt that Nikon engineers have programmed card removal status between shots. I think you have to power down to achieve that status. Admittedly, many of us have pulled out cards while the camera was powered and everything was fine. And that's grreat.
Until the one time that it's not fine, and maybe the card won't reformat properly.
So I power down.
Jon Kandel A New York City Nikonian and Team Member Please visit my website and critique the images!
These messages happen on PC's for two main reasons:
1) The delayed-write cache is still updating the card. You get a message on Macs and PC's since it's an asynchronous hardware function that is not directly controlled by the OS. There is no issue on the D800 so long as the green activity light is off.
2) A background task for Spotlight (Mac) or the Windows Indexing Service (Windows) can be updating the hidden system full-text index on the card. This can happen without warning, so waiting a predetermined amount of time is not sufficient. A D800 does NOT write this type of index information so it is not a problem.
The good news on the D800: You simply need to wait for the green activity light to stop. Then you can turn off the camera - assuming you actually can - which I highly doubt without removing the battery.
No, but I do use the "safe remove" every time I want to remove a card. I have lost many USB sticks and SD cards because I didnt use safe remove. I have removed CF cards from my D700 several times (by accident) and have never had a defect CF card - probably because it was done writing to the card. I do strive to switch it off, everytime