Shot a series of photos at grandson's first birthday party with my D90. When I put the memory card into computer to download to Lightroom, there were no images from the entire session on the card (a 64 GB PNY). Images taken the previous evening were on the card, and after putting it back in the camera, images taken subsequently were properly recorded onto the card. Ran file recovery software on card, and it found no images from that session, although it did pick up old, previously deleted images from other sessions in the past (so the software was working). Camera is set to lock up if no card is in camera. During the session, I was checking the rear LCD to confirm exposures since I was using compensation to deal with strong backlighting. On several occasions I redisplayed the last picture taken to show it to my daughter. However, I don't remember if I ever cycled back to pictures taken earlier than the last one when doing a redisplay.
My questions relate to what went wrong, and how do I prevent it happening in the future. Will the camera seem to be functioning properly even though it is not writing to the memory card--should it have shown error message? Is there a setting that would prevent camera operation if writing to the memory card fails? Does the LCD read from the card, or the buffer? Does the last picture stay in the buffer until overwritten, so that redisplay could read it from there, even though it was not actually stored on the card? If the camera is not successfully writing to the card, why doesn't the buffer fill up and shut down operation like when a number of shots are taken in rapid succession? Is the camera's firmware supposed to check for successful storage before deleting an image from the buffer?
Since the images don't appear to exist, there's nothing I expect to be able to do about recovering them. However, I don't want this to ever happen again. Can the camera be set to lock up if images are not being written to the memory card? If I frequently scroll back through previously shot images will this be a reliable way of indicating that the camera is recording the pictures as it should? Are there any other indicators I should be looking for that would warn of such a problem?
Tried Nikon Technical Support, but all they said was that PNY cards are not approved and 64 GB cards are not approved. They did not respond directly to any of the questions I raised.
If anyone on the forum has insight into what was going on, I would appreciate their input. Thanks for your help.