S40 record time with 512Mb card

I was testing out my new S40 with a 512 Mb memory card to video a squash game that I was playing. When I switched it on it said that I had 18+ minutes of record time. It appears that the camera video'd about 16 minutes and then switched itself off. When I switched it back on it said that it still had 2:01 minutes video time on the camera.

The batteries were fully charged before I started recording and when I switched it on again the battery meter still said fully charged.

I'm wondering why it didn't record the last 2 minutes of available space? When I look at the file size on the memory stick it shows 442,678 Kb for that file. I'm wondering if there's a limit to the file size? If there is you'd expect it to be a number to the power of 2 and not this size I see recorded.

Any ideas? Comments?

I'm no expert, but you will see a similar sort of thing when you look at the capacity of the hard drive on your computer. Some of the theoretically available space is taken up with partitioning and with the basic file structure of the disk.

If you use a memory card with more than one camera, or buy a new camera, then you will find more folders on the card and more "wasted" space. This is one of the good reasons to format a memory card before you use it in any particular camera for the first time.

In any event, the space quoted for a card will not be strictly accurate, as a 1GB card will be 1024 MB if I've done my sums right!

Good theory - that prompted me to test the remaining 2 minutes that the camera advertised and it was still usable and recorded a further 2 minutes of video. When I looked at the memory stick after that I could see that there was a small amount allocated for admin purposes but there was also another 40Mb used up by the 2min clip I'd taken. So I guess that there must be a file size limit when taking video.

My mem card has is a 500Mb one. Has anybody created a very large file/video with a 1Gb card? And if so what is the biggest file/clip that you've managed to create?