CF card capacity

[Railman]

Took my camera(D200) out yesterday to an air show. I decided to shoot in JPEG fine as I could take more pictures than in Raw. The estimated number of shots shown on the camera was 118 for both a microdrive and an extreme3 CF card. when happily snapping away I managed to get just over 500 shots on each type of card. The camera is set to optimse images. Anyone any idea why the discrepancy in numbers.

Dan

[Canis Vulpes]

Nikon provide a pictures remaining count at worst case. JPEG compression is very variable, a totally white or black (noise free) or any simple image is compressed into a smaller space using the JPEG algorithm. More complex scenes such as grass or tarmac is not compressed as much due to JPEG being efficient with large areas of minimal detail. Aviation shots tend to have large areas of detail free sky so can be compressed well.

The counter will continuously update so if it shows 200 remaining and then you take a 10 aviation shots it may read 10 recorded and 197 remaining.

[Railman]

thanks for the info

[Canis Vulpes]

You soon get a feel for how many photos can fit on a card. I always shoot NEF on a 2GB card although the remaining counter suggests I can get 99 photos this is worst case again with no NEF compression. In reality I can get 195-205 photos per card as the compressed NEF's are 50% of an uncompressed NEF weighing in at approx 10MB.