The welcome capacity increase and falling price made sense.<\/p>\n
\nWith an empty 2 gB card<\/i><\/center><\/p>\n
The 5D continues to dutifully reports room for 120 RAW pictures on a blank card, yet the other day I again noticed how low that estimate is. Obviously, the size of RAW files will vary depending on the scene, but the difference I noted is anything but insignificant.<\/p>\n
Apple’s Disc Utility reports available space of 2.039gB on a formatted 2gB Extreme IV card, so that means Canon is assuming an average file size of almost 17mB per image in computing the above count. Nice that they use so large a size as it means they are erring on the side of safety.<\/p>\n
Here’s the scoop:<\/p>\n
<\/center><\/p>\nThat’s actually 140 images plus a count of two for the containing folders. And there’s still 350mB of free space left! Do the numbers and you come up with a capacity of 171 pictures, or 42% more than that original estimate. Of course, this will vary with the scene photographed, as more detail and color translates to a larger picture file size.<\/p>\n
Now that’s a ‘feature’ I can handle any day.<\/p>\n
Follow-up:<\/b><\/p>\n
Check Comment #1 for a very interesting discussion of some of the underlying reasons for varying file sizes.<\/p>\n
The pictures I was writing about in this case were studio photos taken with studio flash with just the subject’s eyes critically sharp (the 85mm Canon f\/1.8 lens was used and 18″ x 24″ prints were a breeze to make and superb in every way) and everything else pretty much out of focus, so it seems the low ‘sharp content’ correlates with the small file sizes. The 10mB file above was a blank where I pressed the button before the flash was ready to fire, so that would appear to be the base file size of a 5D image. The Comment suggests that, for identical subjects, two lenses of like focal length will result in the one with higher micro-contrast generating a larger file size – an interesting ‘test’ method for this variable.<\/p>\n","protected":false},"excerpt":{"rendered":"
A welcome ‘feature’ of the 5D. I mentioned a while back that I was moving to 2gB cards in the 5D, from the 1gB I started with. The welcome capacity increase and falling price made sense. With an empty 2 gB card The 5D continues to dutifully reports room for 120 RAW pictures on a … Continue reading The real capacity of storage cards<\/span>