ISO Affects Card Capacity?

[Imagebuffet]

I just discovered that when I change my Canon 20D's ISO between 800 and 200 or 100, the capacity of my 8 GB card changes. At ISO 800, I show a capacity of 482 RAW+small fine JPEG. At ISO 200, the capacity is 515. At H (3200), the capacity is 427. At ISO 100, the capacity is 521.

Does anyone know what is happening to cause this?

[AndrewCCM]

Interesting. I do know that it is just a mathematical calculation (using compression guesstimates as a factor) the the 20D is using (not often accurate). The more recent bodies seem to be a bit better at that.

[Collins]

Originally Posted by Imagebuffet

I just discovered that when I change my Canon 20D's ISO between 800 and 200 or 100, the capacity of my 8 GB card changes. At ISO 800, I show a capacity of 482 RAW+small fine JPEG. At ISO 200, the capacity is 515. At H (3200), the capacity is 427. At ISO 100, the capacity is 521.

Does anyone know what is happening to cause this?

The added signal noise "bloats" the file size at higher ISOs. So as you are adjusting the ISO, the camera changes the calculation of how many remaining shots based on that.

[LoungeLizard]

bing bing bing...Collins has it!