Why decrease shooting capacity with same parameter set?

[igercelman]

I am using 10D with 1GB CF card. I use RAW+SmallNormal. CF card capacity was 161 shots until today. I do not change any parameter. I formatted CF card. 10D showed 975mb after operation. But shooting capacity decrease 146. I couldn’t understand why? Do you have any idea about than problem?

[Mirko]

The size of the file is the ISO dependant. The higher ISO has more noise and can be less compressed.

Mirko

[igercelman]

OK. You are right. My false info is fix file size in RAW format.

Thank you Mirko.