What we learn from the comparison between ISOCAM 15-micron & Spitzer 24-micron source counts.

The Spitzer Space Telescope is now providing new insights into the IR population contributing to the CIRB, in particular with the MIPS 24-µm band. The question raises on how to compare them with the previous ISOCAM counts at 15-µm. In this work, we present the 24-µm predictions, inferred accurately from a phenomenological 15-µm based model. We will show how extrapolating the ISOCAM populations at higher z, we can explain almost all the 24-µm sources.