NGC 6611 is the massive young cluster ( 2 - 3 Myr ) that ionises the Eagle Nebula .
We present very deep photometric observations of the central region of NGC 6611 obtained with the Hubble Space Telescope and the following filters : ACS/WFC F775W and F850LP and NIC2 F110W and F160W , loosely equivalent to ground-based IZJH filters .
This survey reaches down to I \sim 26 mag .
We construct the Initial Mass Function ( IMF ) from \sim 1.5 M _ { \sun } well into the brown dwarf regime ( down to \sim 0.02 M _ { \sun } ) .
We have detected 30 - 35 brown dwarf candidates in this sample .
The low-mass IMF is combined with a higher-mass IMF constructed from the groundbased catalogue from Oliveira et al .
( 64 ) .
We compare the final IMF with those of well studied star forming regions : we find that the IMF of NGC 6611 more closely resembles that of the low-mass star forming region in Taurus than that of the more massive Orion Nebula Cluster ( ONC ) .
We conclude that there seems to be no severe environmental effect in the IMF due to the proximity of the massive stars in NGC 6611 .