We present an evaluation of the precision and accuracy of image-based radiochromic film dosimetry. A stack of radiochromic film FWT-60 was used to map a radiation field produced by an electron pulse from a Febetron 707 accelerator (dose rate around 5•1011Gy/s; maximum dose around 160 kGy). The three-dimensional dose distribution was obtained by a He-Nescanning-laser microdensitometer and using image segmentation and correction for non-linear response of films. Calorimetry and electron paramagnetic resonance dosimetry were used to verify the results obtained with a FWT-60 film.