  We introduce our new code MYOSOTIS (Make Your Own Synthetic ObservaTIonS)
which is designed to produce synthetic observations from simulated clusters.
The code can synthesise observations from both ground- and spaced-based
observatories, for a range of different filters, observational conditions and
angular/spectral resolution. In this paper, we highlight some of the features
of MYOSOTIS, creating synthetic observations from young massive star clusters.
Our model clusters are simulated using nbody6 code and have different total
masses, half-mass radii, and binary fractions. The synthetic observations are
made at the age of 2 Myr with Solar metallicity and under different extinction
conditions. For each cluster, we create synthetic images of the Hubble Space
Telescope (HST) in the visible (WFPC2/F555W) as well as Very Large Telescopes
(VLT) in the nearIR (SPHERE/IRDIS/Ks). We show how MYOSOTIS can be used to look
at mass function (MF) determinations. For this aim we re-estimate stellar
masses using a photometric analysis on the synthetic images. The synthetic MF
slopes are compared to their actual values. Our photometric analysis
demonstrate that depending on the adopted filter, extinction, angular
resolution and pixel sampling of the instruments, the power-law index of the
underlying MFs can be shallower than the observed ones by at least 0.25 dex
which is in agreement with the observed discrepancies reported in the
literature, specially for young star clusters.
