In hierarchical galaxy formation models , galaxies evolve through mergers and accretions .
Tidally-disrupted debris from these processes can remain as diffuse , faint structures , which can provide useful insight into the assembly history of galaxies .
To investigate the properties of the faint structures in outskirts of nearby galaxies , we conduct deep and wide-field imaging survey with KMTNet .
We present our observing strategy and optimal data reduction process to recover the faint extended features in the imaging data of NGC 1291 taken with KMTNet .
Through the dark sky flat-fielding and optimal sky subtraction , we can effectively remove inhomogeneous patterns .
In the combined images , the peak-to-peak global sky gradients were reduced to less than \sim 0.5 % and \sim 0.3 % of the original B - and R -band sky levels , respectively .
However , we find local spatial fluctuations in the background sky which can affect the precise measurement of the sky value .
Consequently , we can reach the surface brightness of \mu _ { B, 1 \sigma } \sim 29.5 and \mu _ { R, 1 \sigma } \sim 28.5 mag arcsec ^ { -2 } in azimuthally averaged one-dimensional surface brightness profiles , that is mainly limited by the uncertainty in the sky determination .
These results suggest that the deep imaging data produced by KMTNet are suitable to study the faint features of nearby galaxies such as outer disks and dwarf companions , but unideal ( not impossible ) to detect stellar halos .
The one-dimensional profile revealed that NGC 1291 appeared to have Type I disk out to R \sim 30 kpc with no obvious color gradient and excess light due to a stellar halo was undetected .