  Weak lensing studies typically require excellent seeing conditions for the
purpose of maximizing the number density of well-resolved galaxy images. It is
interesting to ask to what extent the seeing size limits the usefulness of the
astronomical images in weak lensing. In this work, we study this issue with the
data of the DECam Legacy Survey (DECaLS), which is a part of the target
selection program for the Dark Energy Spectroscopic Instrument (DESI). Using
the Fourier Quad shear measurement pipeline, we demonstrate that images with
relatively poor seeing conditions (around 1.5 arcsec) can still yield accurate
shear estimators. We do not find any correlation between systematic shear error
and the image resolution.

Cosmology and Nongalactic Astrophysics;Astrophysics of Galaxies