  Microscopy enables detailed visualization and understanding of minute
structures or processes. While cameras have significantly advanced optical,
infrared, and electron microscopy, imaging nuclear magnetic resonance (NMR)
signals on a camera has remained elusive. Here, we employ nitrogen-vacancy (NV)
centers in diamond as a quantum sensor, which converts NMR signals into optical
signals that are subsequently captured by a high-speed camera. Unlike
traditional magnetic resonance imaging (MRI), our method records the NMR signal
over a wide field of view in real space. We demonstrate that our optical
widefield NMR microscopy (OMRM) can image NMR signals in microfluidic
structures with a $\sim 10\,\mu m$ resolution across a $\sim 235 \times
150\,\mu m^2$ area. Crucially, each camera pixel records an NMR spectrum
providing multicomponent information about the signal's amplitude, phase, local
magnetic field strengths, and gradients. The fusion of optical microscopy and
NMR techniques enables multifaceted imaging applications in the physical and
life sciences.
