I'm currently testing a digital SHG. This is based on a Carton 100mm f13 objective and a 60mm f13 Littrow spectrograph fitted with a 1200 l/mm blazed grating.
An ASI 174MM USB3 fast frame camera (laptop=MSI C, 16Gb memory, 500Gb SSD) collects the spectral data. Tests so far indicate a >400fps with a ROI 1930 x 48 pixel.
The basic design was evaluated using the SimSpec SHG spreadsheet
This SHG should have the ability to record solar images at any visible wavelength with a bandwidth of 0.24A.
My recent book "Imaging Sunlight" gives all the necessary info.