Schneider-Kreuznach — 90mm f/5.6 fast wide-angle lens for 4x5 view cameras, larger image circle
The Super-Angulon 90mm f/5.6 is a brighter, larger-image-circle alternative to Schneider-Kreuznach's long-running f/8 version of the same focal length, aimed at photographers needing a bigger circle for full 4x5 movements or use with rollfilm backs.
It follows the symmetrical wide-angle formula of the Super-Angulon family in a larger barrel than the f/8 model, housed in a Copal 1 shutter. Its bigger front element and image circle come at the cost of extra size, weight and a larger filter thread than the f/8 version.
The wider maximum aperture aids ground-glass focusing and composition in dim conditions, though depth of field and edge sharpness still favour small working apertures typical of symmetrical wide-angle designs on large format.
It is less common secondhand in the UK than the f/8 version and tends to command a higher price. Check for front element coating wear, confirm smooth iris operation, and verify the recessed lensboard and bag bellows needed for the shorter working distance.