Nikon Nikkor-SW 90mm f/4.5

Stop a wide-angle large-format lens down to an f/8 maximum and the corners of your ground glass go nearly black, which is the whole reason this f/4.5 exists. Nikon spent the 1970s and 80s building out a full large-format Nikkor line to chase Schneider and Rodenstock, and the SW series was their answer for the wide end. SW means super wide. By 1982 the catalog split the 90mm into two versions: a compact f/8 for travelers who wanted light and small, and this f/4.5, the bright one built for people who have to compose in the dark. On 4x5 a 90mm is a proper wide angle, the first focal length most interior and architecture shooters reach for, and the extra brightness throws enough light to let you actually see the edges of the frame while you focus.

What you pay for that is bulk. This is a big, heavy lump of glass in a Copal 0 shutter with an 82mm front filter thread, larger than most of the SW line, and it is noticeably larger and pricier than the f/8 sibling. Coverage is not the trade though. Both 90mm SW versions run roughly the same image circle, around 235mm stopped down to f/22, so the f/4.5 buys you a brighter screen, not more room for movements. That 235mm is generous on 4x5 and leaves real headroom for rise, fall, and shift before you hit the edge of illumination. Tilt the front standard up a tall building and you need the circle to follow.

Rendering is clean and contrasty in the modern multicoated way, not the lower-contrast look of older single-coated wides. Sharpness across the field is excellent by f/16 to f/22, which is where you live anyway for depth of field on 4x5. Wide open it softens at the extreme corners and there is some field curvature to mind, so treat the f/4.5 aperture as a focusing aid rather than a shooting stop. Color is neutral. Flare control is good for a wide of this era, but it has a large prominent front group, and against side light a compendium or proper shade still pays off.

The honest limitation is weight and the premium over the f/8. If you hike with a field camera and rarely shoot interiors, the f/8 gives you the same coverage in half the load and you will never miss the brighter screen outdoors. People still buy the f/4.5 for studio and architectural work, where the camera sits on a heavy tripod and bright corners save real time.

It runs a Copal 0 leaf shutter, so flash syncs at every speed up to about 1/500. For the long exposures common with small apertures and movements, rack the standards out and the bellows extension costs you light. Feed that extension into Zone Light Meter and it computes the bellows factor, which on a 90mm creeps in faster than people expect once you focus close.