When you need to gap some distance or compress it. This lens is often used in landscape, alpine photography and for architectural details. The newest version comes in SB 51, which reduces the size of the lens per se in your photo bag. Plus the 51 mm can be used for complementary tilt adapters.
New Version with Short Barrel 51
It is often overlooked that landscape and architectural photography is not automatically equivalent to wide-angle photography: Often, detail shots enrich the meaning of an image path and topographical features also require the use of longer focal lengths. For these subjects and requirements, the HR ALPAR 180mm rounds off the ALPA lens portfolio. Since the use of long focal lengths usually leads to very low camera inclinations, its image circle of 80mm in practice is easy enough, especially as the resolution remains almost constant over the entire image field. With a weight of less than one kilogram, the HR ALPAR 180mm remains easy to transport and, with an aperture of 5.6, delivers perfect performance even with an open aperture.