I remember a time when all Steiner offered were large, military marine style porro prism binoculars. Since I was working the retail optics counter in those days, I had access to several models and used them for birding. The individual eyepiece focus (autofocus in Steiner lingo) was less than ideal for close in work, but not bad for the longer ranges I encountered on the prairie. In fact, I can still remember a beautiful Le Conte's Sparrow as seen in the field of view of the Steiner 7x50 Military Marine. Very impressive ... also very heavy, so I traded that one in for a more petite 6x30 Hunter model (now discontinued). The 6x30 Hunter was a premium grade porro and about as sweet a little bino as I have used.
Things are quite different today, of course. The
Steiner Birding Store says it all. Steiner has listened to birders and we now have some excellent roof prisms for birding in the Merlin and Peregrine. Now if I had a Peregrine those many years ago ...