Got this lens from the Camera Show last Sunday on an impulse. It's a large format lens that covers a 4x5 view camera. As is usual with large format lenses, the maximum aperture is rather small at f7.7 but it's quite normal for large format. A 12 inch lens is equivalent to roughly 300mm, which is very long. It needs long tube and very long hood, and as a result, the lens is more than two feet long on the camera and it looks ridiculous. But hey, photography has no fear, or shame :)
Without a long hood, this lens is not usable wide open; it will look all white out with nearly no contrast at all. A proper lens hood makes it usable af f7.7, but still, contrast is low. The minimum focus distance is VERY long at probably 5 to 8 meters. The first three pictures were shot using an extension tube. The lens is a very difficult to use. Hand holding it is next to impossible so I put the camera on tripod. Patience is mandatory.
I quite like how the lens renders pictures, especially the out of focus area. The lens is quite sharp at f7.7 and becomes very sharp stopping down to around f11, and at this aperture, contrast improves quite a bit too. Not too bad for a lens this old.
All pictures below were taken with the Dallmeyer Dallon 12 inch f7.7 and Sony A7.