Actually, Graphics of any format were considered medium format in the old old days. Apparently, the film size was not the point, there were seemingly a million different roll film sizes, but handholdability that was the deciding factor. If it had to be on a tripod it was large format, even if it used really small film. Miniature format seemingly used motion picture film. It was only after everything other than 120 roll film was gone that those definitions changed. I have a book from 1960 where they still listed the 4x5 Speed Graphic in the medium format section.
Originally Posted by Roger Cole
For what it is worth, I think the Speed Graphic and its ilk were considered pack film cameras that could be converted to use other formats: sheet film, film plate, roll film, etc.