I am planning to buy the Shen-Hao TFC69-A, which is a view camera with full movements but with 120 roll film. I have a 4x5 camera, and a 180mm lens, so I am wondering what the crop factor is for using 4x5 lenses on 6x9, e.g. on APS-C, a 50mm full-frame lens is a 75mm equivalent (I believe, haven't used digital in while )? Hopefully, I would like to only invest in 4x5 lenses and mount on small boards which I can use between cameras. The Shen-Hao can accept lenses from 52mm - 190mm. Also, in terms of bellows, would I still be limited to the 190mm equivalent (so if the crop factor was 2x, then I would only be able to use 4x5 lenses up to 95mm) or could I use an actual 190mm 4X5 lens (I highly doubt it, but its worth asking )? Thanks!