The 150mm RB soft focus lens covers 4X5 - these are great soft focus lenses once the learning curve is over and are currently on Ebay, brand new, at amazing prices from a Japan camera store. I bought 2 and they are in orginal unopened box - great buy for less than $140. Using a front from an old Pro S it is relatively easy to make a mount that allows the shutter to be fired and cocked. I believe there is an article on the Large Format forum explaing how to do this.