In studio circumstances you need a lot of artificial light on the wet plate process. Because the light is limited you have to work with an open aperture. When you focus in large format the dept of field is quite minimal. So the solution for this issue is to use a technique called scheimpflug https://en.wikipedia.org/wiki/Scheimpflug_principle that means by shifting and tilting the lens you can make diagonal focus planes. It’s a big challenge and it need a lot of concentration of the sitters to stay in their focus plane. Well done guys! Thanks for your visit and corporation on making your special family portrait.