Usually when focusing a "normal" camera I try to select a point of focus about a third into the scene and try to get as much depth of field as possible, but with 5x4 camera I am getting confused, if I tilt the front board forward a bit it look's like I am getting more depth of field.
How can I be getting more depth of field than the lens design and aperture permit. Surely its constrained by physical parameters and not something that can just be adjusted or digital cameras would do it.
You can't and don't.
Start off with the understanding that there is no such thing as depth of field, what we call dof is the amount of unsharpness that we think is ok or that we can't actually see, the only part of the image that is really sharp is the part that the lens is focussed on. I think that I needed to get that in there, but now we can move on.
As
@thedistrictline line helpfully and correctly pointed out, camera movements do not and cannot increase depth of field, they simply(?) move the plane of sharp focus so that it is no longer strictly horizontal. The dof remains the same but when we move the plain of focus from the horizontal by swinging or tilting the lens we move that plane of sharp focus somewhere else, giving greater or less apparent dof than if the lens was straight.
Sounds complicated? It's actually quite easy in practice, just set up your camera and have a play, a lot of people find that just doing it is much easier to understand than the theory.
And when you've mastered that, introduce movements on the rear standard as well as on the front, assuming that your camera has rear movements, you will now have even more (much more) control.
Scheimpflug was a very bright lad, it's well worth looking up this principle in detail. The wiki page is helpful, but look at this one too
https://www.cambridgeincolour.com/tutorials/depth-of-field.htm
It's fissics innit?
