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Also, an old trick from the view camera days photographing skyscrapers with maximum rise on UWA lenses such as 65mm (equiv. to around 18mm in FF format):
It somewhat goes against logic, but tilt the lens opposite the plane of the subject, in order to allow more of the image circle to cover the sensor (or film) rather than using the peripheral area at the edge of the image circle which is always the poorest resolution and darkest (penumbra). This maneuver throws a significant amount of the image out of focus, so use maximum (or near) depth of field to cover the loss off sharpness. With DSLR lenses, this might mean stopping down to f/16 or f/22.
You need to carefully jockey the tilt/aperture combination for maximum benefit. It may require adjusting the lever of the camera body due to distortion in the image plane due to the tilt being introduced.
This technique is the opposite of the Scheimpflug Rule of tilting the lens to obtain the greatest DOF along a flat plane, ans is most often used in portrait photography to define an extremely shallow DOF.
A little tilt goes a long way! Using LV, you can see the edge of the image brighten up when "reverse-tilt" is introduced. Use the minimum amount and readjust the focus each time.
Here's a quickie diagram showing the lens on the right, the projected image circle, and the sensor on the left.
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