How to get sharp photos from a wide-angle lens
It’s tempting to think that to ensure sharp images you simply set the lens to the minimum aperture and shoot away, but this isn’t the best approach.
There are loads of factors that can affect the sharpness of your images, such as the quality of the lens or the presence of camera shake, but the aperture you choose is the easiest one to control in the field.
Shooting at the widest aperture will usually give you reasonable sharpness in the middle of the frame, but the edges will often be much softer.
Shooting at the narrowest aperture will give you better depth of field, but the sharpness across the image can suffer because of diffraction.
Most lenses have a ‘sweet spot’ that will give you sharp results across the image, usually at around f/5.6 to f/11.