iPhone Photography and Depth of Field

In photography, the wider the aperture of a lens (the more light a lens lets in), the less of the image not at the precise focus point will be in focus. This is known in photography as "depth of field."

As Apple has worked to improve night mode, they've also moved to lenses with larger apertures and thus higher light sensitivity - but as a result, depth of field is slightly reduced.

If you notice that areas away from the focus point of a photo appear sharper in photos taken with an older iPhone like the iPhone XS, you may be correct.

Looking at the technical specifications for both devices:

• iPhone 13 Pro Max, Wide lens: ƒ/1.5 aperture
• iPhone XS, Wide lens: ƒ/1.8 aperture

the larger aperture of the iPhone 13 Pro Max's wide lens (in photography, a lower number means a larger aperture, so ƒ/1.5 is a larger aperture than ƒ/1.8) means it will also have reduced depth of field as compared to the iPhone XS' wide lens.

This isn't a completely accurate representation, but it's a rough simulation of a comparison between the two, created using the tool at the website http://dofsimulator.net.

Say you focused on a model standing nine meters from the camera; the diagrams below show approximately how much of the image would be in perfect focus based upon distance:

iPhone 13 Pro Max:

iPhone XS:

If the model is further away, twenty-five meters, you can see that for the iPhone 13 Pro Max, objects closer than about 9.5 meters would start to blur:

For the iPhone XS, objects wouldn't start to blur until they were closer than about 8.5 meters:

The cameras in iPhones are merely photographic tools; whether it's an iPhone or a $3000 professional camera with a $2000 lens, for best results you need to work within the optical parameters of the system you have in hand.