I've noticed on Apple's comparison page, they are now mentioning that iPhone 11 Pro Max has 4x optical zoom (which it does not). They are also mentioning that iPhone 12 Pro Max has 5x optical zoom.
However, if you look at the fine details, it's mentioned that the iPhone 12 Pro Max has a 5x optical zoom RANGE, meaning that it can zoom out 2x, and zoom in 2.5x. I'm guessing that they are able to round 4.5x up to 5x optical zoom.
From iPhone 12 Pro Max's tech specs:
2.5x optical zoom in, 2x optical zoom out; 5x optical zoom range
Source:
However, if you look at the fine details, it's mentioned that the iPhone 12 Pro Max has a 5x optical zoom RANGE, meaning that it can zoom out 2x, and zoom in 2.5x. I'm guessing that they are able to round 4.5x up to 5x optical zoom.
From iPhone 12 Pro Max's tech specs:
2.5x optical zoom in, 2x optical zoom out; 5x optical zoom range
Source:

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