When your iris changes in size from light why does does the area we can see not change?
In: Biology
Every part of a lens makes every part of the image. This is how [pinhole cameras work](http://questgarden.com/127/71/9/110611112530/images/pinholeprinciple.jpg). Larger lenses simply mean more light gathering. This is why if you mask out half the lens on you camera, the entire image is still seen—just darker. (If you test this, make sure you are masking out your lens on the lens surface, not on optical glass *in front of the primary element*.)
To my point, [watch this guy murder a lens](https://youtu.be/YcZkCnPs45s) with a crab claw, and the lens still works perfectly. Albeit probably just a few % points dimmer.
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