Prompted by my own answer to "Photographs cannot be taken" with manual lens and wireless triggers with off-camera flash & in reference to How do I take the right exposure quickly with Nikon D5300 and old AI-S Lenses? & others...
Is there a good reason that my camera, a D5500, can't use the exposure meter with a manual lens attached?
Of course, it cannot read any data from the lens without the appropriate connections, but why can it not just measure what it can see?
It can focus based only on 'what it can see' so why not also measure the light?
Does this also apply to higher-end bodies, or is it true for any manual lens on any body?