Wikipedia is one of the most visited websites in the world but, by the admission of some of its own volunteer editors, it suffers from a persistent problem - terrible pictures, particularly of celebrities.

It is so full of notable people with very old or unflattering photographs that there are even Instagram accounts dedicated to the very worst ones.

The problem arises because professional photographers who attend, for example, film premieres tend to work for big agencies: their work is copyrighted and you usually need to pay to reproduce it.

Wikipedia - which is largely sustained by volunteers - does not have a budget for that.

Some enthusiasts launched WikiPortraits, a project to recruit a group of volunteer photographers around the world and get them accreditation to attend film festivals, conferences and other events.

"Wikipedia has for the longest time had missing or poor quality photos of people," said Kevin Payravi, one of the project's founders.

"This issue has always been in the back of our minds as Wikipedia editors."

He spoke to the BBC from Austin, Texas where he and fellow founder Jennifer........

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