Want to add funny to your photobooks? Then a study of the portraits of comedians throughout the ages might just be your thing.

The National Portrait Gallery's new exhibition Comedians: From the 1940s to Now features contemporary British stars in all sorts of provocatively funny mock-ups.

From Johnny Vegas holding his belly in the style of the very famous and much-used image of Demi Moore clutching the underside of her pregnant belly to Sacha Baron Cohen mocked up as Michael Jackson, the portraits are an irreverent look at what makes people funny.

It's not just the comedians photographed that are the big draw, but also the photographers behind the pictures, which includes such luminaries as Annie Leibovitz, Bill Brandt, Karl J Kaul and Lewis Morely.

Clare Freestone, the NPG's associate curator of photographs, told the Guardian: "This display gave us the opportunity to highlight a group of people that have always been held high in public affection, with their performances often creating national talking points."

The show runs until January 8th 2012.