Fauxtography

A reader has just sent me this stunning photograph of sunset at the North Pole, with a crescent Moon hanging in the sky.

Wow! What an amazing sight!

But ... hang on a minute. Which planet are we on here? Certainly not Earth. There's something wrong; several things wrong in fact.

First, if this is the North Pole, how come there's water? I know we're suffering from climate change, but I didn't think it had got that bad. And where have the mountains come from? The North Pole is covered by relatively flat sea ice.

Then the Moon's all wrong too. It's way, way too big here. Despite the fact that the Sun is millions of times bigger, their different distances from the earth make them appear the same size in the sky. This is the case wherever you are on the Earth's surface.

Finally, the Moon shines because of reflected sunlight. If it was in this position you'd be lucky to see anything of its crescent. This is New Moon (when the Moon is almost exactly between the Sun and the Earth) and you can't see it for 2-3 days on either side of that phase.

Sorry to disappoint you, but this photo is a complete fake.

The Moon is a popular subject for fakery in photography. If you know just a teeny bit about astronomy - and it's basic common sense - you can pick up false Moons in all sorts of photographs.

Now, if it was just the Moon, pasted in to some landscape photo on a calendar, it wouldn't matter much. Unfortunately 'fauxtography', as it's called, pops up in other more dangerous places - photojournalism, for example. It's not unknown for photographers and image editors to 'tweak' images in order to make some incident look more dramatic. And ... gasp ... it's even used for propaganda purposes.

Photographers provide us with a stream of amazing images. Viewers - keep a critical eye open.