This creates visual distortion that is distinct and is often used in creative photography.
What Makes a Fisheye Lens Ultrawide?
A wide-angle lens can capture an image that is about 100 degrees wide.

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How a Fisheye Lens Works
All DSLR lenses except fisheye lenses are referred to asrectilinear lenses.
This is because light travels through the lens in a straight path to the image sensor.
This creates the straight lines you see in most photographs.

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This is the very effect that makes these lenses so popular.
That first fisheye lens had an 8mm focal length and an f/8aperture.
There are, however, two approaches to photography with a fisheye lens.

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The other group of photographers uses a fisheye lens specifically to capture the distortion the lens creates.
Another creative use for a fisheye lens is to take pictures with the lens pointing straight up.
This is useful in cityscape photography or even in landscape photography.

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One more, slightly obscure use for fisheye lenses is inmobile photography.
Post-Processing for Fisheye Images
Post-processing can play a couple of different roles in fisheye photography:

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