When a fish looks up from under the water, it is generally thought that they would see an ultra-wide angle hemispherical image. This is caused by the refraction of light through the water and is known as the Snell’s Window effect. That’s why any ultra-wide camera lens is known as a fish eye lens, as it produces a similar effect, an extreme visual hemispherical distortion. You get the same sort of visual by looking through a peephole in a hotel room door, the image you see looks like it is wrapped around a sphere because the lens is small and steeply curved.
So what if you want to duplicate this effect in Adobe’s Photoshop? There are actually a few ways to do it, but if you are working on a single layer, by far the quickest and simplest is the Spherize Distort Filter.
Open an image and choose the layer you want to create a fish eye effect on. From the top menu bar choose – Filter, Distort and Spherize to bring up the spherize window. There are only a few options, a slider to change the size of distortion and an option to change a spherical distortion to just horizontal or vertical, these latter two make the image look like it has been wrapped around a horizontal or vertical tube, but we’re going to concentrate on the far more interesting normal option that wraps the image around a sphere.
The preview window shows how altering the amount slider change your image, zoom your preview right out so you can see the whole image and see how sliding the amount back and forth gives you more extreme effects. For a fish eye lens look, you will probably need to go all the way to 100%. The filter will automatically create a fish eye lens that touches the edges of your canvas, if you want the effect to change a smaller area, as always with Photoshop, just use the selection tool to choose a smaller area within the image and the filter will create a fisheye that touches the edges of that instead.
If using 100% distortion is still not enough of a fish eye effect for you, just apply the effect and then repeat the process, I find applying 100% twice gives you an approximation of the sort of image you would see looking through a door peephole, but experiment and combine effects to get the look that you want, you can even combine the spherical and vertical or horizontal filters to give a distorted sphere effect.
