Photoshop comes preloaded with Filters whichever version you are using. You will find the Spherize filter in all versions. What do you use it for? It does have some uses, but why not for just some plain fun or for a special effect. It's really easy.
First we need a free stock image. You can download this image from here
Its mine
After using the Spherize Filter with a tweak the flowers look bigger.
Step 1 : Click the Elliptical Marquee to select it.
Step 2 : Press SHIFT and draw a circle. It will be a perfect one. Don't worry if it is not dead centre.
Step 3 : Use the UP, DOWN, RIGHT and LEFT ARROW KEYS to move the circle till it is approximately at the centre.
Step 4 : Go to Select>Modify>Feather.
Step 5 : Set a high Feather Radius of say 150. Click OK.
Step 5 : Go to FIlter>Distort>Spherize.
Step 6 : The Spherize dialgue box appears. By default it is set to 100 for Amount and Mode Normal. Click OK.
Press CTRL+D to deselect. The flowers looks much bigger now than they actually are in the original photo. That was easy I think.
I have opened this image in photoshop. It is a free stock image which you will find here
It belongs to aegipan
Draw a selection with the Elliptical Marquee. It can be a circle or even an oval. Move it into place with the ARROW KEYS.
Give it a Feather Radius of 250. Click OK.
Go to FIlter>Distort>Spherize.
When the dialogue box comes up just click OK.
The image looks like this.
Just for fun press CTRL+F to reapply the Spherize Filter and see the effect. Press CTRL+Z to undo if you don't like it.
That's all.
Other photoshop tutorials are here
You can also look here