Phil has provided an excellent tutorial on making a realistic Golfball in Photoshop.
1. Make a new canvas. Here, I used 800 x 800 pixels, 72 dpi, RGB, background
2. Invert your background to make it black
2. Make a new layer
3. Use your circular marquee to draw a circle and fill it with white
4. Make a new document, 20 pixels x 20 pixels, RGB, background
5. Use your circular marquee to draw a circle and fill it with black
6. Edit: Define pattern (call it Dimples)
7. Go back to your original document (Ctrl-Tab) and make a new layer
8. Ctrl-click Layer 1 (the white circle you created) and press Shift-Delete to bring up your Fill options dialogue
9. Select Pattern, and fill with your Dimples pattern
10. Press Ctrl-T to bring up Free Tansform and rotate this layer 45
degrees. Press Enter.
11. Filter:Blur:Gassian Blur 2.0 pixels
12. Now Ctrl-click Layer 1, and hit Ctrl-F to repeat the blur
13. Filter>Distort>Spherize 100%
14. Now we'll finish the map by creating the contour of the ball itself.
Press D to reset your palette, press X to invert the colours, and select
your gradient tool (G).
15. Select radial gradient, foreground to background and change the opacity to 50%. Make sure your original circle is still selected, and draw a gradient from the center of the circle to the outer edge
Now we have a successful map to apply lighting effects.
16. Create a new layer, hold down alt, and merge visible. This will be our rendering channel. Select all, copy, create a new channel, and paste.
17. Hit RGB composite, and go back to the merged layer
18. Press Shift-Delete and fill with 50% Grey
19. Now go into Filter:Render:Lighting effects
Now here's where the fun begins. you can create whatever lighting you like. For this one in particular, I used a spotlight and an omni light. Change your texture channel to Alpha 1 (the one we created) and set white is high and height 50.
20. Hit okay.
21. Now we'll delete the extra material. Ctrl-click the original circle layer, invert the selection, and hit Backspace. Good. It's just a little harsh. No sweat, we'll lighten it up a bit with levels.
22. Press Ctrl-L to go into levels, and drag the Black triangle on the gradient at the bottom of the dialogue up to 125. I also brought the grey point down to 1.30
22. Now we'll just finish it up with some layer effects. Hide the two
source layers, and double click the final render to get into layer effects.
Here I used the following...
Hard Light with Black
Distance 49 px
Size 62 px
Blending mode Color
Blending Mode Overlay
Angle 24 degrees
I also made the background white again.
Here is the final before touhups...