There is no such control panel in Mac OS.
Unless there is something wrong with your system, your built-in camera is automatically is in focus unless you are closer to the camera than about 4 inches. My initial guesses are too little light or not enough broadband speed. However, let's first eliminate the possibilities that are easiest to correct.
• Carefully check whether there is a smudge or dirt smear on the camera's lens opening at the top of your MBP's display. If necessary, gently wipe it clean with the cloth that came with your Mac.
• Always use good (means very bright) light for best pictures. More info: http://support.apple.com/kb/HT3097
(The new Macs have changed the name from iSight to FaceTime or FaceTime HD camera, but the same info and troubleshooting applies regardless of the name for the camera in your MBP.)
• To determine whether the problem is ONLY with Skype video, make short video test recordings with QuickTime Player and iMovie. Play them back to see if the Apple apps have good video quality on playback. If so, we can concentrate on possible help for Skype.If nothing above fixes your problem, you can try the following steps to try to identify the underlying cause of your trouble so you will know what to fix.
(1) Restart your modem, router/wireless access point (if you use them), and then your Mac. Let each device's self-test complete before you start the next one. Then test Skype again.
(2) To be sure your ISP is delivering at least Skype's minimum recommended broadband speed (1Mbps down / 256 kbps up), check your broadband speed no other apps running. You can use a site like http://www.speedtest.net
(3) If your Mac's Skype images were better before you applied the 10.7.4 update when using the same Skype software in the same position with the same lighting, first verify that the Skype version you are using is the latest one compatible with 10.7.4.
(4) If you are using the correct Skype version and are still having trouble, use Disk Utility to repair permissions.
Then download and apply the 10.7.4 Combo Update: http://support.apple.com/kb/DL1524
Repair permissions again immediately following the system restart that completes the Combo update.
(5) If the Skype problem persists but your camera works with Apple apps, Skype's comprehensive support system should best be able to help you use their product with your system.
Start here: https://support.skype.com/
You can also search or post for help with your problem in Skype's dedicated Skype Discussions for Mac. The Skype users who post there may have already solved the same problem.
If no other Skype Help works, you can even sign in and ask for email help directly from Skype's Technical Support people.
(6) If all else fails, contact your Apple authorized Service Provider to have your Mac professionally checked.