CATransition *shutterAnimation = [CATransition animation]; shutterAnimation.delegate = self; shutterAnimation.duration = 1.0f; shutterAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; shutterAnimation.type = @"cameraIris"; shutterAnimation.subtype = @"cameraIris"; [self.view.layer addAnimation:shutterAnimation forKey:@"cameraIris"];