CATransition *transition = [CATransition animation];

    transition.duration = 1.0f;

    transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    transition.type = @"moveIn";

    transition.subtype = kCATransitionFromBottom;

    transition.delegate = self;

    [self.navigationController.view.layer addAnimation:transition forKey:nil];

    [self.navigationController pushViewController:photoWall animated:YES];