Even SPF 50 does not block ALL of the sun's rays, so you can still get tan while wearing SPF 50. It will just be a slower process than if you use a lower SPF sunscreen.
Whether you will get tan also depends on your skin type. Some skin types are more prone to burning or staying the same, while others are more likely to tan easily, even with sunscreen. Whatever your skin type, wearing sunscreen is still vital.