I have a NX1 with two lenses 16-50 f2 / 2.8 and 50-150 F2.8. They are great for photography and video give a picture quality that I love, the problem is that in video for manual focus ring approach is too hard. I do not have much money, so I'm looking for a relatively cheap lens, such as Porst Reflex Auto Color-55mm recommended in the EOSHD guide Do you think this type of lenses would be a good option would solve my problem or or is a better solution manual follow focus system like this amazon with my current lenses?.