There are different ways to take video on the k-01 one with the dial on movie mode, and the other by choosing the red button to toggle video. I had read in previous video threads here to select my iso, aperture, and shutter speed in M and record from that which is what I have been doing since by simply hitting the red button. The problem with filming in manual is that it continues to adjust the exposure.
All that you need to do is set your dial to movie. Once set you can select your 3 peramiters and boom they are set and wont adjust regardless of auto focus or manual focus!
I am so glad that I payed with this today since I bought the samyang 16mm 2.0 for video and now I can use it properly.
Here is a video of the 2 different methods to video with your k-01 first the wrong way as I have been doing for months, and second the correct way.