Yeah you should never go past 50 on any settings. You need to expose better remember your ISO is baked in so by pulling up the exposure you will just introduce more noise and banding your stressing the DNG this is video not photo's. Watch those highlights too, otherwise you lose color detail. Just because its Raw doesnt mean you can work miracles in post. WYSIWG turn on zebras and use the waveform when you shoot, expose correctly and a little work in post will shine. Dont be afraid to use high ISO'S its better than pulling up the exposure in post.