your contrast may be too high. if you set it up only using the above white bar just before clipping, you can’t stop there (as 100% will always be too green and you can’t adjust your HIGHS to correct the whole grayscale). Check for discolouration in the step pattern and I guarantee you’ll need to lower the contrast. After doing so, grayscale will be more even and your controls won’t throw everything out of wack.