Dynamic Preview Quality
ON1 Photo RAW makes extensive use of the GPU (video card) for all of its on-screen processing. Starting with ON1 Photo RAW 2019.5, there is an optimization to increase performance when brushing or making other adjustments on deep processing stacks or underpowered GPUs. If the preview performance is calculated to be too slow for effective brushing, the Dynamic Preview Quality engages and reduces the number of pixels on screen during brushing or other adjustments. When this occurs, the preview will appear slightly softer than usual. After each brush stroke or adjustment it will return to normal preview quality. This is similar to the fast panning feature. You can control the Dynamic Preview Quality feature in the preferences. It is located on the System tab and is labeled Preview Render. This slider ranges from Faster to Sharper. At the default setting, the preview can become somewhat blurry when needed. If you wish to avoid this, you can move the slider to the right, to the Sharper option. At the far-right position the Dynamic Preview Quality feature is disabled.