画質

1. Origins, structure, and basic meaning

• Structure: 画質, read がしつ, is a noun for the visual quality of an image or video.
• Basic usage: 画質を調整する changes quality to improve legibility; 画質を下げる explicitly lowers it to reduce file size.

2. Common pitfalls and similar expressions

• Neutral adjustment versus lowering quality
  • Both constructions take 画質を, but 調整する leaves the direction open and 下げる specifies a reduction.