If Potato Shaders don't meet your "extra quality" needs, these are popular 1.8.9 alternatives for low-end PCs:
To get the best visual-to-performance ratio, adjust these settings in the menu: How To Install Shaders Into Minecraft 1.8.9 potato shaders 189 extra quality
Are you planning to use these for or general survival gameplay? If Potato Shaders don't meet your "extra quality"
void main() // ... frag_color = texture(texture_0, uv); potato shaders 189 extra quality
"Potato Shaders" come in a few variations. The most popular versions that include "Extra Quality" settings are usually: