Shader challenge: maintain good contrast with scanlines + mask

Is it impossible to maintain good contrast and dynamic range when using masks and scanlines on a typical ~400 nit LCD?

I’m not willing to reduce the scanlines to less than a 2:1 ratio (visible:black). This is what you’d see on a consumer-grade CRT that’s been well-maintained and properly calibrated.

Challenge: come up with settings that result in good contrast while using 2:1 scanlines and a mask effect.

“good contrast” - white should appear as pure white, not off-white or some shade of gray.

Bonus points for using a mask effect that is visible at normal viewing distance.


We might need someone who could add HDR to Retroarch. On an OLED you can have a 700 nit white pixel next to 0 nit black pixel with HDR. Not 100% sure if this is the fix but might be worth considering. I recall hunterk said we currently don’t have someone who could add this to the program.


Yeah, that would probably do it!

Brightness isn’t as important as contrast ratio. 50 nits would be fine in a totally dark room. We really just need much better contrast ratios to do mask stuff without degrading the image. Scanlines are much more important. I’d rather have good scanlines and no mask than crappy scanlines and a crappy mask. :slight_smile:


Want to take a stab at this?

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Had crazy issues calibrating with madVR, 5 hours in a row because the damned program failed at the end every time lol. When I get more time I will check this out, probably from Wednesday next week.


I don’t think it can actually be done, tbh. This is one of those things where I’d be happy to be proven wrong.

2:1 scanlines causes such a reduction in brightness/contrast that there isn’t enough left over for the mask.

Instead, when using a mask effect we should just maximize the dynamic range of the scanlines, which gives us maximum headroom for the mask.