Objective image quality when using shaders

I’m using the medafan Sega Saturn emulator in retroarch. In the first hallway nn the first level if you walk until you hit a dead-end protected by red barrels. It’s about 10 second into the game. What’s the easiest way to send a save state? You want to pm me an email address?

If you have a MediaFire or Google drive or something like that I’d be pretty simple.

Idk, I’m not sure how people feel about sharing their emails, I can’t speak for @Nesguy on this though. Just my suggestion, lol.

Though, it being that early in the game he may just load it up himself without a save state 🤷.

I also looked around for a darker arcade game which was harder than I thought. Alien 3: The Gun, (a light gun game) is pretty dark. It is also a good check to see if the you are losing to much detail on the lower end of things.

So it turns out the gamma mode just needs to be changed to the right mode.

This game uses sRGB gamma mode (makes sense, it was a PC game too). Edit: I don’t know, actually. Compare this shot to the next one and take your pick :stuck_out_tongue: All the detail should be clearly visible now, although maybe not quite as bright as you’d like. Anything you do to make the image brighter beyond this is going to have a bad effect on the dynamic range as a whole.

If a game looks too dark or you’re having trouble making out dark details, check out Dogway’s preset suggestions in the shader notes for grade, might be some helpful tips there. Sometimes all you need to do is switch gamma modes, sometimes you need to also make an adjustment to CRT gamma.

Be sure to view this at full size.

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Okay so here’s the same thing with Dogway’s suggested settings for this game. It was produced in Britain.

SMPTE-C, gamma 2.8.


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Thank’s Nesguy. I’ll check Dogway’s notes and so more testing on my own. Those two shots you posted look very close to me.

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The luma fix for Saturn is only for 2D games as I could observe. Didn’t inspect all 3D games but the ones I did were correct in PC levels.


Updated my “best settings” as a result of the experiments done with Outrun. Scanline dark is now 1.25 and scanline bright is now 0.75.

Back to Outrun, lol.

Using my current settings, no adjustment to brightness.

Current settings, adjust brightness to -0.02


Nice tests you did in these posts :slight_smile: I definitely like the improvement on the clouds with your latest setting. I do see some drawbacks though when using this as a “system wide” shader change.

  • beamshape is materially different from the 1.00/1.00 setting (at least when using the 12.00/8.00 combo on the beamshape settings), which is about my favourite
  • raising scanline dark makes dark screens even darker by a) making the dark lines even thinner (more black in between) and b) it actually makes the colors darker, only a bit, but it does (checked with color checker, probably there’s some related auto brightboost for the scanline dark/bright).

This last thing isn’t so much of an issue for mixed brightness screens like outrun with some dark parts, some very bright, and a lot in the middle. But I noticed by switching back and forth between old and new settings that it causes games that have areas with mostly dark screen/graphics in there that the newest settings makes these even darker (as if gamma was too low).

I tested a bit, and it seems that the lowering of scanline bright to 0.75 does already 80% of the wished for change on the clouds. So doing a 1.00/0.75 combo makes the clouds look good and does not have the issue of darkening dark screens even further when using this system wide.

Personally I’m settling I think on a scanline dark/bright setting of 1.00/0.85, as it does seem to do a lot of good in the dynamic range system wide, without the drawback that some games with dark areas become a bit too dark. Why not 0.75? As that changes the bright scanline shape a bit too much for me, the lines become a bit too harsch in the bright areas. Also it’s a bit too bloomy for my taste when used for other emulated systems.

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Thanks for the feedback!

All of that makes sense, I was actually using 1.00/0.85 for a while. I do see the drawback with raising scanline dark. I also agree that the bloom can start to look a bit unnatural with a large difference between scanline bright and scanline dark… 0.65 is when you get hard clipping, so I settled on 0.75 as a compromise. However, 1.00/0.85 is fine and probably better for the reasons you mentioned. Eye strain is also a factor and there’s such a thing as too much dynamic range because of this.

Outrun seems to have an expanded range at the high end (whiter whites). A better solution for Outrun might be to use 1.00/0.85 and lower the brightness parameter in grade a few notches until you achieve the desired depth, as per my most recent example. I think this approach can be used for games that have a similar range.

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Trying 1.00/0.80 for scanline dark/bright. I think brightness -0.02 is good. I’m not really noticing much benefit from going any lower, all the detail is clearly visible in the second shot and the gradient looks good to me. Thoughts?

brightness 0.00 (default)

brightness - 0.02

brightness -0.04


Here’s what that Alien Trilogy screen looks like with the new settings:


Good, your filter is good, the most complete. But need with your permission 3 option imperative in the world of CRT screens. Jitter, Humbar…and…Distortion. If you add this you ave the filter, the standart. I want add but i dint know how to add distortion or hum bar or jitter.

And some games arcade and consoles, need the option to center the screen, is important, if me not wrong HLSL is the unique with that.

I will post here results with the this filter of course.


i try a bit, with this filter and jitter effect, hum bar and distortion.

The best combination here, a standar in all places.

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That’s one of the mask types that I would avoid, personally, as that pattern will result in uneven spacing of the “active” LCD subpixels, resulting in chromatic aberration/color fringing.

Unfortunately, I don’t have a lot of experience with MAME HLSL so I don’t know what mask types to recommend there. You can take the suggestions I posted in the CRT shader thread and apply them to MAME HLSL but the setting names and numbers will be different; it might take some trial and error.

When you see in live a screen CRT, you see the tree colors RGB in the pixel, and the space too. You and hunterk dominate this good, are boss, i am sure you can do it, maybe @hunterk told to you some things because he known HLSL shader. The screen of abobe is veery close to a real CRT arcade, i add best colors etc, but the mask is the good.

Yes, I understand all of that, but you’re failing to account for how the LCD subpixel structure interacts with the mask pattern. You should check out this post at @hunterk’s blog for more information on how the shader pattern interacts with an LCD’s subpixel structure.

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Yes i know how to some types of CRT look, about colors etc some things, but you are the expert how LCD screens interact with mask etc like hunterk member.

A simple RGB pattern doesn’t interact well with typical LCD subpixels, that’s what the magenta/green aperture grille pattern (as one example among many) is meant to address. You should check out the link above if you haven’t yet; it explains all of this in great detail and has a lot of good photos illustrating these concepts.