[QUOTE=hunterk;22503]Yeah, you should just make retroarch run at your monitor’s resolution. 720p is usually okay on TVs but usually looks like garbage on PC monitors.
What’s happening is that it’s just scaling your 1280x960 up to 1080p anyway.[/QUOTE]
oops, I totally mis-worded that. I am indeed running retroarch at my montior’s native resolution, and my custom viewport is set to 1280x960 (on NES).
Should I make the overlay 1920x1080, or 1280x960? Something else? Neither one looks right to me.
I finally figured this out! With absolutely no prior knowledge of how to use graphics editing software, I finally did it. Turns out my scanline image was wrong. I started over and I made a simple 4 pixel tall image with 1 black line, 1 white line, 1 black, 1 white. Then I selected the image and tiled it across the 1920x1080 area. The transparency part was hard. I had to add a transparency layer, then navigate to the background layer (where the scanlines were), select all the white with the right tool, then use the color to alpha option.
It now looks PERFECT, with the opacity at 100% its identical to the interlacing shader! I can also adjust the lines within RGUI, which is cool.
The 1920x1080 overlay included with Retroarch in /effects/scanlines does not work right. I made a new one that looks right but I can’t figure out how to attach it.
Is there a way to attach images without them being resized?
oof, yeah, that one does look weird. I should probably go back through and check the rest to see if they’re similarly janky.
If you can’t put it on imgur or something without resizing, just zip it up and toss it on a file locker, like mediafire or dropbox or something.
i’m using a pc crt and 2560x240 super resolution and it looks like this
i adjusted the vertical focus to make the scanlines thinner tue day after i took this pic, but ANYWAY
can an overlay made to mimic these vertical dots be possible? maybe not so sharp probably
I think the first shot looks pretty great, FWIW. 
The second shot is a very blurry photograph of a CRT, and I wouldn’t use that as a reference for CRT shaders or overlays.
PC CRTs are great; you can make them as sharp or as low-res as desired. At 480p, the interlacing shader is almost identical to “true 240p.” For the low-res look, TVout-tweaks’ signal resolution parameter is very useful, and some of the CRT shaders can look pretty nice on a CRT monitor with some tweaking (Easymode comes to mind).
As I said, the second photo is very blurry and doesn’t accurately capture what a low-res CRT looks like at that distance. If you just want to add those vertical black lines, you can easily accomplish that with an overlay. Try this one:
However, this doesn’t look very CRT-like; it looks more like a low-res LCD grid IMO. What you really want is to recreate the RGB phosphors. To do that, you need something like this:
Note that I have not tested either of these, yet. I’m not sure how the overlays will look once scaled by the monitor, and I also have no idea if those RGB values will look good, you’ll have to adjust the color levels until you find something that looks good on your display. Also worth keeping in mind is that the CRT has it’s own phosphor mask, which might look strange with the overlay.
Also, if you’re going to use overlays, I recommend using a normal CRT resolution (1024 x 768 for example), because this allows you to add more vertical detail in the overlay. EDIT: you can use TVout-tweaks signal resolution parameter at any setting below 1024 to deal with scaling artifacts on the x axis.
EDIT 2: yeah I just tried the RGB one and it didn’t quite work. Maybe need to add more transparent black or white, and/or adjust the color levels or transparency levels.
