[quote=102055]You have scaled the overlay in gimp using linear filter. If you zoom in, you will see that this results in a blurring effect and alters the appearance of the scanlines in an irregular fashion. In addition, I think this darkens the image more.[/quote]yes, i understand how linear filtering works, thanks :) I have shown screenshots with the end result. The scanlines are fine for me, especially at my preferred brightness.
[quote]It may not be noticeable except when vertically scrolling, when it can be very distracting. The moire effect you describe fits the description of exactly what occurs when you use linear filter on the overlay in gimp or photoshop. You want to use “nearest” or “none” to avoid this.
[/quote]nope, as I say below, I got that effect when perfect 1px scanlines and integer scaling on – it’s totally a feature of my TV. using a ‘nearest’ filter would make it look awful – you get 2 pixel-thick scanlines every so often.
The games were designed with overscan in mind- the safe area is 90% of the vertical area on an NTSC CRT. So if you integer scale 240 by 5x to get 1200, you lose 120 lines on a 1080p display, or exactly 10% of the vertical area. So what gets cropped corresponds exactly to the overscan area, which is perfect. You don’t want to see overscan, do you? [/quote]
you’re confusing ‘overscan’ with the recommended ‘safe area’. eg, snes output 240 lines (standard NTSC signal), which comes out as:
0-6 (safe overscan area – can hide tiling garbage here)
6-12 (most TVs will show this)
12-228 (216 pixel ‘safe’ area – ALL tvs will show this. all important gameplay-critical stuff should be in here)
228-224 (most TVs will show this)
232-240 (safe overscan aree – can hide tiling garbage here)
so most games show important graphics only in the centre-most 216, but they will normally still render the playing field up to 224. given that most consumer CRTS (especially as we edge into the 90s) showed the centre 224 with increasingly tighter tolerance, showing the full 224 is more ‘realistic’ than just emulating a rubbish TV :) eg, see my sonic screenshot – there’s non-glitched graphics across the entire 224 lines.
in the mame/neogeo/mvs area, this is very different – these games seem to almost always have important information running up to the edges of the 224 lines – my theory is that arcade CRTs were more of a known-quantity, so they didn’t have to worry about consumer TV variance. a 5x integer scale for these games cuts into the scores, credits, health-bars, etc. see my windjammers screenshot for an example.
[quote]I think there’s an option to display frame rate under video settings[/quote]the frame rate feature doesn’t seem to work – said this above.