MiSTer FPGA Forum

Post your up close shadow masks pictures of your CRT So devs can get an accurate depiction of your CRT for future Shadow Mask filter developments. Post your TV brand / era .

Consumer Daewoo late 90's - early 2000's flat pane CRT

Great idea!

We should use some kind of standardised reference image. This would make both the comparisons, as well as the subsequent development of shadow mask filters a lot easier.

A pattern from the 240p Test Suite might work well; such as the SMPTE Color Bars & EBU Color bars:


Or the Color Bleed Check:


(I, [un]fortunately, do not own any kind of CRT).

Double Dragon (Arcade version) being displayed on a 14” Sony Trinitron via RGB Scart. TV is mid 90’s.

Shadow Masks are both dead simple and simple to create, just use this tool.

I think there are plenty of shots of common random consumer CRTs out there. If you want a certain look, just make it yourself, it's very easy. Albeit there are already so many minor variations out there on update_all, and what you can make is kind of limited, so someone has probably already made something similar.

The biggest difference I see between my oled 4k with masks + Custom filters and my CRTs is the black areas. On the CRT (Samsung GXE1395) you still get the RGB stripes in blacks and some subtle blending into it where as on my OLED they are black. Is there a mask option to carry the mask over true black areas? Maybe my greed driver is turned up too much too .

Any suggestions on scanlines + shadowmask + resolution to achieve this look? I am at 1440p but I am almost thinking I need to drop to 1080p to get closer to the RGB stripe per pixel of this.

FoxbatStargazer wrote: ↑Mon Dec 06, 2021 4:08 pm I think there are plenty of shots of common random consumer CRTs out there.

There are some, but most are of low quality or taken from a distance which makes distinguishing details impossible. That's why I've started this project: https://archive.org/details/crt-scr-v-0.1

This release doesn't have any consumer TV shadowmasks yet though, and not many close-ups. If anybody feels like contributing, please give me a shout.

Here's one from a modern (2000s) 14" Philips which I just got today (RGB from MiSTer)


Original Apple 2 composite monitor, courtesy of @thorr. Click for a zoomed in one


Amiga on Commodore 1084

Getting closer, is that offset RGB shadowmask possible in the 8x8 mask?

So I have done some experimenting here are some of my first attempts.

https://github.com/redsteakraw/Shadow_Masks

I think there's a misunderstanding surrounding the whole shadow mask deal; there's no fk*n way you can replicate any CRT.

The deal is to get close enough as a sensation, and get rid of those moribund... bulky things, as we'll all have to do with sooner or later, in order to preserve the games as close to what can be called 'authentic looks' in the future ahead.

flynnsbit wrote: ↑Mon Dec 06, 2021 5:23 pm The biggest difference I see between my oled 4k with masks + Custom filters and my CRTs is the black areas. On the CRT (Samsung GXE1395) you still get the RGB stripes in blacks and some subtle blending into it where as on my OLED they are black. Is there a mask option to carry the mask over true black areas? Maybe my greed driver is turned up too much too .

Any suggestions on scanlines + shadowmask + resolution to achieve this look? I am at 1440p but I am almost thinking I need to drop to 1080p to get closer to the RGB stripe per pixel of this.

The filter/shader that can do this well is the CRT Royale shader for Retroarch. But it requires at least 4K resolution for optimum results, a recent GPU (and compatible drivers), and quite a bit of tweaking.

lamarax wrote: ↑Mon Dec 06, 2021 8:50 pm I think there's a misunderstanding surrounding the whole shadow mask deal; there's no fk*n way you can replicate any CRT.

The deal is to get close enough as a sensation, and get rid of those moribund... bulky things, as we'll all have to do with sooner or later, in order to preserve the games as close to what can be called 'authentic looks' in the future ahead.

No misunderstanding here on my side. I know how shadow masks work.

heres some closeup PVM-3230 action


PVMs definitely have a look, like it or hate it, especially compared to consumer/trinitron CRTs

I guess I'm more saying that the Mister shadow mask is an extremely limited tool. You are hardly going to be able to replicate the subtleties of one mask vs another... just very broad things like "here's a bunch of tall rectangles in a pentile pattern" and "here's some color fringing" and people already built quite a few subtle variations on these, it after all takes minimal effort to just put something in yourself. And the resolution is way too low to represent a lot of these masks at their actual size. You aren't going to be "preserving" anything with such limited tools, really you get better results hinting at or suggesting a mask pattern rather than trying to replicate them 1:1. So this thread feels like digging up images of renaissance art and expecting someone else to replicate them in Mario Paint.

From what I am seeing in working with making these shadowmasks, the higher your resolution the better, but also the alternating off set masks like the JVC and Daewoo / consumer TV masks would be harder and require higher resolutions to do better. 720p is not going to cut it. Maybe 1440p or the retna display would yeild better results. Also the mask may not look good blown up to 55" on a huge screen unless it is subtle. The Trinitron / PVM style in line mask looks a whole lot more doable. Also to really do this right it may be better to have the R G and B mask be associated with the R G and B values of the pixels behind it. I tried making masks with RGB but they all look like ass. 720p resolutions need a no larger than 3 line mask which is near impossible. 1440 would be 6x6 and 5x 1080 would be 5x5. It may be better to just target a given resolution with the intended shadowmask.

Bump for the new v2 masks, have you had any chance to look into these Redsteak?

MikkyTee wrote: ↑Thu Dec 16, 2021 11:24 am Bump for the new v2 masks, have you had any chance to look into these Redsteak?

The system is far more flexible however I am being more and more convinced you will have better results at higher resolutions I haven't seen anything major yet but some of the sub pixel stuff seems interesting.