Everything looks better in scanlines!

[TotO]

I was just thinking about that yesterday, how strange it is that some emulators offer this when the CPC monitor never looked like that.

Because it is the fast and easy way for looking "retro".
(as displaying things in green on sci-fi movies)

[arnoldemu]

I think it comes from arcade monitors where scan lines are more visible? Maybe more visible on 60hz than 50hz.

It is more visible on green monitors because there is less bleeding of colours between the electron guns and the brightness is less.

I think that because the cpc is a progressive 288p display then depending on vertical height there are lines which are not scanned, so there should be (in a perfect calibrated monitor) darker lines, but because of the r,g,b and the focus and the 50hz the horizontal scanlines are almost invisible.

For emulation it is quicker to put black lines, but this is not accurate at all. Doing a full filter takes more cpu time.

[TotO]

It come from the CRT mask technologies used for displaying pixels.
The CTM use a slot mask, so the beam raster scan and hilight colours when other monitors use an aperture grille, so the beam interlines increase the scanline effect (more visible at 60Hz, because interlines are biggest). PC CRT monitors usually use shadow mask.




Here an Aperture grille (licenced as Trinitron by Sony) close-up:



You can found this basic mask on most arcade monitors and NTSC TV sets...
It is why, arcade look better (at less in minds) with scanlines! 

[TotO]

Obviously, the GT85 monochrome monitor don't use colour mask... So scanlines are visible.

[KaosOverride]

I was just thinking about that yesterday, how strange it is that some emulators offer this when the CPC monitor never looked like that.

In the case of Caprice, for double resolution  there is a hardware double-height render mode. You draw the display with double width and single height, and hardware scale makes the rest. This is less CPU demanding printing a 2x1 display. Double work. For a 2x2 more CPU is needed, working 4 times more than low resolution mode. For low CPU systems and no hardware scaling the scanlines render is your friend, printing 2x1 but only even lines.

But this was 10 years ago, now we have enough horse power for full pixel printing.

What caprice needs for scanlines is odd lines a bit darker than even, and you have a nicer effect...

Also I'm aware that you are after a different and more accurate effect that the one I can get at an emulator, but I'm learning a lot of this subject and trying to do the best of caprice code (and for a raspberry host, so low CPU powered comparing with a PC)

[roudoudou]

hi, here we go again 
conversion for fullHD, grid effect, some photophore blend, a little glow. I must improve mode 2 patern

[Gryzor]

Really nice. Perhaps a little too strong, but mode 0 especially looks great if you don't put your face against the screen!

[roudoudou]

still working on new method
this one is nicer (energy distribution in fake photophores, obviously a little darker than fake RGB)

[Gryzor]

Yeah that's a bit too dark.

Now, who's going to implement all those nice filters in a Windows terminal?

[arkive]

Retro Virtual Machine has one of the best, easily configurable CRT implementations right out of the box. https://www.retrovirtualmachine.org/en/

You can also use the shaders in Retroarch on top of CPC emulation, or use Reshade to inject them directly into standalone emulators: GitHub - Matsilagi/RSRetroArch: (Curated) Repository of RetroArch and related ports for ReShade

[roudoudou]

RVM CRT emulation is far from a CPC monitor, if you think it's the best avalaible we are f*cked 

but i agree it's nice, funny and fancy, but every FX are not related to CPC monitors

[Sykobee (Briggsy)]

I think it looks good for the darker colours, but the bright colours are muted by the effect. A gentle bloom on the bright colours might be nice too.


Maybe we need some reference photos from real CPC monitors for a variety of loading screens and test patterns, to assist in the CRT effect development.

[arkive]

RVM CRT emulation is far from a CPC monitor, if you think it's the best avalaible we are f*cked 

Prove it It has specific options for GT 65 colour/mono.

Besides, not everyone uses Amstrad monitors, at least not these days. Mine look great on my Trinitrons.

[roudoudou]

proof is used to prove that something exists, so it's your job to prove that RVM can mimic CTM

Here is a closeup of a CTM MM monitor, good luck with settings 
in the meantime i will continue to do something that looks like real CTM/MM 

[eto]

Here is a closeup of a CTM MM monitor, good luck with settings 
in the meantime i will continue to do something that looks like real CTM/MM 

Can you share which program is displaying this test image?

[roudoudou]

Can you share which program is displaying this test image?

if you mean the mire => https://www.cpc-power.com/index.php?page=detail&num=16027

[eto]

Yes, this one. Thanks.

Unfortunately I can't compare the output of the MM to the RVM but based on your picture (which of course also cannot replicate the exact impression you have in real life) I think the RVM emulator is doing a pretty good job. One of the reasons why I prefer it over the others, as the "feeling" is closer to a real machine than the other emulators.

[roudoudou]

there is absolutely NO horizontal scanline on CPC because of the staggered photophores (see photo below, it cannot happend)

on your try, there is no blend between pixels => on the CTM/MM you have 5 RGB photophores for eight pixels, that's why mode 0/mode1 pixels looks like elipsoids and why mode 2 is blended

Plus photophore has a particular behaviour because of energy emission at different locations
RVM will never emulate a CRT with pixel FX, you need to mimic photophores and do RGB emission at different locations

photography courtesy of Sylvestre


last try with my conversion routine

[eto]

Thanks for the explanation. Now I understand better what you mean.

[arkive]

proof is used to prove that something exists, so it's your job to prove that RVM can mimic CTM

I'm not sure you realize how "proving" something works The onus is usually on the one challenging an assumption. But, thanks for the pic anyway, that's what I was actually after.

I did not say RVM can "mimic" Amstrad monitors, merely that it's at the moment the best solution for somebody who wants to quickly and easily get the "CRT look", which is not limited only to CTM/MM btw. Most people won't really know the difference between difefrent shadowmasks and such. Those who do can try to tweak one of the Retroarch shaders.

I mean, unless your shader, which does look interesting, is actually available somewhere. Is it?

[roudoudou]

I'm not sure you realize how "proving" something works
I did not say RVM can "mimic" Amstrad monitors, merely that it's at the moment the best solution for somebody who wants to quickly and easily get the "CRT look", which is not limited only to CTM/MM btw. Most people won't really know the difference between difefrent shadowmasks and such. Those who do can try to tweak one of the Retroarch shaders.

I mean, unless your shader, which does look interesting, is actually available somewhere. Is it?

Sure millenials won't know the difference between CRT, shadowmask, trinitron and CTM/MM but not me  (and i hope, not people who remember their CPC)

Now the code is only pure simple C code but i can already say that the code is scalable (multi-thread or shader later)

I'm talking with megachur (cpc-emu-power author) to see what can we do, but i can already explain what i'm doind and why

ps: About proof, i suggest you to read how "burden of proof"  works we are not talking about mathematics but software capabilities but anyway, you told yourself that RVM cannot mimic CTM 

[arkive]

you told yourself that RVM cannot mimic CTM 

Umm... no, mate, that's what you said that I said, but I have never said it I think we have a bit of a language barrier situation here.

Anyway, looking forward to your implementation. Until then, RVM is a good solution for a quick CRT fix, and for those who want more authenticity there is CRT-Royale and other shaders where you can tweak slot mask settings.

[Gryzor]

Here is a closeup of a CTM MM monitor

That moire is triggering my astigmatism

[gerald]

Sure millenials won't know the difference between CRT, shadowmask, trinitron and CTM/MM but not me  (and i hope, not people who remember their CPC)

They even think that
- a CRT have a slow luminosity scan affecting them (Beat due to frequency offset between the of a camera looking at a CRT and the CRT, but never affecting your eye)
- a CRT always display static when the CPC is off (static is only present when you are looking at the output of untuned tuner, which does not exists on a CTM)

[roudoudou]

still improving