Questions that do not deserve a thread

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eccoboy
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Re: Questions that do not deserve a thread

Post by eccoboy »

The white residue won't hurt anything. I usually have some on my boards every time. Trying cleaning it with alcohol. Some might clean off. And "no clean" flux is intended to not be cleaned. However, this is debatable. You can search online for both the clean or not to clean topic and white residue topic to find out more.
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

So, I ordered a Sega Saturn VGA cable from Retro Access earlier this year / got the cable roughly ~2 months ago... it was via the custom cable builder section of the site, and I specified in the notes that I did not want or need a 470ohm resistor in the cable. However, I was completely unaware that they also put 220uf capacitors in said cables (on the sync line in the VGA hood, before said line goes into VGA pin 13).

This Saturn cable will not work with my Extron RGB interface or my Apple IIgs monitor (I have a funky VGA -> DA-15 adapter that does work fine via a SCART to VGA with a LM1881, but I am phasing all my SCART stuff out of my setup). When it's connected to my GBS 8220 (w/ GBS Control & clockgen etc) the output image is *extremely* dim.

I am assuming this is probably because of the 220uf capacitor in there... right? I've also been wondering if perhaps there *is* a 470ohm resistor in there somewhere (IDK where they usually put 'em) and my request was overlooked. Beats me! Anyhoo it's a shame, don't currently have a way to properly remove that cap from the sync line...

For the sake of being thorough, it's a RG-JX2 V-Saturn aka 'Model 2' Saturn. I know the need (or lack thereof) for a 220uf cap for the Model 2s has been debated before, as far as I can remember.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

hello,

I would like to ask if I want to output 320x240p 60fps game using HDMI for a modern TV and a CRT\PVM. which resolutions should it be?

I know many tvs don't accept 320x240p but want it to be something like 720x240 @ 60 fps to be like standard 480i 13.5 MHz pixel clock... However, if this 720x240p60 signal is passed to analog transcoder which converts it to analog rgb or ypbpr then fed into a crt, what is going to happen?

will it be displayed?
will it be displayed in the correct 4:3 ratio?

thanks
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Unseen
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Re: Questions that do not deserve a thread

Post by Unseen »

VEGETA wrote:will it be displayed?
will it be displayed in the correct 4:3 ratio?
Consider this: How can the analog display tell if the signal has 320, 640 or 720 pixels per line? For simplicity, assume that you are looking at an all-black image.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

Unseen wrote:
VEGETA wrote:will it be displayed?
will it be displayed in the correct 4:3 ratio?
Consider this: How can the analog display tell if the signal has 320, 640 or 720 pixels per line? For simplicity, assume that you are looking at an all-black image.
so the solution is just using 480i equivalent of 320x240p60, which is about 640x480i30. or... maybe use 320x240p60 as active area while total lines are 858x525 which is the same for 480i material. what do you think?
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Extrems
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Re: Questions that do not deserve a thread

Post by Extrems »

I think Unseen's point completely flew over your head.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

Extrems wrote:I think Unseen's point completely flew over your head.
I do get what he said, really.

My point is that CRTs want 15 khz video signal, this could have 480i, 240p, 224p, 288p, etc... my suggestion was to deliver 15khz signal but ensure the active area is 320x240p. By using the same settings as true NTSC 480i stream but has only 240 progressive lines... I am not sure if it will work or not, therefore I am asking.

On the other hand, if I deliver 720x240p signal to a CRT, what would be displayed? assuming the actual picture is still 320x240 while the rest of image is black in the horizontal sides.

what about the 5x, what actual resolution does it deliver for 240p downscale? the GBS-C?
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Unseen
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Re: Questions that do not deserve a thread

Post by Unseen »

VEGETA wrote:so the solution is just using 480i equivalent of 320x240p60, which is about 640x480i30.
Why do you think that these two are equivalent?
maybe use 320x240p60 as active area while total lines are 858x525 which is the same for 480i material. what do you think?
Your original posting was not very clear (as usual), but I looked like the premise was to scale a 320x240 picture to 720x240. What you seem to propose here would be to take the original 320 horizontal pixels and window-box them within the 720 active pixels of your target signal? It would change the answers to at least one of your two original questions, but the guiding question I posted should still be applicable.

Maybe this will help: The sync signals tell an analog TV when it is time to return the electron beam to the top (VSync) or left (HSync) of the picture. But how does it know when to reach the right or bottom sides and which lines (vertical) or which part of the line (horizontal) it should show? As an additional hint, there are analog TV standards where blanking and black are indistinguishable from each other.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

Why do you think that these two are equivalent?
not 100% equivalent, but same horizontal frequency, same or near pixel clock.
Your original posting was not very clear (as usual), but I looked like the premise was to scale a 320x240 picture to 720x240. What you seem to propose here would be to take the original 320 horizontal pixels and window-box them within the 720 active pixels of your target signal? It would change the answers to at least one of your two original questions, but the guiding question I posted should still be applicable.

Maybe this will help: The sync signals tell an analog TV when it is time to return the electron beam to the top (VSync) or left (HSync) of the picture. But how does it know when to reach the right or bottom sides and which lines (vertical) or which part of the line (horizontal) it should show? As an additional hint, there are analog TV standards where blanking and black are indistinguishable from each other.
Ok then I will explain more straightforward. I want to achieve the ability to send 320x240 or similar very small pixel clock signals via HDMI. However, the system I am using in my design resulted in that 240p content pixel frequency is very low and cannot be sent, while 480i is doable. So there is a minimum frequency to have. therefore I thought about manipulating it this way to fit.

However, the manufacturer responded that I can do this by implementing "pixel repetition" which seems on all HDMI TX ICs. Then, the sink device would ignore the repeated pixels.
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Re: Questions that do not deserve a thread

Post by Unseen »

VEGETA wrote:However, the system I am using in my design resulted in that 240p content pixel frequency is very low and cannot be sent, while 480i is doable.
Indeed, DVI and thus HDMI requires a minimum pixel clock of 25MHz. If I remember correctly, I only ever saw one device that accepted a signal with less than that, but it is not something I tend to test very often.
However, the manufacturer responded that I can do this by implementing "pixel repetition" which seems on all HDMI TX ICs. Then, the sink device would ignore the repeated pixels.
Yes, that is how HDMI handles all CEA SD signals (e.h. 720x480i) which use an actual pixel clock of 13.5MHz. I believe it is not specified which of the repeated pixels the sink should use, but since they are supposed to be identical it does not matter in practice.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

do you know how GBS-C and 5X achieve downscaling to 240p? I mean at what active area resolution do they output?

can CRTs and analog monitors actually use the pixel repetition 240p output correctly?
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

kitty666cats wrote:So, I ordered a Sega Saturn VGA cable from Retro Access earlier this year / got the cable roughly ~2 months ago... it was via the custom cable builder section of the site, and I specified in the notes that I did not want or need a 470ohm resistor in the cable. However, I was completely unaware that they also put 220uf capacitors in said cables (on the sync line in the VGA hood, before said line goes into VGA pin 13).

This Saturn cable will not work with my Extron RGB interface or my Apple IIgs monitor (I have a funky VGA -> DA-15 adapter that does work fine via a SCART to VGA with a LM1881, but I am phasing all my SCART stuff out of my setup). When it's connected to my GBS 8220 (w/ GBS Control & clockgen etc) the output image is *extremely* dim.

I am assuming this is probably because of the 220uf capacitor in there... right? I've also been wondering if perhaps there *is* a 470ohm resistor in there somewhere (IDK where they usually put 'em) and my request was overlooked. Beats me! Anyhoo it's a shame, don't currently have a way to properly remove that cap from the sync line...

For the sake of being thorough, it's a RG-JX2 V-Saturn aka 'Model 2' Saturn. I know the need (or lack thereof) for a 220uf cap for the Model 2s has been debated before, as far as I can remember.
...anyone? I have asked about this several places with no input, lol. I emailed R.A. but I doubt I will hear back
SamIAm MkII
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Re: Questions that do not deserve a thread

Post by SamIAm MkII »

kitty666cats wrote:...anyone? I have asked about this several places with no input, lol. I emailed R.A. but I doubt I will hear back
It's hard to say for certain what's going on, especially with the dim-picture result you're getting. However, the AC coupling capacitor on the sync line is going to have the effect of making most of the sync pulse itself a negative voltage, and I suspect that's what's tripping up some of your devices. If you can somehow finagle a diode between ground and the C-sync line after the capacitor, you can change this.

Click the switch on and off in this simulator and look at what happens to the signal. The diode provides DC restoration, and I'm pretty sure that this is exactly what devices like the LM1881 have built into them.

I built my own Saturn cable, and what I remember about the Saturn's C-sync is that it's simply 5Vp-p (or something near that) which, if connected directly to an input that terminates in 75 ohms, results in a concerning level of current being drawn. This is where an in-series resistor, which both divides the voltage and limits current, would come in. However, many devices don't terminate sync with 75 ohms but rather something like 510, so it's not strictly necessary.

Throwing AC coupling capacitors on sync lines seems like a bad idea in general to me. Maybe some systems have a big DC bias in their C-sync signals, but if the thing receiving the sync isn't set up to do a DC restore, it won't work. Not with a negative-going sync pulse.
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

SamIAm MkII wrote:
kitty666cats wrote:...anyone? I have asked about this several places with no input, lol. I emailed R.A. but I doubt I will hear back
It's hard to say for certain what's going on, especially with the dim-picture result you're getting. However, the AC coupling capacitor on the sync line is going to have the effect of making most of the sync pulse itself a negative voltage, and I suspect that's what's tripping up some of your devices. If you can somehow finagle a diode between ground and the C-sync line after the capacitor, you can change this.

Click the switch on and off in this simulator and look at what happens to the signal. The diode provides DC restoration, and I'm pretty sure that this is exactly what devices like the LM1881 have built into them.

I built my own Saturn cable, and what I remember about the Saturn's C-sync is that it's simply 5Vp-p (or something near that) which, if connected directly to an input that terminates in 75 ohms, results in a concerning level of current being drawn. This is where an in-series resistor, which both divides the voltage and limits current, would come in. However, many devices don't terminate sync with 75 ohms but rather something like 510, so it's not strictly necessary.

Throwing AC coupling capacitors on sync lines seems like a bad idea in general to me. Maybe some systems have a big DC bias in their C-sync signals, but if the thing receiving the sync isn't set up to do a DC restore, it won't work. Not with a negative-going sync pulse.
Hmm, of note - the cable works fine on my presentation monitor... and everything on said monitor's 15kHz RGB input is fed through one of these X-Vue Gamma Boosts (adjusting when I see fit, the device really shines most chained after a HDMI to VGA on 31+kHz though. But I also own an X-Vue Box1020 which definitely has a better Gamma adjustment circuit):

http://www.curtpalme.com/GammaX.shtm


...it has a switch on it for forced negative sync (and if sync is already negative, it's passed through). This got me thinking 'what if I try chaining the Gamma Boost *before* the Extron interface/GBSControl'. I'd be a little bit hesitant using the thing on the input of a GBS board (seems like a much better idea putting it on the output end), but not so much with an Extron interface. The unit I have specifically is a Extron RGB 164xi. It's one of the units that you have to open up/adjust jumpers if you want serration pulse removal or forced negative sync.

I guess I have a lot of things I could try w/ the Extron, heh. But it really woulda been nice not having to deal with any of this at all... *really* wish they made it clear that the Saturn cable would have that capacitor, their only disclaimer (as far as I remember) is that every custom RGB cable will have a 470ohm resistor in it unless you ask.

u_u;
SavagePencil
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Re: Questions that do not deserve a thread

Post by SavagePencil »

Question that doesn't deserve a thread because one probably exists and I'm hoping to be pointed there.

Looking for a TV or monitor recommendation that fits these specs:
* Somewhere in the 24-36" range
* Can be tated
* Plays nice with OSSC
* 16:9
* Low latency
Guile
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Re: Questions that do not deserve a thread

Post by Guile »

Does anyone have a recommendation for a desoldering gun or other device? I've tried those flimsy pumps and wick and I don't get good results. Unfortunately I have lifted some solder pads from too much heat.
ldeveraux
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Re: Questions that do not deserve a thread

Post by ldeveraux »

Guile wrote:Does anyone have a recommendation for a desoldering gun or other device? I've tried those flimsy pumps and wick and I don't get good results. Unfortunately I have lifted some solder pads from too much heat.
I've you've got the means, the Hakko is the best around. Very pricey but pays for itself in speed and reliability.
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Re: Questions that do not deserve a thread

Post by Guile »

ldeveraux wrote:I've you've got the means, the Hakko is the best around. Very pricey but pays for itself in speed and reliability.
Do you need to do anything with the power source on that? I saw some people say the voltage is different because it's set for Japanese power sources.
ldeveraux
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Re: Questions that do not deserve a thread

Post by ldeveraux »

Guile wrote:
ldeveraux wrote:I've you've got the means, the Hakko is the best around. Very pricey but pays for itself in speed and reliability.
Do you need to do anything with the power source on that? I saw some people say the voltage is different because it's set for Japanese power sources.
I bought it off Amazon. You plug it in and use it.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

hello

is there any real application or demand for 1080p analog video? like component or RGB.. in this retro gaming scene. cuz most stuff like CRTs and so on are capped at 1080i
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

VEGETA wrote:hello

is there any real application or demand for 1080p analog video? like component or RGB.. in this retro gaming scene. cuz most stuff like CRTs and so on are capped at 1080i
Projectors, for one.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

kitty666cats wrote:
VEGETA wrote:hello

is there any real application or demand for 1080p analog video? like component or RGB.. in this retro gaming scene. cuz most stuff like CRTs and so on are capped at 1080i
Projectors, for one.
so people play on projectors these days?

All I know is that HD CRTs are about 1080i, some PC CRTs can go to 1920x1440 or so but I am not sure.
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kitty666cats
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Re: Questions that do not deserve a thread

Post by kitty666cats »

VEGETA wrote:
kitty666cats wrote:
VEGETA wrote:hello

is there any real application or demand for 1080p analog video? like component or RGB.. in this retro gaming scene. cuz most stuff like CRTs and so on are capped at 1080i
Projectors, for one.
so people play on projectors these days?

All I know is that HD CRTs are about 1080i, some PC CRTs can go to 1920x1440 or so but I am not sure.
No, that was just one example. CRT projectors aren't some big thing right now, they are just a good example of very high resolution compatible analog equipment. Almost *any* PC CRT that is 19" or more from ~mid 90s and beyond can display 1080p. There are also tons of TVs that support 1080p via component and VGA but may not necessarily have HDMI inputs (many Plasmas for example)
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

Hello,

anyone tried or want 4k60 scalers? right now only Extron stuff exist such as this one: https://www.extron.com/product/dschdhd4k and the rest.

is 4k60 scalers worth such a price? I mean 1k$ or even at 800$.
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Fudoh
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Re: Questions that do not deserve a thread

Post by Fudoh »

I have the DSC HD-HD 4K Plus A. Really nice machine, but I doubt that any gamers would have some real use for it. It performs really good, but so do the majority of TVs. Very hard to justify the price.

It does save a lot of time when you do 1080p/1200p/1440p captures and want to upscale to 4K into a live 4K streaming or re-capture setup though.

The DSC 401 is rather new and I haven't tried that one yet. The HD-HD (basically the predecessor to the 401) was heavily scaled down in terms of features (e.g. in terms of free aspect ratio control). Don't know yet, if the 401 is following the 301 here or the HD-HD instead.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

I bet you have retro scalers like OSSC and 5x, so what is the need for that expensive extron device which these scalers can't deliver?

how much both of these cost? I'd really like to see a good teardown of them to see what is inside.

it doesn't seem to have an official price shown. However, for approx. of 1500$ (ebay has a used one for 1700$) I don't think anyone would buy them especially that you would need another scaler with.

But what if they are priced at 700-800$ with analog video inputs? will this be a good price? I mean people buying framemeister for 1200$ now.

I saw DSC-301 on ebay for > 80$ or so, seems good but only up to 1080p or so.

I keep reading about modern TVs don't scale 720p\1080p very good, especially retro stuff with pixels... I don't know if it is in terms of input lag or just not so sharp. I don't have the knowledge nor the capabilities to test such claims and they are also contradicted by other people who say the exact opposite hhh.
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Fudoh
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Re: Questions that do not deserve a thread

Post by Fudoh »

so what is the need for that expensive extron device which these scalers can't deliver?
as said, it's hard to justify those. Especially considering that current consumer OLEDs don't have true 444 RGB panels. In general a 4K scaler allows you to completely eliminate the display's processing. You basically move everything you want to control (like aspect ratio, over/underscan control) to an external device, which potentially does a better job than your TV (or monitor).
how much both of these cost? I'd really like to see a good teardown of them to see what is inside.
The DSC 401 is too new to be found used on ebay. The 401 is $1200 EUR (all prices without vat), the 401A is $1700 EUR. The HD-HD 4K Plus A is $2500 and the xi is $4600. So the sub-$1000 price tag for the 4K Plus A on ebay isn't too bad (if you can make any use of them).
But what if they are priced at 700-800$ with analog video inputs? will this be a good price? I mean people buying framemeister for 1200$ now.
you don't get any of the gaming features out of those. They won't properly handle 15khz (the 301 has TERRIBLE deinterlacing). External 4:4:4 processing and upscaling is still hard to find. The 5X does an excellent job now, but it still falling short when compared to a true 4:4:4 processing path. The OSSC is full 4:4:4, but it's limited to its line-multiplying output resolutions (so no 1080p from a 480p signal). And almost all home theater processors are 4:2:2 only anyway.
I keep reading about modern TVs don't scale 720p\1080p very good, especially retro stuff with pixels... I don't know if it is in terms of input lag or just not so sharp. I don't have the knowledge nor the capabilities to test such claims
yeah? I guess you have eyes, so you can judge by yourself. But in general: even if TVs aren't perfect when uspcaling 720p or 1080p to 4K, it's still just a subtle difference. Coming from a low-res 240p signal I would say 90% of the quality comes from the initial processing and upscaling to 720p and just a mere 10% result from the secondary scaling to the display's native resolution.
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VEGETA
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Re: Questions that do not deserve a thread

Post by VEGETA »

current consumer OLEDs don't have true 444 RGB panels
first time I know this, but why? oleds should be the future technology. 4k oled tvs are +1000$ at least and yet no 444 processing?
all prices without vat
huge prices! for sure retro gamers won't be getting them, I wonder who wants to!
you don't get any of the gaming features out of those. They won't properly handle 15khz (the 301 has TERRIBLE deinterlacing).
my question was to assume they have proper analog video inputs and 15~31khz support like current scalers and tailored to retro gaming.. what price range is good enough? 700-800$? are people in your opinion ready to pay this price range?

actually, retro scalers are slowly increasing in their pricing as newer projects will cost more and more. can't complain when you want more power and features.
The 5X does an excellent job now, but it still falling short when compared to a true 4:4:4 processing path.
People don't seem to be bothered when comparing this to its features I guess.
The OSSC is full 4:4:4, but it's limited to its line-multiplying output resolutions
yes, but the pro will support custom resolutions. my biggest complain of ossc classic is the bob deinterlacing only option especially for 480i games but still a bargain for the price.
yeah? I guess you have eyes, so you can judge by yourself.
I don't own such TVs yet and not really that interested. I wrote this to say how amazed I am to see people say the exact opposite opinion on the same issue while both tested and verified their results... don't you see it interesting?
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Re: Questions that do not deserve a thread

Post by Guspaz »

Fudoh wrote:as said, it's hard to justify those. Especially considering that current consumer OLEDs don't have true 444 RGB panels.
This is nonsense. I just verified this on my LG C1 OLED by sending RTINGs' chroma subsampling test pattern (https://www.rtings.com/images/test-mate ... ma-444.png). I sent a 4K120 444 RGB 10bpp signal to it and there is no chroma subsampling happening. All the parts of the test pattern show full resolution.

Remember that while OLED TVs have an RGBW subpixel pattern, they have four subpixels per pixel. There is no pentile or other subpixel sharing going on.
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Re: Questions that do not deserve a thread

Post by strayan »

Guspaz wrote:OLED TVs have an RGBW subpixel pattern, they have four subpixels per pixel. There is no pentile or other subpixel sharing going on.
I thought they had a BGRW subpixel pattern.
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