Hi everyone,
I have nice CRT VGA monitor, but the picture is rather dark (and monitor is maxed out in contrast setting) so I would like to change (boost) contrast / gamma of Chameleon's VGA picture.
Is it even possible?
If yes - how to do it?
If not - do You know any hardware VGA gamma / contrast boost device?
Back then it was available (it was called GammaX: Gamma Boost), but now it is long out of stock...
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Don't Panic. Please wash hands.
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If you want a brighter picture on a monitor I would expect you actually need to lower the "contrast" setting and increase the "brightness" setting on your monitor instead.
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No,
I don't need brighter picture, I jusrt need more contrast / gamma.
If I increase brightness on my monitor, the pictures gets washed out and blacks are becoming grey. -
maybe the old crt is worn out from alot of use. The result is often that it will be more dim
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That said, its often possible to fix this.... by a qualified person obviously
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Note that this customer got a custom modification on his Chameleon that already boosts sharpness and brightness. So the "CRT is worn out" theory is even more likely.
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Indeed, I have mod that boosts sharpness, but not the brightness (at least not to my eye) - let alone contrast / gamma.
My CRT monitor is NOS, unused, no need to repair it.
From my old PC computer I got vivid and high contrast picture. -
but not the brightness (at least not to my eye)
Brightness is proportional to voltage on the RGB signals, and that has also changed - though only a small bit. What you're asking for is essentially a different colour palette. We've had a few discussions like this before in this forum, and it's essentially a problem of space - both in the FPGA, but also in the menu system, as making the palette configurable requires much more space than keeping it hardcoded to the "Pepto palette", which indeed feels a bit soft if compared to the (totally wrong) emulator palettes that are sometines being used.
Before we continue to discuss the palette, please launch an Amiga core and see if you are satisfied with that picture - if so, we're indeed talking about a palette change. If not, we may be talking about a cable problem, maybe even an impedance mismatch problem.
Jens
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Jens,
the Pepto palette is absolutely perfect and I really don't want to change it.
The only thing I would like to bring off is to add more contrast / gamma to the picture.
If not thru the Chameleon, I think some device could solve this issue (like old GammaX: Gamma Boost), but I can not find it enywhere...
I've checked NES and MegaDrive cores and the problem remained, so this is generally question of boosting up contrast / gamma directly from Chameleon's VGA output. -
the Pepto palette is absolutely perfect and I really don't want to change it.
The only thing I would like to bring off is to add more contrast / gamma to the picture.
You are contradicting yourself. Changing contrast/gamma is done by changing the palette.
I've checked NES and MegaDrive cores and the problem remained, so this is generally question of boosting up contrast / gamma directly from Chameleon's VGA output.
Feel free to measure voltages; they are perfectly in the 0-0.7V range when loaded with 75 Ohms. I really can't do anything else than recommending a different monitor here, as everything else you're requesting would be violating the standard.
Jens
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You are contradicting yourself. Changing contrast/gamma is done by changing the palette.
I really can't see any contradiction here.
All my life I change contrast / gamma settings on my TVs, monitors, PCs, other devives etc. and it has nothing to do with changing colors.
Color settings are for color settings, contrast settings are for contrast settings and gamma settings are for gamma settings.
One setting doesn't change another, they are separate and independent.
Feel free to measure voltages; they are perfectly in the 0-0.7V range when loaded with 75 Ohms. I really can't do anything else than recommending a different monitor here, as everything else you're requesting would be violating the standard.
I don't claim, that Chameleon's voltages aren't perfect.
And as i wrote before:
My CRT monitor is NOS, unused, no need to repair it or change for different monitor.
Why?
Because from other source (for instance my old PC computer) I got vivid and high contrast picture. -
If incresing contrast or gamma value = changing colors of Chameleon's C64 palette, that's too bad.
And in this case I just need some external contrast / gamma controller (device). -
All my life I change contrast / gamma settings on my TVs, monitors, PCs, other devives etc.
These controls are usually disabled when using the RGB input - best example is the 1084 monitor, widely used on C64 and Amiga computers.
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These controls are usually disabled when using the RGB input - best example is the 1084 monitor, widely used on C64 and Amiga computers.
Of course, but - for instance - all VGA monitors have those controls.
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If anyone is still interested in increasing VGA CRT display settings, I can recommend ALTONA AT-VGA300CV scaler.
Fantastic device, You can adjust settings like:
- contrast
- brightness
- RGB colors
- size
- sharpness
and many more
This device is long out of production, but if You manage to buy it I can guarantee, that You will be amazed how good can be picture from Chameleon on CRT monitor. -
- Marks thread as resolved after post creation.
