[QUOTE=etype2;3224992]
Quote:
Originally Posted by old_tv_nut
So you saw NTSC green and presumably other NTSC colors on the Sylvania CRT. And no professional camera could capture NTSC colors and now I mean still camera's? Is it possible for you to reproduce as close as possible a 1953 NTSC green color sample based on your knowledge?
I know what your going to say, how can I see it on my monitor. I have DCI-P3 which has 26% wider gamut over sRGB. Not as wide as 1953 NTSC though.
Edit: You said “If you put color bars on your old set, take a picture with a digital camera set to Adobe RGB or prophoto RGB, and display it on a wide-gamut monitor (or the old TV), then you should see the NTSC primaries and secondaries reproduced, sort of.” Would that be reduced luminance/saturation?
|
1) Current digital cameras can represent NTSC green in the raw file, or in a jpg file when the camera is set to AdobeRGB color space. Warning: really, you should only use raw files for this, as a jpg file with AdobeRGB is VERY likely to be misinterpreted as sRGB by practially all software out there. Although the camera can REPRESENT NTSC green, whether it will do so exactly if you take a picture of your NTSC CRT is iffy, for several reasons:
1) the spectral responses of the sensor are not linear combinations of the eye cone responses, so saturated colors are distorted to some extent. The good news is that the distortion tends to saturate very saturated colors more than reality, and move them towards the primaries. So, there is a good possibility the green bar will be recorded as fully saturated NTSC green.. Secondary colors (yellow, cyan, magenta) are more likely to give hue shifts.
2) Photographic cameras are not linear photometric/colorimetric devices. The programs that process raw files do not do linear photometric/colorimetric transforms of the raw data. They are trying to make a pretty picture of reality, so you when you take a picture off your NTSC tube, you end up with a picture of a picture, rather than a strict duplicate of what was on the screen.
3) If you have a monitor that reaches NTSC green, and it is properly profiled, Adobe products should do a decent job of showing the result of the camera response and the photographic processing. This should show the more saturated, less yellow green, but whether it will do so precisely is harder to say. For example, in Lightroom, you can choose multiple "camera profiles." None of these are labeled as colorimetric. From the sound of the titles, the closest might be Adobe Neutral, of for a Canon camera, Camera Matching "Faithful." But even these two are different from each other. Each of these profiles affects the hue, saturation, and luminance of the primary and secondary colors differently, not to mention image contrast, highlight and shadow compression, and on and on.
In the end, you have to ask yourself why go to all this effort. You can do it for your own gratification of viewing something on your wide-gamut monitor. You could perhaps share an image (in some format other than jpg) with someone else who has color-managed software and a calibrated and profiled wide-gamut monitor. But if your goal is to show pictures on the web to other TV restorers, the majority won't have all that, so the most reliable thing is still jpg and sRGB. If the viewer only has an sRGB monitor, that's the end of it.
So, yes, you can definitely go in the right direction to take a picture of, and then display, greens closer to NTSC (if your monitor has the capability), but you shouldn't expect precision.