Looking perfectly fine is a very subjective assessment. It is fine for most people, but you simply cannot assume that either technology will be better or worse. It depends on many factors. Assumptions usually bite you in the ass. You should know that by now, Arfa.
Leonard
You may not care, but I'm going to tell you anyway :)
It's from Biology, not physics; RGB are the peak sensitivities of the three colour receptors in the most common human retina. We're so poor at telling them apart that a red-green mix looks pretty much like some kind of yellow. (Narrow spectrum lamps are fine for TV, but they can make your wallpaper look a bit odd, which is one of the CFL problems)
Most common sort? Well, colour blindness is an obvious case. But apparently a few women have 4-colour vision.
And for true colour accuracy (though without speed or much resolution) look at the Mantis Shrimp. IIRC it has sensors for polarisation and a complete spectrometer build into its eye.
Andy
Andy Champ coughed up some electrons that declared:
Just out of interest, what's the 4th colour?
I'm getting that "Geordie" moment
Think that was more to do with the deficiencies of the then tube colour cameras. Three or four tubes - usually Plumblicons. Which would show Magenta as bright green, etc. And of course many CRT sets didn't use the best phosphors - more concerned with how bright they'd go.
Heh heh - advertising? I play with LEDs quite a bit, and they are getting better but still don't give as good a light quality as the best fluorescents.
Flesh tones contain a vast range of colour shades even on the one face - unless it's Des O'Connor's makeup. Wasn't talking about a quick glance.
Well yes and I agree. They're pushing them on TV too. But I haven't actually seen one. Perhaps they are as good as claimed. Cynical me doubts it.
More to the point to compare with HID in cars?
Thing is for domestic light my preference is halogen, quality wise. Expensive fluorescent tubes can match that well enough. CFLs not. Nor any LED I've yet tried.
Well no, I don't think it was. Take a look at
No, I wasn't either. I have two friends who both own top end digital SLRs, one because he is a professional photographer, and the other because he is a very keen hobbyist. I have looked at the viewfinder images closely on both of these cameras, and the rendition of flesh tones in all the varieties is excellent, and the professional of the two has commented to me how good he thinks the viewfinder is at colour rendition under all light levels (input that is, not viewing conditions).
Contrary to what you believe about the phosphors on CRTs, I don't believe that there has been any significant change in their colour rendition capabilities since the earliest delta gun tubes in the uk, which I worked with from about 1970. Even back then, if you put in the time to ensure that the decoder was correctly adjusted, and the CRT colour balance and tracking was correctly set, they had the ability to render flesh tones superbly. In fact this criterion was the main one we used to subjectively evaluate the performance of a set, and was one of the main reasons for the broadcasters using a little girl, whose skin was 'natural' and had no makeup, on test card F. In contrast (no pun intended !) I think that the colour rendition of most LCD TV sets - particularly in the case of flesh tones, is nothing less than dreadful. So if LED backlighting improves on this - and the case of the camera viewfinder images would tend to support this view - then that will be good.
Why particularly ? I was just trying to draw a comparison as to the relative efficiencies of a 'standard' 50 watt halogen headlamp bulb, which we all have a pretty fair idea of the brightness of, and the same thing in a LED version, which is likely to be at least as bright, if not brighter, otherwise there would be no point in the manufacturers trying to use them. If the LED equivalent power consumption was say 10 watts, then we would know that LED backlighting of LCDs was likely going to be more efficient than CCFL backlighting, which we already know consumes around 100 watts to light a 32" screen. If on the other hand the LED equivalent power was 50 or 75 watts, then we would know that it was going to be no better, and possibly worse.
Agreed all four points
Arfa
Oh, but there was. The original delta gun shadow mask tubes used the correct NTSC phosphors. Which gave a pretty pure red. The rot really came in with PIL tubes which used a very 'orange' red phosphor simply because it allowed a brighter picture. And that had real implications to flesh tones. Took many years before that was corrected.
Hmmm. I can't say that I remember slot mask / in line tubes producing any worse a picture, in terms of colour rendition, than deltas. Certainly, they were an improvement in convergence and extremity focus - perhaps even overall 'sharpness'. If the colour / output of the red phosphor did not match the transmitted weighting factor for that colour, I would have thought that this would have caused serious problems for rendering whites and greys correctly, and would have had a significantly pronounced effect on the ability of the tube to render subtleties such as flesh tones. An 'orangy' red would have screwed about with the chromaticity diagram, and completely altered the pallette of colours that the tube *could* produce from just three primaries. It would be like taking a printer's pantone colour chart, and redefining all the hues, wouldn't it ?
We had some pretty fussy customers back then with serious pots of money, and I can't recall any colour accuracy issues ever arising - aside from one particular customer who used to complain on a weekly basis that colours were "bleeding through" (convergence issues !) and in the summer that there was something wrong because the grass in front of the wicket on the cricket, was yellow ...
Nor can I recall any mention of this either in the trade press, or at our company's training school, which was recognised as being one of the best that there was.
Anyway, going back to chromaticity diagrams, did you look at the link to an explanation of 'non-spectral colours' to see what I was talking about, outside of any differences which there may or may not have been with the phosphor colours ?
Arfa
Top level digital SLRs don't use any electronics in the viewfinder, its all done with mirrors. There are only a few that use electronic viewfinders and they are low end.
I would almost bet my life that this is absolutely backwards -- it was the original phosphors that were orangish, improving only with the rare-earth phosphors of the early '60s. (I remember Sylvania's radio ads.)
In fact, I'm pretty certain that most of what's being posted about color TV and color analysis/reproduction is utter bilge. But I don't have a comprehensive understanding of this material (it's not easy), so I'm pretty much keeping my mouth shut.
I'm pretty sure that one of them told me that his camera was over a grand's worth, so I wouldn't call that particularly low end, although I am sure there are others more expensive. If they do not have an LCD panel on them to at least review the pictures you have taken, without having to plug the thing into a computer, that rather defeats the object of it being a portable 'digital' camera, doesn't it ? Even the 3 grand offering on this page has a
3" LCDArfa
Several DSLRs have live LCD viewing, which could be considered a viewfinder, as it serves the same function. I recently purchased such a camera (though not for that reason). I haven't checked skin tones, but the color rendition is not obviously "off".
Perhaps I'll drag out my Macbeth color checker and compare under noon daylight -- the next time we have any in Seattle.
One of the best uses for the LCD panel is to confirm the camera's color-temperature setting. It's particularly useful when fine-tuning the green-magenta axis under fluorescent light.
As I write this, I'm watching CNN on my cheap-but-good 32" Vizio. Most are perhaps slightly "warmer" than they should be. Not having the original flesh for comparison, I can't know for sure.
Colour TV didn't arrive in the UK 'till the late '60s. PIL tubes were some years after that.
Quite a bit of what I'm saying comes from working in TV production - although I'm on the sound side. But hear plenty from those who work on the vision side of things. ;-) And it was certainly the case that Grade 1 picture monitors continued with delta gun tubes long after PIL were introduced domestically - and stuck with the original NTSC phosphors. As this was the standard the cameras were 'calibrated' to.
And your posts use smoke and mirrors.
But there was no "original" NTSC red phosphor -- just a standard for it, that the original red phosphors didn't meet.
I /remember/ this from 45 years ago. (I read "Radio-Electronics" and "Electronics World".) The available red phosphor was not very efficient, and when driven hard, it turned "orangey" at high current levels.
As for any differences between professional and consumer CRTs... It's true that consumer CRTs were often designed for brightness * (rather than color accuracy or gamut). About 15 years ago, Mitsubishi brought out a consumer CRT with "filtered" phosphors that more-closely approached the NTSC standard
** -- at the expense of brightness. The sets using it quickly flopped, because (at least then) people were more interested in brightness than clarity.
Me, if I want to know that my screen is rendering colour correctly, I stick my Colorvision Spyder to it & measure it. That way, I know for sure.
LOL. It didn't occur to him that well trampled grass, in summer, is often yellow?
Correct. I have two DSLRs, (Canon EOS 10D, & EOS 1Dmk2), & they both use optical viewfinders. I certainly wouldn't waste my money on DSLRs with electronic viewfinders.
Are you kidding? My EOS 1Dmk2 cost $7000AUD. A grand is nothing for a decent DSLR.
Sure, but the LCD is to review the shot after you've taken it. You use the optical viewfinder when you're taking your shot.
Correct.
Well, on some newer models you have a feature called "Live View", where you can use the LCD to focus, etc, but no serious photographer would use that in preference to the traditional viewfinder. OTOH, the LCD is really handy to ensure that the shot turned out the way that you wanted it to.
You might be surprised. I had a client much younger than myself who was confused about the difference between a flat screen CRT vs an LCD screen.
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