View Full Version : A subjective NTSC vs. ATSC observation...


Pete Deksnis
06-08-2014, 01:10 PM
Previously penned by 'Old TV Nut' elsewhere on Videocarma:

"The HDTV system, which is designed for the modern phosphors and has the colors properly matrixed back at the camera where the signals are linear, can produce reds the equivalent of the early NTSC, but cannot do the Kelly greens and deep cyans of NTSC because the green is more yellow."

Ah... finally a reason why the neckwear around Claude Rains' Prince-John character in the 1938 Technicolor "Robin Hood" is so vivid and striking a cyan on my CT-100, but on RCA's last set (the 1999, near-HD, 16X9, 38-inch, CRT-based model f38310) it's just -- well -- part of the costume.

A second striking sight is the vivid red smock worn by Basil Rathbone's Sir Guy character. Yes, you can say it stands out on the f38310. Yes, maybe I've lavishly and excessivly boosted the CTC2 color control. But there seems to be another factor in the 15GP22-presented red smock versus that on the f38310...

Perhaps it's a narrower spectral characteristic of the 15G red? :scratch2:

Pete

Penthode
06-09-2014, 08:57 PM
I know a photograph would probably not do it justice. But is it possible to illustrate this with a few pics?

etype2
06-10-2014, 08:53 AM
Do you have your modern sets calibrated to ISF standards?

An interesting article: https://www.imagingscience.com/upload/Language%20of%20Light%20082709.pdf

https://www.imagingscience.com/upload/Colorimetry%20for%20CMS%202008.pdf

old_tv_nut
06-10-2014, 09:15 AM
They missed slightly on the definition of Illuminant C. It DOES have the stated correlated color temperature. However, it is not "daylight minus the UV region," but a physical approximation of daylight minus the UV region, obtained by light from an incandescent lamp of known color temperature passing through a blue chemical solution of known composition, concentration and thickness. It comes from a time when it was worthwhile to set up such a physical source rather than do the succesive multiplications wavelength by wavelength from a defined, measured daylight spectrum. The availability of computers has obsoleted the old procedure.

Pete Deksnis
06-10-2014, 04:37 PM
I know a photograph would probably not do it justice. But is it possible to illustrate this with a few pics?

Would try but my CT-100 is down:tears:; H-V crapped out a while ago. But the description above was observed a number of times during the past year. Particularly the cyan, and so when I ran across Wayne's earlier post, two and two went together, although as I said, it's all subjective.


Also, when the King finally shows up in kingly garb, there is yet another striking red; it seems, subjectively of course, even more red than Sir Guy's.

I sure would like to have seen those costumes in person...

Pete

Pete Deksnis
06-10-2014, 04:41 PM
Do you have your modern sets calibrated to ISF standards? No, the set's still calibrated to whatever RCA did in Mexico back in 2002... :D

Pete

etype2
06-10-2014, 06:14 PM
Pete,

I owned that RCA set. Most televisions out the box are poorly calibrated including that RCA model. Back then and to a great extent today, sets are adjusted to give over saturated colors and contrast. (pop in the stores get more attention) The grey scale is way off (crushed black's) and the color temperature is way to high (blue) which makes the image look brighter but throws off the color accuracy. The sets user controls cannot fix the errors.

With professional calibration, the technician sets up a camera directly in front of the screen. It is incredibly sensitive. The room lighting in the environment around the set is evaluated. Together with proprietary software, the set will be adjusted as close as possible (to the limits of the given set) to a known standard set by the professional broadcast industry. The grey scale will be adjusted as close as possible to the D65 standard. (more shadow detail in dark scenes) The tracking will be adjusted for 16 brightness levels and for the primary colors, so that the colors will be as linear from top to bottom. Overscan will be eliminated. The set will be adjusted to display its best resolution. The color, tint, sharpness (no ringing) and white levels will be adjusted to the known standard.

After a set is professionally calibrated, most users report a dimmer, laid back image, but over time, they begin to appreciate the differences. They are no longer viewing retina burning images. They see more detail in dark scenes as well as in the skin tones and the entire color spectrum. Everything looks more balanced and natural.

Today's televisions and this particular RCA set have service menus which can be accessed by professionals like many of the VK members here. (I am not a professional). With the proper equipment, a much improved image can be obtained, but it will always be subjective, that's where calibrating to a known standard with proprietary software will remove some of the subjectivity.

I had my RCA F38310 professionally calibrated by an ISF technician and all subsequent sets including my flat panels. Once my eyes were "educated" to what a properly calibrated image looks like, I can never go back to an un-calibrated set. I was seeing movies the way the movie producer intended me to see them.

This is why I asked you the question and how it relates to your comment about color and subjectivity.

Eric H
06-10-2014, 07:45 PM
I saw a colorimetry chart somewhere on the Web and it showed the Plasma phosphors being nearly identical to a CRT, it had a little more range in each direction but not a whole lot.

My previous HD set was a Sony rear LCD projector, it made pictures in exactly the same way as the old three strip technicolor, one chip for each color, that set probably had the most vivid and accurate looking color of any set I've seen, it even did shades of yellow superbly, unfortunately the black levels were atrocious.

I found my BD copy of Robin Hood tonight and made some screen shots, however as usual the digital camera images come out much brighter than the actual image on the set and there are some vertical line artifacts, still they give some idea of the color spectrum.

Set is a three month old Panasonic Plasma, calibrated only by my eyeballs.

etype2
06-10-2014, 10:38 PM
Magnificent screenshots Eric.

A couple of screen shots from my Sharp 70 inch LCD post calibration:

http://www.visions4.net/journal/wp-content/uploads/Sharp-lc70le735u-SS-CBS-Nora-1920-WP.jpg

http://www.visions4.net/journal/wp-content/uploads/Sharp-735U-SS-19-1280-WP.jpg

Pete Deksnis
06-11-2014, 02:42 PM
Pete,

I owned that RCA set. Most televisions out the box are poorly calibrated including that RCA model. Back then and to a great extent today, sets are adjusted to give over saturated colors and contrast. (pop in the stores get more attention) The grey scale is way off (crushed black's) and the color temperature is way to high (blue) which makes the image look brighter but throws off the color accuracy. The sets user controls cannot fix the errors.

With professional calibration, the technician sets up a camera directly in front of the screen. It is incredibly sensitive. The room lighting in the environment around the set is evaluated. Together with proprietary software, the set will be adjusted as close as possible (to the limits of the given set) to a known standard set by the professional broadcast industry. The grey scale will be adjusted as close as possible to the D65 standard. (more shadow detail in dark scenes) The tracking will be adjusted for 16 brightness levels and for the primary colors, so that the colors will be as linear from top to bottom. Overscan will be eliminated. The set will be adjusted to display its best resolution. The color, tint, sharpness (no ringing) and white levels will be adjusted to the known standard.

After a set is professionally calibrated, most users report a dimmer, laid back image, but over time, they begin to appreciate the differences. They are no longer viewing retina burning images. They see more detail in dark scenes as well as in the skin tones and the entire color spectrum. Everything looks more balanced and natural.

Today's televisions and this particular RCA set have service menus which can be accessed by professionals like many of the VK members here. (I am not a professional). With the proper equipment, a much improved image can be obtained, but it will always be subjective, that's where calibrating to a known standard with proprietary software will remove some of the subjectivity.

I had my RCA F38310 professionally calibrated by an ISF technician and all subsequent sets including my flat panels. Once my eyes were "educated" to what a properly calibrated image looks like, I can never go back to an un-calibrated set. I was seeing movies the way the movie producer intended me to see them.

This is why I asked you the question and how it relates to your comment about color and subjectivity.
Thanks for your ISF-type pro setup summary. As mentioned, I did not attempt a similar calibration of the f38310; although, I did tweak the user controls, which includes resetting a wide-open contrast control as received from the factory.

However, I do try to set up a CT-100 based upon its design specifications as defined by the 1953NTSC standard. Back in the 2007 ETF convention an attempt was made to reproduce exactly what a viewer of a 15GP22 would experience watching a 1950s NTSC color broadcast.

At the end of the convention, the 15GP22-based set (a CT-100) was subjected to a series of tests.

Here is a link to a page from 2007 documenting the effort; the pertinant section is located at the bottom and begins with 'After the Accomplishment.'

For example, a modern colorimeter determined luminance and CIE x, y coordinate points to accurately measure gray-scale performance, which tracked well throughout its approximately 20- to 80-percent operating range.

http://www.earlytelevision.org/Deksnis/Dsite.htm

Pete

etype2
06-11-2014, 05:02 PM
Very interesting project. I went to your site, very enjoyable, nice to meet you. :-)

ChrisW6ATV
06-12-2014, 01:26 AM
It is amazing that that movie (Robin Hood) is from 1938. I need to pull out my HD DVD of it and watch it.

ceebee23
06-13-2014, 06:49 AM
Three strip technicolor remains at its best almost unbeatable for depth of colour ..like Kodachrome ...