Old display chatter mode = 1
On Sunday, October 4, 2020 at 3:01:30 PM UTC-7, Michael J. Mahon wrote:
> Luminance bandwidth of consumer TVs was limited to about 3MHz by the chroma
> subcarrier filter. This was actually seen as desirable, since it made solid
> color areas look uniform rather than “dotted”.
>
Indeed!
Later models, beginning in the later 80's began to open wide up. Broadcasts pushed it all too. I remember seeing TV graphics jump a resolution, from something roughly 320 to roughly 640, with the TV's able to employ better filters, "comb filter" comes to mind, to produce sharper images. An old indie station here stayed with simpler graphics well into the 90's and it was notable. I would look for the sets that showed the dot pattern, being just well executed, sharp circuits and CRT's, sans the filtering and such, and use them for games / computer use. Some people don't mind and seem to process the dots away.
Late 80's and most 90's era TV circuits ended up better than the CRT they were driving too. During that time period, one could get a smaller pitch masked CRT and upgrade a TV and notice! My personal set was a Zenith, hybrid. My fave TV ever! Had a vacuum tube H / V drive, transistor and IC circuits elsewhere. It was a 27" model, and I completely redid it with a 17" CRT that had basically a 2X finer pitch. When I got done, it was a full frame display, PVM "underscan" style. What I liked most about it was a pretty low noise color circuit, and it would widen right up. Performance was close to many of the better pictures in this thread, and rock solid stable.
The smaller CRT, and setup full frame made converging it near spot on. Took a long time, but it was worth it at the time. Being able to read 80 columns and get a great color display was expensive for this rural kid. Doing CRT setups and alignment was fun at the time. Like a puzzle. The more you put in, the better it looks. Then it all fades after a couple years, and do it again... I don't miss the do it again part.
The other thing I noticed was increasingly better art direction as we moved to DVD media and really began to get signals into the home that were better than the TV's and or many broadcasts. Luma changes at higher resolution, color changes at somewhat lower pushed NTSC right to the edge. Anyone connecting a DVD to S-video or component / RGB got the big jump, and watching movies on a CRT was kind of golden for a time. That "dotted" look got filtered and processed away some. Would be super interesting to compare some sets and broadcasts from 70's, 80's and 90's. The improvements were pretty dramatic! That's the "retro" look many are seeking today. It's distinctive.
> The Apple Color Composite monitor bypassed the chroma filter when in
> monochrome mode, so that 80-column text would be readable.
Cool. On my "custom" Zenith, I set the color killer trigger right to the edge, and it basically did the same thing. Doing that meant marginal broadcasts ended up black and white. At the time, I didn't care much. The computer was where it's at! Many TV's included that particular adjustment, and it was set to permit color more than not to avoid "but it's not in color" calls on marginal signals. One difference is I basically widened the set up. That "dot" or "line" look actually appeals and in my view, is a big part of what makes great Apple graphics art great! The photo Tempest put here of the PoP title screen is an exemplary example.
On that note, older B&W broadcasts were sharper than we often see them today. That 3.58Mhz knocked what was roughly 500'ish lines down to roughly 300'ish lines. Old programs broadcast in mono looked crazy sharp on a set designed for them. I got to experience this a few times as a younger kid and it always stuck with me. Grandparents had an absolutely huge monochrome TV. It was fun to watch. Honestly, that thing would have done the 80 column text no problem. Hard to find those now. If I did find one, I would totally convert it for gaming! Great phosphors, will leave trails.
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