1. Video experts: is there a difference between “green screen technology” and “blue screen technology” other than the choice of color channel you use as transparent? Or is it a different sort of arrangement in some way?
    And which is the one used by TV weather reporters?

  2. I’m not a video expert, but from what I’ve seen on the Web, it’s obvious that weather reporters use green.

  3. They are both the same technology. One advantage green has is that it has less clash with clothing, as green is less popular than blue.

  4. These are some good ones! I especially like the guy sitting on the horizon line. And yes, Brian is right. The blue or green is filtered out of the signal that gets overlaid onto the background scene. What amazes me is how the football TV folks inject the yellow “first-down” line over the ground but under the people.

  5. And green clothing is not popular because early color TVs made people wearing green look like zombies.

  6. I forgot to say, these are a good laugh-folio!

    Thanks for the answer on video technology. I also think the overlay lines on the football field are nice to have, and a bit puzzling for how its done. But probably the over-general category to put it in would be “augmented reality”. That used to be a somewhat specialized term, but now everybody has experienced at least Pokemon Go.

    The Andertoons also made me ask, is this channel 6 or really 9?

    I don’t know when or why I turned against Karina Longworth. “You Must Remember This” used to be among my top two or three podcasts. But I tried and failed to get into this new project she has with (spouse) Rian Johnson and Nate DiMeo, where they discuss a movie some or all of them had not previously seen. The first one, perhaps, (it’s the first one in my feed anyway) was about “Cast Away” and I realize I shouldn’t say anything about whether the movie resembles desert-island comic panels, as I haven’t seen the movie.

  7. “And green clothing is not popular because early color TVs made people wearing green look like zombies.”

    I can sort of see why that might mean green clothing is not popular with people old enough to remember early color TVs, but I’d think that’s a smallish subset of clothing-buyers these days. (And even such geezer-qualifier folks such as myself might have noticed things changed later, so I’m not sure if the explanation still works today.)

  8. Which cartoonist drew the desert island one? I need to send it to people (really!) but I’d want to send the original URL, if I can.

  9. “Tom the Dancing Bug” is one of my favorite comics, and I like when Bolling does Super-Fun-Pak in “Tom the Dancing Bug,” which will have six or seven fake comics all combined together in a fake comic page. However, I don’t generally think it works well in the GoComics form where they’re broken up into individual comics. If anyone want to check it out, I’d highly recommend looking at the full form, not the broken up form.

  10. I agree (with some exceptions), and would mention that the last time we had this discussion we posted a couple examples of the “Tom” big comic assemblage of SFPC mini-strips; I think including an instance of the crazy mail-in offers sidebar.

    My mild exception is that I like the effect when in the separate daily SFPC he will publish instances from the same mini-comic several days in a row. I admit I can tire of the Idiot Time-Traveler quickly, but think 3 or 4 consecutive days may be the right length to develop variations on The Epic/Brutal Report. … And that I think one wouldn’t want to see those gathered together as a “Tom”.

  11. As the Andertoons comic reminds me, strange things can happen with graphics during weather segment broadcasts. I was reminded of David Letterman’s early television career as a weatherman. Skip to the 1:00 mark here for his ad-libbed commentary regarding a satellite map image that was apparently missing a border line between two states.

  12. …and the “Meta” island gag reminds me of something that might occur in a Dark Side Of The Horse comic.

  13. Thanks, Mitch. I used to get Super-Fun-Pak Comix in my feed – I’ll have to see why it stopped.

  14. I don’t really know how they can keep the first down line above the field but below the players, but two possibilities are the color of the field or motion. If the player were to stand there long enough and be still enough, perhaps the line would end being over them. There is technology out there for accomplishing such a thing if you’d like to get your selfie in front of an icon of some sort and make it look like you aren’t 1 in a crowd of hundreds.

  15. Grawlix,

    “…and the “Meta” island gag reminds me of something that might occur in a Dark Side Of The Horse comic.”

    Or a Winnie the Pooh book.

  16. Just my luck, someone finally asks a question in my area of expertise, and I don’t see it until 2 days later. Oh, well… guess I’ll just answer anyway. 🙂 The three primary colors of light are Red, Green, and Blue (RGB)*. Any one of those three colors can be used for chromakey. Red is virtually never used, because there is a lot of red in human skin tone. When I started in television more than 40 years ago, blue was the usual chromakey color. As we got into the 1980s, green became the favored color, mostly because people owned a lot more blue clothing than green. When you chromakey something on a greenscreen, everything green in the picture is replaced by the background image, such as a weathermap. If your weathercaster is wearing a green tie, they will have a hole in their chest where the map shows through. This is not generally the effect you want, as it’s a distraction from the information being presented. We did have a weather guy who liked pulling chromakey stunts on Halloween, such as wearing a green bodysuit so all you’d see would be a floating head and hands in front of the map. Eventually, of course, management put the kibosh on such pranks. (He was also the guy who one time reported, “In Hell, Michigan the temperature is 18 degrees Fahrenheit. But it’s colder than Hell here.”)
    *The three secondary colors of light are Cyan, Magenta, and Yellow – not that anyone really cares.

  17. Danv, do you know how the first-down line works? TedD suggested motion might be a factor, and I can sort of imagine the algorithm comparing a few adjacent frames and excluding the ones that change. The green grass isn’t tall enough to blow in the wind, so that probably wouldn’t thwart the motion scheme. Of course the camera is often moving, so the algorithm would have to compensate for that.

    This reminds me of a couple of decades ago when Fox had the glowing puck in its hockey telecasts, and it would show up “through” the boards.

  18. We had a local meteorologist who one evening wore a scarf that had a few highlights in green. So there were a few shifting holes around her neck that was weirdly disconcerting.

  19. Thank you, DanV!

    After reading your notes I realized I once knew that term ChromaKey but had forgotten it. In common parlance today people seem to just say “green screen” all the time. (Or “background substitution” or equivalent descriptive term, if “green screen”is needed to talk about the literal green screen that might be used.)

    I was working with a friend on getting used to using Zoom. When we got to the “substitute background” part it noted that would be easier if you actually had a green screen, otherwise you needed to add in a plug-in that would be a little more computationally intensive and not all installations would be able to use it. (It turned out mine was fine but my friend”s was not.) She kept insisting “What do they mean, if you have green screen? Isn’t that what we are turning on in the settings, right now?”. She took the term to mean the software process of background substitution, whether from ChromaKey or otherwise — but they were asking if you could hang up a literal, physical, green background.

    (If you don’t have a literal green physical background, it computes outlines and so on to distinguish figure and background. That’s why it can shimmer uncertainly at the border, and why your cat walking across between you and the camera will confusingly only show parts.)

  20. Dan V – and the secondary colors are the ink colors for ink jet printers.

    I am presuming the primary colors for light are different than the general primary colors as we were taught red, blue, yellow.

  21. The head weatherman/person (he is a man and there are two women in addition the two men who do the weather reports) who does the CBS/Channel 2 weather reports has a barn on his home property which has been made into his weather center and has a green screen. The other day he gave a short tour of the barn and the setup so the green screen was shown.

    I will say the green screen was much better behaved than his 2 daughters, The green screen stood there and did nothing. In one of his early news reports from his barn he had his two rather young daughters all dressed up to appear on camera. He introduced them and they were on camera – but when they were then supposed to sit quietly while he did the actual report – well, young children like to say daddy and he had to pick up the younger one while the older one stood there grabbing on to him (no, not there). The channel has been running clips of him and his daughters which means they have gotten good mileage out of this.

  22. Having just been reminded, here, by DanV, of the term ChromaKey and its related terminology of “blue screen” and “green screen”, I naturally came across somebody using the term in conversation, and in the way lexicographers would love, linking the term and its meaning.

    I still am very old fashioned in how I listen to podcasts. Maybe some that are really radio shows in the first place I will hear as live feed, i.e. by listening to the radio. But otherwise I don’t use anything modern like a phone app to download and play at the same time (Apple Podcasts, Stitcher, now Spotify even), nor listen from the |> play button on a website, unless there is no other way. Instead, I just use the (now unsupported) iTunes program to subscribe and download to my computer, organize into playlists, and load onto my physical dedicated iPod Classic device. If I want to hear just one episode of a podcast I don’t subscribe to, maybe I can find it in the iTunes store and get just that episode; or from a website I can use “Download” instead of “Play” , save a file to my computer, and then import it into iTunes, and tell iTunes the genre is Podcast. (I can’t believe that the NPR Puzzle segment with Will Shortz is not on the iTunes store!)

    HOWEVER, to share such here, I will use a URL which is like using a Play button from the website; and that is in fact how I was just listening to find the URL and timing. If the built in start time doesn’t work, I am trying to share a passage starting at 00:21:38, and with “ChromaKey” and “green screen” coming in at 00:23:24.


    This is from a podcast called “The Next Track” (which is on iTunes, and I may end up adding a supscription) and the guest was Michael Connelly, crime fiction writer whose books underlie the TV series “Bosch” . I was actually searching “Music from Bosch” and did at some point find the hot jazz theme “Can’t Let Go” by Caught A Ghost (unaccountably “The band identifies themselves as an indie electro soul band. Their sound is a modern take on blue eyed soul; the tracks feature elements of classic Motown and Stax/Volt compositions with influences from dubstep, 90s rap, and contemporary electronica”). But among other results was this podcast episode with the interview. It turns out to say nothing about the theme music; but has interesting discussion of what a writer is doing when putting mentions of particular music in books or films, and how that connects to their own tastes or what they listen to while writing. Connelly says he was more of a rock / blues guy (or maybe the blues part came just from the hosts) but decided Bosch should be a jazz listener and asked all his expert friends for ideas of what to choose, to listen to himswlf and to write that Bosch was listening to.

  23. (I think that link works to take you to the web page and position the audio at the selected time, but then it is up to you to press the play button.)
    Meanwhile I transcribed a little:

    Host: …And I saw the house [from “Heat”] and I thought, Oh they’ve just got the house in the studio with a ChromaKey screen behind it — that’s not a real house.
    Connelly: No, they did use the same, you’re right, they did use the uh, whatever they called it back then, ChromaKey, whatever —
    Host: Green screen

  24. @ Meryl A – “I am presuming the primary colors for light are different than the general primary colors as we were taught red, blue, yellow.
    That’s exactly right. The difference is that light works with “additive” principles (R+G+B=White), whereas with perfect “subtractive” pigments, Red+Yellow+Blue would (theoretically) produce “black”. In practice (with most paints, crayons, etc.) the result is a muddy grayish brown.

  25. I had the impression that the subtractive primary colors (for pigments for example), while they used to be called “red, blue, yellow” in crayon sets and school painting practice, are actually the colors we think of as the main complementaries in light — “red” was actually magenta (comp. of green from RGB), “blue” was actually cyan (comp. of red from RGB), and “yellow” is indeed yellow (comp. of blue from RGB).

    That’s what I’ve heard. But, truth to tell, if I look at, say, a crayon mark from one labelled “red” it does look to me pretty red, not magenta. Ah well, so much for education and theory.

  26. I just now encountered this story, which seems relevant to the green/blue screen discussion: digg.com/video/the-mandalorian-used-virtual-led-sets-over-green-screen-for-special-effects

  27. Very interesting!

    I misread the title and misunderstood some of the narration for a while, as I took “over” to be a plain spatial preposition. so if the LED sets were over the green screens, would the green screens be under the LED sets? They didn’t look set up that way. Oh!, okay, they were choosing one -over- the other. ….

    It was cool that they included a call back to “process shot” technology, in those scenes of Sean Connery driving.

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