A problem using chroma-key can be that the color you're using - usually green - can't be in the shot, or it will be superimposed with the image you're chroma-keying.
BTW originally chroma-key used blue screens, but (according to legend) they had to change it to green because an early user was CBS News, and Walter Cronkite refused to stop wearing blue suits.
Why limit yourself to scenery?
Why not just proect a hologram of someone else's layout, and save yourself the money and time?
JetrockOr, you can use an even smaller video screen to simulate activity within a building window...
Just the opposite of huge backdrops, but no less cool...
Dunno, I think that I will stick with photo based backdrops.
Rich
Alton Junction
JetrockA suitable pico projector might be very useful to simulate a drive-in movie theater (there was an old MR with an article about using a Super 8 projector with some mirrors).
Someone, Cornerstone I think, made a model of a drive-in theater that was supposed to use an I-pad for the screen.
-Kevin
Living the dream.
Video projection might not be useful for a backdrop, but a suitable pico projector might be very useful to simulate a drive-in movie theater (there was an old MR with an article about using a Super 8 projector with some mirrors, but even a tiny pico would be suitable for a small HO scale "passion pit."
Or, you can use an even smaller video screen to simulate activity within a building window--or even a movie theater--using a cheap micro sized video player with a 2" or so screen Like this one:
If you had a few feet of empty wall, it might make an interesting scene. A harbor might work, or even an off-layout airport.
It takes an iron man to play with a toy iron horse.
gmpullmanWhile you wouldn't see anything without video processing, I have followed a few videos of this fellow who uses "Chroma-Key" green screen video processing to "project" his backrounds.
When my youngest daughter lived at home, we painted one wall in her bedroom "green screen" green so she could add backgrounds to her amateur modeling shots.
When I set up my 30 by 30 model photo studio in there, I thought I would add backgrounds to my photographs using the green screen, but I never learned how to do it.
While you wouldn't see anything without video processing, I have followed a few videos of this fellow who uses "Chroma-Key" green screen video processing to "project" his backrounds.
There are a few shadow artifacts but I still think it is a pretty neat use of the technology. Something that was out of the reach of the average video amatuer a few years ago is now common and cheap.
Regards, Ed
RRRR - Rat Room Rail RoadHas anyone done this yet? I just purchased a projector and looking for cloud videos to project and it would be great to see how others accomplished this!
I don't know of anyone doing this with a projector.
I did see an N-Scale module at a train show in Georgia that had a TV or Computer Monitor as a backdrop, and it was accomplished very effectively.
Has anyone done this yet? I just purchased a projector and looking for cloud videos to project and it would be great to see how others accomplished this!
Work Hard! Train Hard!
The Future's so bright we gotta wear OLEDs. Or whatever thin-film flexible low-energy durable display material emerges for use on large span background surfaces. I'd love to take full credit as coming up with this idea, but I'm more likely the 38,849,512th person to have done so...Hmmm, combining OLED displays with real-time shift-tilt imaging so that our models seemless merge into the background, could be interesting...
(I give up, the forum is once again refusing to internally link to a MR thread for me no matter what. Perhaps others may have greater success: http://cs.trains.com/mrr/f/88/p/172787/1897336.aspx#1897336)
wjstix MR had an article many years ago (maybe c.1980?) on using front-screen projections as a backdrop when photographing dioramas. The idea was that the part of the image (like from a slide projector) that fell on the scenery and train would be broken up enough that you couldn't see the projected image except on the background screen. I don't recall anything about it being used 'live' on a layout. However as flat screen TVs become better and cheaper the day may come where they could be used as part of a backdrop.
MR had an article many years ago (maybe c.1980?) on using front-screen projections as a backdrop when photographing dioramas. The idea was that the part of the image (like from a slide projector) that fell on the scenery and train would be broken up enough that you couldn't see the projected image except on the background screen.
I don't recall anything about it being used 'live' on a layout. However as flat screen TVs become better and cheaper the day may come where they could be used as part of a backdrop.
Back when professional photographers and videographers worked with film, Front projection was often used to add a false background. It required a very carefully aligned, specially designed, highly reflective screen behind the person or object and a beam splitter on the camera to be sure that the projected image was perfectly on axis. If you looked through the camera view finder you could see the combined scene. If you stood beside the camera, you saw a blank backdrop. It worked great for photography, but could not be used in a display. The technology was rendered obsolete by digital CGI.
http://en.wikipedia.org/wiki/Front_projection_effect
Dave
Lackawanna Route of the Phoebe Snow
The front-screen projection used in 2001 A Space Odyssey used a retro-reflective screen- somewhat like the highway signs that send a bright reflection of letters back directly at your car. An ordinary screen diffuses light somewhat. A mirror sends a projected image that comes from off-center at an angle on one side at the same angle to the other side. The retroflective screen sends the light or image directly back towards its source. The projector goes through a beam splitter right in front of the taking camera lens. Most observers on the film set couldn't see the image at all, but the camera picks up a very bright image.
So like the Chroma-Key used in the video studio, this would not have much application to producing an effect for a live viewer.
I HAVE seen a projection system used used effectively on a layout by Corpus Christi's Jack Gruen in the early 1970s. He started a projector- which didn't make much of an impression with the room fully lighted. But the image was churning clouds and lightning. As the room lighting came down, the thunderstorm in the mountains took over the scene for a few minutes, then went away as the weather cleared.
Neat. But a special effect for special circumstances.
On another forum, someone asked how to model a UFO. I suggested some kind of holographic projection that would add to the not-quite-there experience of an intrusion from another dimension.
I wonder if a projection JUST for clouds and white smoke (everything else in the projected image opaque black) would work with more or less normal lighting.
Phoebe Vet A computer monitor might but it would be incredibly difficult to hide in the scene.
A computer monitor might but it would be incredibly difficult to hide in the scene.
The top bezel would be nearly impossible to deal with, yeah.
I've been curious if one could extract the LCD out of an older cell phone (like the ENV Touch or something that had a smartphone-type large hires screen), run much longer wires to it, and remount the screen as one of those LED array style billboards, with the guts of the phone down in the benchwork nethers.
DSchmitt Technique based on method used for filming moon scenes for the movie 2001 A Space Odyssey.
All of the Africa scenes at the beginning of that movie were shot on a set. Slides of the African landscape were projected onto a huge screen.
Steve S
Phoebe VetThe system you are describing in the last paragraph is called Chromakey. It uses a computer to drop out a single primary color, usually blue or green, and substitutes a separate scene. It is not visible to the people physically present. That is why the person needs a monitor to see what they are doing. It is not a system that will work as a background. Projection only works in a dark room. A computer monitor might but it would be incredibly difficult to hide in the scene.
Maybe what I saw was about making a video using that method.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
DSchmitt Not really a farfetched idea: December 1969 pg 76 article on using projected slide photos as back drop for dioramas. Technique based on method used for filming moon scenes for the movie 2001 A Space Odyssey. Somewhere within the last year or so I saw an article or video about using projected backdrops behind running trains. Same method as used by many TV stations behind reporters in the studeo. Some cars because of their color were not visible when running in front of backdrop. Same as happens on TV wnen the reporter wears the wrong color.
Not really a farfetched idea:
December 1969 pg 76 article on using projected slide photos as back drop for dioramas. Technique based on method used for filming moon scenes for the movie 2001 A Space Odyssey.
Somewhere within the last year or so I saw an article or video about using projected backdrops behind running trains. Same method as used by many TV stations behind reporters in the studeo. Some cars because of their color were not visible when running in front of backdrop. Same as happens on TV wnen the reporter wears the wrong color.
40 years ago, movie & TV studios used front and rear projection. If you look at old movies that used that tecnology, it was poor quality and very obvious.
The system you are describing in the last paragraph is called Chromakey. It uses a computer to drop out a single primary color, usually blue or green, and substitutes a separate scene. It is not visible to the people physically present. That is why the person needs a monitor to see what they are doing. It is not a system that will work as a background. Projection only works in a dark room. A computer monitor might but it would be incredibly difficult to hide in the scene.
We have seen people use mirrors on a layout to extend the depth of field. Setting up a cheap flat screen monitor, perhaps between two buildings would work (according to the LION) just perfectl XXXXX00000 WINDOWS HAS STOPPED WORKING, YOUR SKY IS FALLING AND ALL OF YOUR TRAINS HAVE BEEN DERAILED BY A GIANT BUG.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Honestly, I can think of no positives and a laundry list of negatives.
The first being that if you, physically, are going to block the projection almost constantly and the second being that unless the room is almost pitch black, the projection is too soft and washed out to be worth the cost and effort.
I suppose it could, but it would cast shadows. Maybe a digital monitor could work, stashed between two buildings.
They use those things in faux fireplaces and they look realistic enough in there. Either way, ewe would knead a computer to drive them, well maybe a tablet could do it.