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Space Invaders 'reflector' cabinet question.
jukingeo:
--- Quote from: cosam on December 04, 2009, 03:46:53 am ---
Sorry, it's not my cab, just something I came across on the web. Maybe you can find some contact details on the site somewhere.
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Oh, that's OK. The pictures were actually more helpful when I got to look at them a 2nd time. I almost spend 45 mins studying the pictures last night and about 90% of my questions have been answered.
--- Quote ---I don't think there's any reason it'd have to be 45 degrees. All you need to do is make sure the monitor is reflected somewhere in the field of view of the player. If I were building it, I'd either make a mock-up and experiment, or make the end product adjustable (at least the angle of the mirror, if not the monitor too).
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Yes, it does matter that the angle of the mirror to the monitor is 45 degrees otherwise the image would be distorted. A 45 degree angle would preserve the reflected distances. Looking at a picture of the inside of one of the side panels does show this as I can clearly see where the mirror and monitor mounts are. Thus in short, I am seeing a cross section of the mountings. That is a HUGE help. Now, it does look like it is still a weird angle, but even though the monitor to mirror is critical that it is 45 degrees, what isn't critical is how the mirror is angled to player. So more then likely, Midway figured out what the optimal angle was to aim the video to the player and then just maintained the 45 degree lower angle to the monitor. In addition this would pitch the bottom corner of the monitor down, so it is less likely to be seen by the player (it is put out of the player's field of vision). So my gathering that as long as the monitor to mirror angle is in the SAME PLANE at 45 degrees, you could rotate that plane in any direction that is desired. So right there that did answer one big question.
It does also mean that I probably have to make the cabinet slightly larger than originally calculated to compensate for the rear downward angle of the monitor.
--- Quote ---I'm no expert on the subject, but I'd have thought the silvered side would be away from the viewer, just as it is on a regular mirror. It wouldn't exactly be rocket surgery to try both ways and see which looks best ;-)
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That is what I initially thought as well, but lately I am beginning to think otherwise. I have a one way mirror at work...the boss' window actually. I was playing around with it. If both rooms are lit on each side of the mirror, I cannot look into my boss' office, but he can look out into the main room. Likewise if I shut the lights off in his office. BUT I made a strange discovery that if I shut off the lights in the main room and leave the lights on in my boss' office, YOU CAN see in from the otherwise reflected side. It does look like you are looking through a tinted window, but you CAN see in.
As it stands, the backdrop in Space Invaders IS lit from a light. So that would mean the other side of the mirror must be as dark as possible. Have you ever wondered why Space Invaders has that HUGE bezel, but a small window to look in? Well, the bezel is preventing as much outside light from entering the cabinet as possible.
The monitor just is projecting a few areas of light on to the mirror, so it isn't enough to drown out the back image.
Thus my guess is that if the mirror was turned the other way around as I initially thought, the monitor display wouldn't be as clear and moreover a reflection of the light would be casted on the backdrop. So now I am thinking that the silvered side is facing forward.
Granted, as you put it, that is the rocket science approach and it would be simpler just to try the two way mirror each way.
Now, moving on to the next thing...the backdrop itself. Again looking carefully at the pictures I can see that there is a florescent light bulb in between the half round moon and the back of the cabinet. The person restoring the cabinet does show the backdrop, but not how it is mounted in the cabinet. I am assuming that the backdrop is mounted on the rear door of the cabinet and as such the light illuminates the backdrop. The half round "moon" must be a translucent material to allow the light to shine through lighting it up while masking the light from the viewer. If that is the case then ANOTHER question crops up. What KIND of florescent light is that? It looks like a standard white bulb...but could it be a blacklight bulb?
Geo
Kevin Mullins:
Blacklight - probably a blacklight "blue" bulb. (more intense UV, less "bright" than the white bulbs)
You're gonna make me go out and get my spare AD mirror and play with it now. :P
My complete AD is buried in storage, so I can't just go look at it.
I'm wanting to say the "mirrored" side is facing the artwork.
You'll know it's backwards because you will get a double image from the monitor, which I would think would be a reflection from the "mirror" and a second reflection from the glass itself. (theoretically speaking of course)
jukingeo:
--- Quote from: Kevin Mullins on December 04, 2009, 07:52:50 pm ---Blacklight - probably a blacklight "blue" bulb. (more intense UV, less "bright" than the white bulbs)
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--- Quote ---You're gonna make me go out and get my spare AD mirror and play with it now. :P
My complete AD is buried in storage, so I can't just go look at it.
I'm wanting to say the "mirrored" side is facing the artwork.
You'll know it's backwards because you will get a double image from the monitor, which I would think would be a reflection from the "mirror" and a second reflection from the glass itself. (theoretically speaking of course)
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Ahhh yes, I have thought of that too (actually read it somewhere) that you have to use a mirror with the silvered side on the outside or the side where the monitor is to avoid the double image. So that is another reason I am thinking the reflective side is on the monitor side. BUT, I could be wrong.
Edit:
Well, as it turns out everything just discussed could be all wrong. I came across this via an unrelated link on this site:
(Scroll out to 1:52)
Apparently there is such a thing called a HALF-Silvered mirror, in which you can see equally through both sides and it is also very reflective. So I am beginning to think this is the animal we are looking for.
So Kevin, if you don't mind I would appreciate it VERY much if you get a chance to take a look at that mirror. More then likely in a well lit room if you can see through both sides...then it is a half-silvered mirror and not a two way.
This is becoming VERY interesting!
2nd Edit:
Even some more interesting reading that supports my room lighting experiment with my boss' mirror:
http://www.howstuffworks.com/question421.htm
Geo
Bender:
--- Quote from: jukingeo on December 05, 2009, 01:39:38 am ---
--- Quote from: Kevin Mullins on December 04, 2009, 07:52:50 pm ---Blacklight - probably a blacklight "blue" bulb. (more intense UV, less "bright" than the white bulbs)
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--- Quote ---You're gonna make me go out and get my spare AD mirror and play with it now. :P
My complete AD is buried in storage, so I can't just go look at it.
I'm wanting to say the "mirrored" side is facing the artwork.
You'll know it's backwards because you will get a double image from the monitor, which I would think would be a reflection from the "mirror" and a second reflection from the glass itself. (theoretically speaking of course)
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Ahhh yes, I have thought of that too (actually read it somewhere) that you have to use a mirror with the silvered side on the outside or the side where the monitor is to avoid the double image. So that is another reason I am thinking the reflective side is on the monitor side. BUT, I could be wrong.
Geo
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I think Kevin mentioned the half-silver in the third post
Yeah, I think that's right your looking through to the artwork, in other words it's not reflected in the mirror at all, so there's no chance of a double image, where the monitor is what is reflected so the silver should be facing it to avoid the double image from the thickness of the glass
jukingeo:
--- Quote from: Bender on December 05, 2009, 01:56:55 am ---
I think Kevin mentioned the half-silver in the third post
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Yeah, you are right...he did. I guess I didn't pay it any mind because it was a term I was not familiar with. I am more used to one-way or two-way mirror. But after seeing the video and that fellow mentioned it too, it did get me thinking that unlike the mirrors used in games like Pac Man and Galaga, which is a true mirror, the mirror used in Space Invaders seems like a very reflective piece of glass and that is exactly what a half silvered mirror is.
--- Quote ---Yeah, I think that's right your looking through to the artwork, in other words it's not reflected in the mirror at all, so there's no chance of a double image, where the monitor is what is reflected so the silver should be facing it to avoid the double image from the thickness of the glass
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There has been much talk about that in other threads about making sure that if a mirror is broken in a reflection cabinet, that the replacement mirror has the silvering process done on the outside.
Geo