Riddick, a khajiit, and a gamer who put the gamma settings too high are sitting in a room. Somebody turns on a TV [technology (CRT, Plasma,...) is up to you], showing a surveillance camera footage but in a dark environment.

GUARD - Gentlemen, can you please help us identify any strange behavior on this screen ?

GAMER - Don't you have any sort of enhancing software to...

GUARD - Shut up, it invalidates this question...


RIDDICK - (smiling) You should be afraid of the dark, because you read this with my voice...

And you ? Do you think night vision capable creatures could enhance information given by a TV screen ?

Quick description for those who don't know these characters :

A Khajiit is a playable cat-like animal race in the role playing video game Skyrim. When selecting it at the beginning, the game says your character will have night vision.

Riddick is the hero of The chronicles of Riddick franchise performed by Vin Diesel. In the video game Escape from Butcher bay he gets the night vision power, but it is permanent so he has to wear special goggles to avoid strong light sources.

  • 4
    $\begingroup$ It depends on the surveillance camera. If the camera isn't able to record the information required, the Khajiit isn't able to see, because the information isn't there. On the other hand, if the camera is good enough, you don't need the Khajiit, because information can be made visible by software. $\endgroup$ – Alexander von Wernherr Dec 12 '16 at 7:40
  • $\begingroup$ @Alexander why don't you post this as an answer? $\endgroup$ – Mołot Dec 12 '16 at 7:42
  • $\begingroup$ I can, but it doesn't feel complete. $\endgroup$ – Alexander von Wernherr Dec 12 '16 at 7:43
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    $\begingroup$ It's not about enhancement. Information either is there, and scree is probably tuned to show it (that's the default option), or it isn't, and that's it. $\endgroup$ – Mołot Dec 12 '16 at 8:23
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    $\begingroup$ How is this related to worldbuilding? $\endgroup$ – Frostfyre Dec 12 '16 at 14:10

It would not work. The issue is noise. Each piece of equipment adds some amount of noise to the image. One can transfer the information into the digital domain to avoid adding more noise, but the instant you do, everything that was below the noise floor or quantization limits of the digital medium is completely removed.

The noise floors and quantization errors which are acceptable are carefully tuned to the capabilities of the viewer. If the screen and surveillance equipment was designed for human eyes, you won't see anything out of the ordinary.

Now if the equipment was overdesigned, one might be able to see things. If you used multimillion dollar calibrated camera equipment, 24-bit/channel data, and a screen which was designed to actually be able to convey all of that content, then those with more capable eyesight might be able to see things. This is similar to how most people are cool with the sound that comes out of their crummy little earbuds when they play their ultra-compressed MP3s, while others can listen to their $100,000 sound system with studio monitors and the raw DAT tapes and tell you which recording studio the tape came from just by analyzing the sound. However, surveillance footage rarely comes from such high quality equipment.

Of course, you forgot the one person in the room who could pull information from the surveillance footage that nobody else could. Shame on you for not introducing him:

Sherlock -- See! There! When he held his watch up to check the time, you can see that the date is the 29th. You can also see that his watch is one hour ahead of all of the other clocks in the room. This could be attributed to carelessness, but note the attention he gives to the clock that is 1 minute ahead from all the others. Clearly this is not a man who makes such a mistake, ergo he is from a different time zone. But out of the 4,326 clock stores in the United States, none of them are close enough to a time zone border for a man such as this to not adjust his watch. Now look at his skin. Rough, dry, this man lives in a very hot and dry part of the country. Now, remember the date! It's the 29th of March! Daylight Savings! This man hasn't left his timezone, he's still in it! Arizona does not observe Daylight Savings, but Utah does! He's from Arizona, and visiting the only clock store within 8 miles of the border is Bill and Ted's Excelent Clock shop in Big Water, Utah. Our killer is there, now go out there and arrest him!

Never try to solve with nigh vision what can be solved by merely incorporating the clues in front of you! Deduction!

  • $\begingroup$ Well, my staff LOOKS for behaviour, while Sherlock analyses it. If Sherlock could SEE if the guy looking at its watch in the dark then OK. $\endgroup$ – Goufalite Dec 13 '16 at 7:06
  • $\begingroup$ The point of bringing in Sherlock is to point out that mere physical ability to detect photons is not the only part of vision which matters. The ability to put things together and draw conclusions from details which were visible but ignored is just as powerful. $\endgroup$ – Cort Ammon Dec 13 '16 at 14:21


Human devices are built for human eyes. Human devices have high sensibility to Red, Green and Blue colors.

Thus, human devices are made of "dots", each of them formed by 3 sections. Each of the section is illuminated with one of the Red, Green and Blue colors.

Which brings us to the issue of how the images are stored and transmitted. Either analog or digital, the signal is just a composition of Red, Green and Blue intensities1.

Simply put, since the only information usable by humans is in the visible range2, regular hardware and software will only deal with visible light and will ignore any other input, even if it can be captured.

1In some digital formats there is a value for "alpha" or transparency, but obviously when the image is reproduced this value is not shown (either shows the background, the foreground, or a composition of both)

2What a nice coincidence!!.. Oh, wait...

  • $\begingroup$ Not true. Digital cameras, for instance, have a filter to block infrared, because the camera's photodetector is sensitive to that. So it's perfectly possible to build cameras (and display devices, if you have infrared-sensitive people like the khajiit on your staff). Astronomers & space probes do this all the time, converting various non-visible (to humans) wavelengths to false colors. $\endgroup$ – jamesqf Dec 12 '16 at 19:33
  • $\begingroup$ @jamesqf I was meaning regular, off the shelf cameras. Note the point about "no software enhancement"; if we consider custom built cameras then all the considerations are off (since these would include their own software, their own display formats, etc. $\endgroup$ – SJuan76 Dec 12 '16 at 19:47
  • $\begingroup$ But it would be quite useful for a surveillance camera to do infrared, and they are available off-the-shelf. Search for "infrared surveillance camera" on Amazon or eBay. $\endgroup$ – jamesqf Dec 13 '16 at 4:01
  • $\begingroup$ @jamesqf But those do not send an IR signal, but a RGB signal "representing" the IR input. The OP wants to know if his TV/monitor is sending IR info that someone (Riddick) could use to "see" the original IR image. But the input of the monitor has no IR info, and any IR radiation from the monitor is just due to the heat caused by the monitor operation. Additionally, the engineers that designed the monitor will have worked very hard to reduce any IR signature (as it means wasted energy). $\endgroup$ – SJuan76 Dec 13 '16 at 8:29
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    $\begingroup$ @jamesqf We are not given such details. The basic point is not that we are in a world with such people, but if we have regular cameras and TVs that could capture and display something that Normal color vision could not see, but something classifiable as night vision could. The answer is of course no, because its not built for that. Only custom made stuff could do that, and we know that because we can and do use much of the ER spectrum, from X-Ray to Radio, in tech now. $\endgroup$ – Ryan Dec 13 '16 at 18:41

It depends on the surveillance camera.

If the camera isn't able to record the information required, the Khajiit isn't able to see, because the information isn't there.

You can check out this Link to see how a cat(-person) sees the world.

The two types of photoreceptor cells are known as rods and cones. Rods are responsible for peripheral and night vision. They detect brightness and shades of gray. Cones are responsible for day vision and color perception.

Cats (and dogs) have a high concentration of rod receptors and a low concentration of cone receptors. Humans have the opposite, which why we can't see as well at night but can detect colors better.

So, your catperson may be able to see changes in brightness and grayscale, IF the information can be recorded.

  • $\begingroup$ I agree on the grayscale vision, but if I show a dark picture (with all the information as the night pictures of the link) to my cat on my PC monitor, will it be troubled by the backlight of the screen for example ? $\endgroup$ – Goufalite Dec 12 '16 at 10:13
  • $\begingroup$ You might want to add that not only the camera needs to be sophisticated enough to record additional information, but the screen also needs to reproduce it correctly. $\endgroup$ – Annonymus Dec 12 '16 at 18:02


Human have night vision, but it is relatively poor. https://en.wikipedia.org/wiki/Rod_cell

The rod cells react only in a one way to light, so they do not register the colour. If your surveillance device would be sensitive enough, it could be that the screen could send such low amount of light that it would be seen only by an animal.

The camera is not the problem: https://en.wikipedia.org/wiki/Night_vision Humans amplify the light in their applications.

The problem is that humans have no such technology for screens, because they have no need to show something that will not be seen. But if analog signals would still be used, then there could be a case that the screen would emit sensitive signal enough for only animals.

  • $\begingroup$ «analogical signals » ? $\endgroup$ – JDługosz Dec 13 '16 at 8:28
  • $\begingroup$ I suppose he speaks about a TV pixel producing infrared. I don't know if it is possible... $\endgroup$ – Goufalite Dec 13 '16 at 13:15
  • $\begingroup$ It does not need to be infrared. Animals with night vision have more rod cells. Humans have those too. Extremely high quality analog signal might be able to replicate the non-amplified "night vision" signal on screen. Analog vs. digital is here the thing. $\endgroup$ – user3644640 Dec 13 '16 at 13:40

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