Color Photos from a Black and White Camera


In a previous video I did on the Connectix
Quickcam, the first ever webcam for personal computers, I showed a technique for capturing
color stills from an otherwise black and white camera. A lot of people were totally blown away by
this sorcery and wanted more information about it. So, I had promised a more in-depth explanation
of this process in a later video, and well, here we are. And, this process is actually not new. In fact, it was first proposed by James Clerk
Maxwell as early as 1855. However, it didn’t see a lot of practical
use until the early 1900s. Russian Chemist Sergey Prokudin-Gorsky helped
to popularize the idea around 1906. He used a regular black and white camera of
the era, and placed a color filter in front of the lens. In this case, a red color filter will block
all light that is not red. If you were to look through the color filter
the parrot would look sort of like this. Of course, some colors like white, purple,
and brown also contain red light. But colors like blue and green would appear
as black. Of course, the film in the camera is still
black and white so it would actually record the image like this. So, if you consider doing this 3 times with
all 3 primary colors, the parrot would look more like this. And of course, on the black and white film
it would look like this. So even though the film itself is not in color,
you still have the 3 representations necessary to reconstruct the color image. But how did Sergey display the photos? Well, he created a special slide projector
that projected three slides at the same time, each one using a different color of light. And so he could place the 3 black and white
photos in the projector, and the red, green, and blue light would reconstruct the color
image on the projector screen. And using this method, he actually took some
pretty amazing photographs. It’s hard to believe that these photos are
over 110 years old. And, of course, this concept is not exactly
considered outdated either, because most of your really high end professional cameras
still use the same concept. They have some cleverly shaped prisms, so
that when the light comes through the lens, it is broken into red, green, and blue light
like this. And then there are 3 separate image sensors
to pick up the light, and each of these sensors is in fact a black and white, or monochrome
sensor. So, I wanted to experiment with this concept
a little more, but I wanted a camera with at least a little bit better quality. So, I picked up this old black and white security
camera, which outputs a composite video signal. So I can use my laptop with a video capture
device to grab the images. This camera requires 24 Volts Ac, so I’ll
need to wire up this A/C adapter to power it. The camera has essentially 3 settings, you
have aperture control here, then zoom here in the middle, and focus here at the tip. So, this is what the camera sees. And I’ll need something to take a picture
of. I’ll use this little Pacman figure. Actually, I’ll give him the company of Ms.
Pacman as well. And just for a little extra color, I’ll
add in Mr. Meeseeks. So, I’ll just hold the color filters one
at a time in front of the camera. When I use the red color filter you can immediately
see that Mr. Meeseeks turned dark because he’s mostly blue. OK, so how do we take these 3 grayscale images
and turn them into a single color photo? Well, there are many programs out there which
can do it. I’ll demonstrate this using Gimp. So here are the 3 individual grayscale photos
and I’ll just drag them into Gimp. And there we go. So, let me re-arrange these a bit. So yeah, here’s the red, then the green,
and the blue. And you should be able to tell some difference
in brightness, for example, on PacMan here, that he appears darker in the blue image. Anyway, so how you combine these is you go
to colors, then components, then compose. Then this little dialog pops up. Obviously we want to use the RGB method. Then I just need to select the correct photo
to use for each channel here. And then, viola! There’s my color photo. It probably wouldn’t hurt to increase the
saturation some. I think the color filters I have are not 100%
pure, so they allow some light to come in from other colors, which means the separation
isn’t perfect, but I would imagine increasing the saturation like this should more or less
compensate. Well, let’s try another one. This is some fake decorative flowers. They look pretty plain here in black and white. But, I was able to get this photo using the
filters. And, how about these little mini arcades. I need to tighten up the focus. Ok, let’s see what we can get from this. There we go! Now, let’s try this unsolved Rubik’s cube. In fact, I’ll mix it up a little more. In fact, I’ll also add in the Rubiks Snake. I’m going to straighten that up just a bit. And there we go! This came out beautiful! OK, so I wanted to try this on a human subject. My daughter’s friend Jordyn volunteered
to be my guinea pig, or glamour model, however you want to look at it. The trick is, she’ll have to stay extremely
still while I take the 3 separate photos. And here are the 3 photos. However, combining them together didn’t
work out that great, as you can see a lot of color fringing down the left and right
of her arms and face. This is because she moved ever so slightly
during the take. Also this is a bit overexposed. So I tried closing the aperture some to darken
the image. This camera doesn’t have very good dynamic
range. Anyway, that resulted in more facial features,
but added some graininess to it. And despite several attempts, we were never
able to get a perfectly clear shot due to Jordyn having moved at least some between
captures. I decided to try this outdoors, which was
actually quite challenging because I needed to carry a laptop with me, along with a portable
power unit so I could plug in the camera to get the 24 volts AC power. We went to the local town center here in Kennedale
and I setup the laptop and camera. I had both of the girls pose for the camera. But one of the biggest problems was getting
the focus right because the sun was washing out the screen on my laptop and I just couldn’t
see any detail. The interesting thing is, the final photos
seem to have very little color to them. And I was quite perplexed by this. And the color they do have seems to be mostly
from sun glare on the different color filters, which I couldn’t see while taking the photos
due to the laptop screen. Interestingly enough, this clock tower probably
came out better than any of them, despite the moving clouds and the wind blowing the
plants and trees. And here’s the final color image from this. However, I was able to determine at least
one of the problems I was having. You see, this camera picks up a good deal
of both ultraviolet and infrared light, along with the visible spectrum. And that’s not a flaw, it was actually designed
to do that because it’s a security camera and that way it would have better light pickup
under low light conditions. So I took my little filters and tested them
with this UV flashlight. As you can see the camera picks up the UV
quite well, but you can see the filter blocks most of it. So that’s good. But what about infrared? I tried this remote control and as you can
see the filter does not block any of it. Of course, the filter probably wasn’t designed
with that in mind since most cameras would probably have some kind of infrared blocking
device already in the camera. It just so happens this one does not. So, I think if I were to figure out some way
to block the infrared light, either inside this camera or outside the lens, I think I
could make these photos look a lot better. You see, the reason that this picture has
so little color is that there is a lot of infrared light outdoors and all of that light
got through all 3 color filters, where as the indoor photos came out better because
I have LED lighting in the house, which doesn’t emit much infrared light in the first place. Anyway, it gives me a lot of respect for Sergei
Gorskii because he was able to take these magnificent photos back in 1906 to 1912 using
this same technique, long before color photography was really a thing. And what’s more amazing is that his subjects
were able to remain so completely still. Of course, not all of them because if you
look at this photo, you’ll notice this one girl was apparently not able to remain completely
still because you can see the color fringing around her. So, I propose a new photography challenge. I mean, why challenge yourself with film or
instamatic, or gameboy cameras when you can challenge yourself with a black and white
security camera. There you go, so once you take some masterpieces
with one of these bad boys, send me the result and let me see what you did. Otherwise, until then, thanks for watching.

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