Each of eyes captures an image with a slightly different viewpoint, and our brain puts them together calculating the distance between the object and ourselves. Something like the following:
The colors are used for illustration only. I wanted to show you there is an intersection of our sight, and there are some small parts which only each eye can see. You can easily illustrate this by looking in front of you and closing one eye at a time.
Today we'll be trying to recreate this using some crafty photographic and post-processing techniques!
Taking the Pictures
We can create an anaglyph by superimposing two 2D images. As you may have noticed, to create Stereoscopic 3D images we need two pictures of the same object taken with a small amount of separation (in the same way our eyes operate). We can achieve this by using two cameras side by side, or only one and moving its position horizontally.
There is a rule you may consider when taking this kind of picture. It says that the distance from the camera(s) to the object should be at least 30 times the distance between the centres of your lenses. For example, if the distance between your lenses is 2 inches (5,08 cm.) the distance to the object should be 60 inches (152,4 cm.) as 2 * 30 = 60.
But as with any rule, you should not be limited by it. Take it as a consideration and experiment yourself how you obtain the result you want. It is highly recommended to use a tripod since we need to take the pictures with almost no height variation.
Here are the couple of pictures we'll be using. It may seem they are exactly the same but I can assure you that they aren't. Now we can start creating our anaglyph...
It's Photoshop Time
I've tried to explain this section as clearly as possible, so it'll make sense whether or not you're a Photoshop expert!
Step 1: Setting Up the Size
In this case we can cut out a little bit the left part of both pictures. Select any picture and go to "Image > Canvas Size" (Win Ctrl+Alt+C / Mac Cmd+Opt+C).
A new window will appear, giving you the information about the current image size and the input option for the new size. I decided to have a square picture so I gave Width the same value of the current Height.
Now this is important, as we only want to cut out the left part of the picture be sure the anchor point is set to the right as the second image shows. Apply the same changes with the other picture.
Here's what we get:
Step 2: Turn to Grayscale
In case you are wondering - yes, we can make colour anaglyphs, which we will cover later on. But as a start, it's recommended to do a grayscale Red-Cyan anaglyph. To convert to grayscale, we'll just desaturate the image.
Go to "Image > Adjustments > Desaturate" (Win Ctrl+Shift+U / Mac Cmd+Shift+U).
Step 3: Preparing the Image
Select the right image with "Select > All" (Win Ctrl+A / Mac Cmd+A). Copy it "Edit > Copy" (Win Ctrl+C / Mac Cmd+C) and paste it over the left image "Edit > Paste" (Win Ctrl+V / Mac Cmd+V). Your layer order should look as follows:
Double click the left layer image Background and press Ok to unlock it. Its name should change to Layer 0.
Step 4: Changing the Color Channels
Select the right image (Layer 1). Double click it to open the layer styles options. Uncheck the R channel and press Ok. If you hide Layer 0 (by clicking the eye icon at the left of the mini image) you can see the image has turned Cyan.
Select Layer 0, double click it and uncheck the G and B channels then press Ok. If you hide Layer 1 you can see the image has turned red.
Unhide the layers, and the result should look as follows::
Thankfully we don't need to do any more adjustments; merge the images together, and the anaglyph is finished. I wanted to show you the basic steps with this example first since it was easy and direct, but sometimes we have some difficulties from start.
Let me explain some other steps to follow when these things happen next!
One of the main problems when shooting for anaglyphs is the height variation of the cameras. Using a tripod helps, but the floors aren't always regular so we need to do some additional adjustments.
Take a look at the following pictures:
While most of the components of the pictures are shared, the differences are pretty obvious in the borders. If we follow the previous steps the result would be the following:
You can't really appreciate anything. So let's start correcting this mess!
Step 5: Alignment
Look for an object that's easy to identify in both pictures, like the stop sign (sorry for blurring it out here, but it was covered in some slightly indecent graffiti!) Once you've chosen the object, move either one of the layers to fit over the other.
Step 6: Rotate if Needed
If the image hadn't fit, you may have to rotate it a little. Select one of the layers then go to "Edit > Free transform" (Win Ctrl+T / Mac Cmd+T). Move the mouse over any of the squares outside the picture, then hold down to rotate at will.
When you've done, click on the check mark to apply the change (or choose the symbol at the left of it to cancel).
Step 7: Other Objects to Reference
Choosing different reference objects can improve the final result. The following picture is from the left side and illustrates the three points I've chosen: the stop sign, the big tree and the garbage container at the back.
As the reference points are changing it's possible that we may need to rotate the images again to fit.
The picture below is the result from the first point. The sign, pole and box look fine but the rest of the items don't give you that feeling of depth we are looking for. Note the red and cyan parts that appeared at the sides as we try to fit the images.
The following picture was made taking the second reference point. It's an improvement from the picture above but gives you the feeling there might be a better result.
Finally the third result. In my opinion, this is the best of the three!
Step 8: Crop & Save
Next, let's get rid of those red and cyan parts. Select the Crop Tool (hotkey: "C"), mark the area you wish to conserve and press the Check button to accept the change.
This is how it looks like finished. Now save it and you are ready to share!
Show Me Color!
Now you understand the mechanics for elaborating anaglyphs, the only thing that varies from creating a grayscale and a color one is Step 2: Turning to grayscale.
Omit that step, and you'll get your color anaglyph. Take a look at our first example in color:
I had the opportunity to try two pieces of free software for achieving this effect, both of which are really easy to use - as easy as selecting the pictures and pressing a button!
Although I haven't used them much, they can be a decent alternative for those who don't own Photoshop. I've only tested them on Windows XP.
The first one is Anaglyph Maker which I found very easy to use. First, click over the Load Image buttons and select your images for the left and right sides.
You'll notice the images appear in the windows. To continue click "Make 3D Image":
The anaglyph will appear in the bigger window. As we saw before with this example we have to move the images before exporting the anaglyph. Use the buttons to displace the image and fit correctly. Unfortunately there is no rotation option.
Finally, we can save our anaglyph. You can save in BMP or JPG with various quality settings. There are two possibilities for saving your work, the first one is the anaglyph just made, the second one save both source images separated without creating the anaglyph. The program crops the images automatically, cutting off any cyan or red part left over.
There are other anaglyph options, for example the color one. Simply select which kind of anaglyph you desire from the options below the load image buttons.
The second software is StereoPhoto Maker. It has more options than the previous piece of software, but remains freely available. Load your images by going to "File > Open Left / Right images". You are asked to choose both at the same time.
Use the Auto function to let the program match the pictures. A small window will pop up showing the results.
Select the type of anaglyph you want - grayscale or color. Each of these have various relevant options like the previous software.
If you'd like to do manual adjustments go to "Adjust > Easy adjustment"
Here you'll find the most important features for manual adjustment, such as the possibility to move the pictures horizontally or vertically, rotate, and change their sizes.
The saving options are the same as the previous software. You can save the anaglyph or both images separated. This software also crops automatically.
Making Your Own Glasses
Time for some manual labor I'm afraid! Whether you can't find where to buy paper glasses, or just want to spend some minutes making your own, here's the list of materials we'll be working with:
- Thin cardboard (or any paper you consider will give a good rigid structure)
- Adhesive Tape
- Red cellophane paper
- Blue cellophane paper
- Scissors (or any other blade for paper cutting)
- Printer (just for printing the pdf)
- Glue (optional)
- Clips (optional)
Step 1: Print the glasses template provided with the tutorial. Advice: If you're not sure your printer can handle the width of thin cardboard, it's safer to print over regular paper and place it over the cardboard for the cutting.
Step 2: Cut the pieces and eyeholes. If you are using paper over cardboard, use some clips to avoid undesired mis-alignment!
Step 3: Cut the cellophane paper for each glass side. Note: If the cellophane is too thin, or the color isn't strong enough, you may have cut two pieces for each color and put them together (or cut a big one and fold it) to get a good effect.
Step 4: Tape the cellophane to the cardboard borders without interrupting the eyeholes visibility. Cyan / Blue to the right and red to the left side.
Step 5: Finish assembling the glasses parts.
Hopefully these should work perfectly with your anaglyph image, and let you see the full 3D effect of the final image!
Just an extra tip; sometimes it's difficult to preserve the height when shooting with one camera. To help remedy this, I use a skate board for easy horizontal movement!
I hope you had fun reading this tutorial and making your own anaglyphs. Best of luck with the process!