Prism photography is a fun way to add some creative effects to your photos. From rainbow colours, to dreamy looks and reflections.
You can even use it to take out unwanted elements from your photo. All that without Photoshop or post processing.
Another advantage is that prisms are affordable and they fit in almost any bag.
Here’s our guide on using prisms for creative photo effects.
What Do You Need for Prism Photography
I have a plain 15cm triangular prism. You can use other sizes for glass prism photography. But you can hold onto the longer ones more easily.
You can use any camera for this type of photography. I even took a few photos with my phone.
If you have a lens with big apertures you will get smoother effects – try 24mm, 35mm and 50mm lenses.
Make sure you have a cloth nearby to clean any fingerprints.
How Does a Prism Work
A prism is a transparent object that refracts light and at least two of its sides has an angle between them. When light moves from one medium into another (in our case from the air into the glass), it causes refraction.
This makes it change its direction.
A ray of light is made up of light in many wavelengths. Each of those passes through the prism with more or less resistance than the other light waves.
The different wavelengths that normally travel together get dispersed. And we see them separately, as a rainbow.
How to Photograph Through a Prism
Working with prism photography requires learning by trial and error and some guesswork. There are many changing factors that affect the end result. These include the size and shape of the prism, the angle of the light, etc.
Every time you want to work with the prism you need to place it up close to the lens in the area of the frame where you want the effect to be.
Then move and rotate the prism slowly to investigate the effects you can create and how to get them.
Switch to Manual Mode to Find a Focus Point
Have you ever tried to take a photo through a glass using auto-focus? The camera is unable to find a focus point. It ends up refocusing continuously without getting anything sharp in the frame.
This is because auto focus uses visual cues based on light contrast to sense where to focus. When shooting through glass, in addition to our subject, the camera sees many other elements.
Reflections, fingerprints and other imperfections appear in the foreground and the camera tries to focus on them.
Even if you are not covering the whole lens with the prism, your camera might go a bit crazy, doing this annoying search for a focus point.
This is why you should switch to manual focus.
You can also first use auto-focus without the prism. While maintaining the focus point, switch to manual, place the prism and take the shot.
A Small Aperture Will Make the Prism Effect Smoother
You can do prism photography with any lens you have, but you should take a few things into account.
Using small apertures (f1.8 to f 3.5) will make the transition between the prism covered part of the lens and the uncovered part a lot smoother.
I took this photo without a prism and an aperture of f/2.5
Using the prism with the same aperture of f/2.5 I added a subtle effect in the left side of the image.
This is a matter of taste. If you like to have a stronger contrast between the two parts, you can use bigger f-values. Then you also need to take into account that it will affect your depth of field.
If you use a bigger f-value you will have a larger depth of field, so the background will be sharper.
This could be a good thing or a bad thing, depending on what kind of effects you want the photo to have.
This time I used an aperture of f/10. As you can see the contrast between the prism and the rest of the image is already visible and the background is sharp.
Use the Live View Display to Protect Your Eyes
When taking photos and playing around with the prism, it is easy to forget that we are redirecting light directly into our lens.
This light can get really intense. If you are looking through the eyepiece, it can have the same effect as looking directly at the sun.
Be on the safe side and switch to Live View.
How to Create Rainbow Photo Effects
To create rainbow photo effects you need to place one of the prism’s edges towards the camera. Move and rotate the prism to explore the distortions until the rainbows appear.
In my explorations I saw you can create two effects. You can take a photo through the prism. Rainbows will appear along the borders of objects in your image.
Or you can use the prism to cast a rainbow upon your subject.
The first option gives a dreamiersurreal look to the photo.
The second option is more subtle and can work well for a lot of photos.
How to Create Mirror Images and Ghosts Using Reflections
One neat effect you can add with a prism is reflections. Place the prism on the lens and move it until the reflections come to view.
You might need to try different reflections. Place the prism on different areas of the lens or change its orientation and angle.
You can create doubles of your models. This works great for kids, it makes them laugh a lot.
Or you can create a partial reflection that might look like water or glass reflections or ghosts.
Add Extra Light for Even More Creative Results
One of my favourite things to do with a prism is to use it to add some extra light to the image.
I placed the prism at one side/corner of the lens and twisted it until the frame got more light.
The problem here is that it is easy to overdo it and overexpose your image or even burn it. To avoid that, make sure you’re not covering too much of your lens with the prism.
Without using the prism
The same subject can look totally different by adding just a bit of light using the prism!
How to Use a Prism to Hide Clutter From the Background
When you’re taking a portrait, you should avoid any possible distracting elements. These include trash bins, big signs or bags. You can sometimes remove them or change your location or position to avoid them.
But what about the times you cannot do so? If you have a prism, you can use it here!
Place the prism on the lens. Move it around until the reflection, rainbow or extra light, manage to hide the unwanted element.
You’re not only hiding the undesired element from the background. You’re also adding a creative effect to your portrait.
Add a Dreamy Prism Photography Effect
Prism photography is perfect for creating dreamy looking photos. The distortions, light spots and rainbows help give a photo a unique mood.
Exaggerate the creative effects to make the image look more surrealistic.
You can eve place the prism so that it crosses the centre of the lens instead of the side.
This will make your photo look blurry and with strange colours, kind of like when you dream.
Blend Objects Together
I used to think that you have to use Photoshop to blend two images. But I was happy to discover that you can blend elements on the spot using the prism.
I know it is not the same as doing it in post-processing, but it’s good practice.
It allows you to experiment and see what will blend together well and what won’t. And above all, it is really fun!
Here I used the prism to blend the vegetation I had around with my model.
For blending you need to do the same as for creating mirror reflections.
Don’t catch your subject’s reflection. Instead, try to catch the reflections of other elements you have around.
This might be a tree, the clouds, a building and so on.
I used the prism to reflect other branches… and at the same time I added some extra light to the image
Create a Kaleidoscope Effect
If you want to play around even more, you can use the prism to create a kaleidoscope! To do so, you need to place the prism so that one of its bases faces the lens. Now just find something interesting to shoot.
For best results, make sure the prism covers as much of the lens as possible.
My DSLR with a 35mm lens was unable to focus through the glass. It kept refocusing on spots that weren’t covered by the prism. I used my phone’s camera instead.
It might be a bit challenging to hold both the prism and the phone at the same time. But with a bit of patience you will manage!
Prism photography is a great way to add creative effects to your photos. And you don’t even need to use Photoshop.
You can create dreamy images with some distortions, reflections and even rainbows.
You can also use it to add a bit more light to an image and even to get rid of unwanted elements from the background!
Getting the effects takes a little bit of trial and error, which makes the whole process playful and fun.
Experiment with different aperture values until you get the effects you like. And if your lens gets a bit crazy trying to focus, remember to switch to manual.
A note from Josh, ExpertPhotography's Photographer-In-Chief:
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