Projectors provide users with a large screen which enhances the viewing experience. However, this doesn’t mean they can be placed just about anywhere in your space.
For the best viewing experience, you need to calculate the right distance between your screen and your projector.
The throw distance of a projector depends on its lens. The projector lens may be wide-angle, telephoto, or a zoom lens.
Zoom lenses can be adjusted to project in either Wide or Tele mode. In this article, we will provide a detailed comparison of the two.
First, what exactly is the projector throw distance?
Quick Navigation
What is the Projector Throw Distance?
It is the distance from which the image is technically “thrown” onto the screen.
This distance determines the size of the image. For all lenses, the further away the projector is from the screen, the bigger the image becomes.
Ideal throw distance is calculated thus:
Throw distance = throw ratio × image size(width)
Throw ratio is a projector specification that gives the ratio of distance to image size for that projector.
The width of the image depends on your projector screen. The image should be equal to the width of your screen (given in cm).
Telephoto (long-throw) projectors need a long distance to get a large image while Wide-angle (short-throw) projectors throw large images from short distances.
Zoom-enabled projectors can vary their throw ratios and ultimately, their throw distances.
Projector Zoom Lens
A zoom lens can adjust its focal length to enlarge or reduce an image on the screen. You do not have to move the projector backward.
The projector zoom lens allows for two things:
- You can mount your projector over a range of distances and still get a given image size.
- You can project a wide range of image sizes from a fixed projector mounting position.
The throw distance dictates your projector placement, but you can vary the projection distance for fixed screen sizes with a zoom lens.
The zoom lens of your projector can be used in either ‘Wide’ or ‘Tele.’ In the following sections, we’ll explain these terms.
What is Wide?
Click image for more info
The Wide mode on the zoom lens — also called wide-zoom — covers an angle of view between 64° to 84°. Ultra-wide zoom can cover up to 180°.
In this mode, the lens focal length is between 24 – 35mm which is shorter than that of a normal lens.
Wide-zoom allows the image on the screen to become much larger and to have an expanded horizontal scope.
Short-throw projectors come with a wide-angle lens. They project large pictures from short distances.
The advantage of using wide-zoom on your projector is that you can shorten the throw distance and still maintain a large-size image.
What is Tele?
In Tele mode, the focal length of your zoom lens becomes longer than that of standard lenses.
The focal length of telephoto lenses ranges from 85mm to 600mm, causing the projected image to be narrow.
It is important to note that long focal length improves contrast. How?
The light coming from the lens is concentrated at a narrow angle between 29° – 4°. This maintains the sharpness of the image.
Tele-zoom maximizes projection distance. Due to the narrow image, you need a long throw distance to get a large image.
Long-throw projectors make use of fixed telephoto lenses. They are only capable of creating large images from far distances.
Comparison of Projector Distances: Wide Vs. Tele
short throw vs long throw projector
We have put together a comparison that will help you decide on the best projector distance for you.
It would help you decide whether to use a short-throw (wide-angle) projector, a long-throw (telephoto) projector, or a zoom projector in Wide or Tele mode.
A telephoto lens maximizes projector throw distance, while a wide-angle lens minimizes throw distance.
Which one is better? Let’s get right to it.
1. How They Work
The focal length determines the angle of projection of a lens.
A long focal length results in a narrow-angle, little magnification, and a smaller image. This is why telephoto projectors need a long throw distance to increase their image size.
On the other hand, a short focal length results in a wider angle, higher magnification, and a large image.
Wide-angle projectors project large images. Hence, they don’t need to be placed far from the projection screen.
2. When to Use
If you have sufficient room space, we recommend Tele-zoom or telephoto projectors.
They maximize the projection distance and allow you to sit far away from your projector.
If you have a small space, or prefer a closer mounting distance to the projector, a wide-angle lens minimizes the throw distance.
A shorter distance between screen and projector can prevent viewers from casting shadows on the screen.
3. Distorting Effect
At extremely long or short focal lengths, projector lenses may experience some image distortion.
Telephoto lenses, because of their narrow-angle of projection, make distant objects seem closer and more life-sized.
Wide-angle lenses on the other hand make the perspective look exaggerated; closer objects look bigger and distant objects look even smaller.
This effect amplifies the distance between objects and makes them look further away from each other than they truly are.
4. Brightness
You will notice a difference in brightness if you use a zoom projector because its lens allows flexible placement.
In wide-zoom mode or with a wide-angle projector, you get the largest image from a short distance.
The beam from the projector lens doesn’t have to travel far before hitting the screen. There is little interference from ambient light.
With Tele-zoom or a telephoto projector, the projector has to be far from the screen. The distance allows ambient light interference and reduces brightness.
5. Cost
Long-throw projectors are generally cheaper than their short-throw counterparts.
This is because the quality of glass required to make a telephoto lens costs less than that for a wide-angle lens.
Zoom lenses can alternate between the two modes. They require a complicated assembly process, and they ultimately cost more.
Our Recount
If you have enough room, it is better to use Tele and project from a long distance.
Projectors can be noisy, so it is more convenient to place them far behind your sitting position.
The image leaving the telephoto lens is narrow. This is an advantage because smaller images work better with anamorphic lenses — there is very little barrel distortion.
Tele-zoom images are sharper, and telephoto projectors are relatively less expensive.
Wide-angle projection also has certain advantages, but the lenses are often expensive and run a higher risk of image distortion.
Wide-zoom or wide-angle lenses improve brightness. Due to the short distance, there is less refraction of light.
Wide-angle projectors are recommended for small rooms.
FAQ
How far away does a projector need to be for a 100-inch screen?
The projection distance depends on the throw ratio of the projector and the width of the image or screen.
Throw ratio is listed among device specifications. Standard projectors have a throw ratio of about 2:1 while short-throw projectors are between 1.4:1 to 0.3:1.
The ideal projection distance can be calculated using the formula below:
Throw distance = throw ratio × image size (width)
According to Screen Size Calculator, a 16:9 screen with a diagonal of 100″ has a width of 87.2″.
Standard throw ratio = 2
Throw distance = 2 × 87.2″
= 174.4″
The ideal distance to place your projector would be 174.4″ away from the projector screen.
Conclusion
Wide and Tele projector distances each have their perks. However, you must choose wisely.
The better option between a wide-angle lens and a telephoto lens depends on the amount of space available in your room or home.
Ultimately you can get a zoom projector and lengthen or shorten the projection distance as you please.
Vance is a dad, former software engineer, and tech lover. Knowing how a computer works becomes handy when he builds Pointer Clicker. His quest is to make tech more accessible for non-techie users. When not working with his team, you can find him caring for his son and gaming.