Understanding Projector Throw Ratio – Projector To Screen Distance

Installing a projector for the first time can be tricky, be it at home or outside for a backyard movie night with friends. You’ll come across new terminologies like projector throw ratio and suggestions from acquaintances about how it is done.

At this point, some people might consider giving up or just outsourcing the task, but it does not have to be so complicated. We’re going to shed some light on the projector throw ratio, so you feel more comfortable with your setup.

What is Projector Throw Ratio?

In simple terms, the throw ratio is the relationship between the width of the projected image and the throw distance. Throw distance is the space between the lens of the projector and the projected image.

Larger and more expensive projectors accept different lenses, whereas cheaper projectors come equipped with permanent lenses that you cannot change. Note that some lenses are permanently fixed at a certain throw ratio, while you can adjust others to cover a wider range of throw ratios.

Throw ratio refers to the particular image size a projector can project from a distance. For example, if the throw ratio is 1.5, the throw distance would be 1.5 feet for two feet of image width projected. So smaller throw ratios enhance the width of the images projected from a closer throw distance.

Calculating Projector Throw Ratio 

The throw ratio is a simple formula that lets you calculate throw distance or image width, assuming you already know one of these measurements.

The standard formula for throw ratio is throw distance divided by the screen width or TR=TD/W. 

If the distance from the projector to the screen is 9.8 ft and the screen width is 6.56 ft, take the distance and divide it by the screen width. In this case, you get a throw ratio of 1.49. Based on this result, you would know the type of projector you need.

An ultra-short-throw projector is best when the throw ratio is below 0.40, but you will need a short-throw projector if the throw ratio is between 0.40 and 0.80. 

If the throw ratio surpasses 1.1, a long throw projector is an ideal choice. After calculating the throw ratio and image resolution, you could use a throw distance calculator to specify the actual projector to be used. 

There are three categories of throw ratio. To better understand these categories, we will look at long-throw projectors, short-throw projectors, and ultra-short-throw projectors.

Long Throw Projectors 

Long-throw projectors have throw ratios greater than 1.0 and project images with a width less than the distance between them and the projector. Place these projectors far from the projector screen, and they are mostly used in cinemas.

Using a long-throw projector is a huge advantage if you have a large home theater or a significant distance between the electrical source and the projection surface. It would be very handy in large halls.

Long-throw projectors are also better if foot traffic is close to the screen. 

This projector provides minimal image distortion when mounted on a not-so-even surface. However, since these projectors work from greater distances, they are prone to interference from objects or persons in their path.

Short Throw Projectors 

The throw ratio for this kind of projector is between 0.4 and 1.0. So, if the projector shifts one foot away from the projecting surface, the projected image’s width will increase around the range of 1.0 ft to 3.0 ft.

A short-throw projector projects large images from a close distance using good lenses or chips. There are advantages to these projectors, the biggest being that a short-throw projector saves space. 

There are also no shadows when someone stands up to leave with this type of projector. Because they can project from such short distances, you can use them to project from very close to or behind a screen, reducing the probability of people bumping into the projector. 

On the downside, these short throw models can get pretty hot due to their extra processing power. When this happens, internal fans cool the gadget, which causes noise. Plus, projecting to uneven surfaces often leads to image warping.

Ultra Short Throw Projectors

The throw ratio for this category is below 0.40, which is why ultra-short-throw projectors work well in small apartments. 

Ultra-short-throw projectors mount close to the projection surface and are ideal for large screen TVs. These projectors use mirrors and wide-angle lenses to project the images from very close proximity. They also use lasers, so they work effectively in bright spaces.

Final Thoughts

We hope we shed some light on the concept of projector throw ratio.

Understanding how throw ratio works is essential when deciding which projector suits a particular experience, whether for a movie night outdoors or a meeting in a closed office space. 

When computing the throw ratio, bear in mind the layout and size of the room and where you will mount the projector in relation to the screen or surface. Consider any possible limitations and your preferred projected image width.