It is a misconception that the distance of the projector from the screen effects the brightness levels. However, now that you have your [ANSI Lumen] brightness level estimated, distance must be considered to select the correct lens on your projector.
Many professional projectors have lens options to hire or buy. Some lenses have zoom functions that will cover a range of distances. Some lenses (particularly wide lenses) are fixed.
Projector lenses all have different ‘throw ratios’ – the width of the image/screen relative to the throw distance.
Again, there is a simple sum you can use to gauge the correct lens:
projector throw distance = Lens ratio
width of projected image
Alternatively, should you be considering a projector and want to know that the lens will be suited at the correct distance:
lens ratio x width of projected image = projector throw distance
Here is an example of those sums at work:
You have a screen that is 8m wide and you know that your projector will be placed around 15 meters away; you need to calculate the correct lens, so:
15 [projector distance]/8 [width of screen]= 1.875 – Accordingly, search for a 1.87 lens ratio.
Using the Panasonic RZ21K as an example again, this would mean using lens ET-D75LE20, a 1.7-2.4:1 zoom lens.
5. Plot in advance
No one has as much experience of creating content suitable for Hologauze®, or working on installation jobs across the world as Holotronica.
We offer a pre-visualisation service: we can plot your space, trying out various projectors and throws within a virtual 3D mock-up, which means a seamless set-up for on your event day.
Want to discuss your project requirements?
Contact Holotronica for all your holographic needs.