Viewing Angle

[howdous]

If the audience is sitting inside a theatre with different height levels of seating, how would one then deal with the projection angle? Would audience members at a certain seating height have a better viewing experience than others? If so, how would one deal with it?

[Robin D]

There are I believe two questions here. Projection angle is the angle from which you project onto the screen. That can be anything that the projector will deal with and still provide a correctly proportioned image.

 

Viewing angle is the view any particular audience member will get and every seat will have a different view. Your image needs to be far enough away and large enough to allow all four corner seats of the auditorium to view it. If a restricted view, you would need to sell seats based on that arrangement.

 

Large auditoriums may use multiple screens to solve the viewing angle issues, but to be fair, its usually the width of the seating that creates the issue, rather than the height. In my experience. the worst view is often the extreme ends of the front row that have to look left or right at quite an angle, and often look up as well and are much nearer the screen. That can be quite uncomfortable.

 

Hope I've correctly identified the real question you were asking.

[timsabre]

I was wondering if they were asking about using a projection screen with gain, where the screen is semi-reflective and has a limited viewing angle.

If that was the question, then unless the audience is very close to the screen they would normally all be within the viewing angle of a typical screen unless it is very high gain.

 

Perhaps the original poster could explain a bit more what they are trying to do as the question did not have much information to go on.

 

 

[Robin D]

Good point Tim.?

[Just Some Bloke]

Just to widen the discussion further, don't forget that if you use a large screen that is fairly close to the audience, then the first few rows may not be able to see all the picture at once. The human eye usually has around a 60 degree field of vision with the centre 30 degrees being in focus. If the screen needs more than 60 degrees for the front few rows then this can get quite annoying, even if the picture quality is good.

[bruce]

Avixa (formerly Infocomm) has lots of good guidelines and calculators for screen angles. You don’t have to be a member to get access, but you do need to register.

 

The AETM (Australian Education technology Managers group) has some good guidelines on design of teaching spaces, which reflect the Infocomm/Avixa guidelines.

https://www.aetm.org/av-design-guidelines/

 

These give guidelines for how big a screen needs to be to cover a given auditorium, for various different content types. But they also show how a screen can be "too big” for the closest viewer - you want a front row seat’s view to have a maximum “width” of 60 degrees, and the top of the image should be no more than 30 degrees above eye level.

[ninjadingle]

Following on from Bruce's reply...

 

Nearest viewer should be no closer than 1 x screen width (for 16:9 formats)

Furthest viewer should be no further than 4 / 6 / 8 x screen height (depending on content, 4 for detailed text eg spreadsheets, 6 for detailed graphics / casual text eg powerpoints, 8 for casual graphics / video eg film viewing)

OR furthest viewer should be no further than 150 x font size (if you can control the content. Usually impossible hence the rule above)

Closet viewer should look no higher than 15 deg up to bottom of screen, or 35 deg up to centre of screen

Viewers should be within a horizontal 90 deg cone, extending 45 deg either side of a perpendicular line drawn from screen centre.

 

Mostly possible, but with auditorium design there's always compromises to be made. The 90 deg cone usually gets forgotten about, but the 15/35 deg rule is quite important, else the closer viewers get neckache! Nearest distance rule is usually possible, maximum distance is dependant on room height and minimum screen height (another load of numbers).

[timsabre]

The original poster has not been back since they posted the question a week ago. I think we are talking to ourselves.

[howdous]

Apologies, been very busy on this project and only checked in now. I just want to thank everybody for their input, it was helpful indeed. It was the viewing angle I was after in terms of vertical angle (height) but I am glad you guys also mentioned the horizontal angle.

 

Next step is to source the correct projectors and I believe these are the people to speak to? - https://www.barco.com/

The original poster has not been back since they posted the question a week ago. I think we are talking to ourselves.

[ImagineerTom]

Since your project involves quite specialist projection surfaces (which have very specialist rigging/setup requirements) and large specialist projectors which have very particular needs when used with the projection surfaces you are projecting on to I really think the best advice anyone can give you is that you shouldn't be trying to coordinate this project in house and should instead be handing the technical side of this project to a company who've done this before; someone who knows all the technical problems and complications you are going to face and who has the expertise to avoid them and make the project seamless; all you have to do is tell them what you want to achieve.

 

By definition whoever you're planning to get the Hologauze from will be able to put you in touch with multiple companies with experience of doing exactly what you are trying to do; ask a couple of them for a quote and save yourself a lot of stress and hassle.

[howdous]

Thank you Tom, that is indeed how we are approaching this.

Since your project involves quite specialist projection surfaces (which have very specialist rigging/setup requirements) and large specialist projectors which have very particular needs when used with the projection surfaces you are projecting on to I really think the best advice anyone can give you is that you shouldn't be trying to coordinate this project in house and should instead be handing the technical side of this project to a company who've done this before; someone who knows all the technical problems and complications you are going to face and who has the expertise to avoid them and make the project seamless; all you have to do is tell them what you want to achieve.

 

By definition whoever you're planning to get the Hologauze from will be able to put you in touch with multiple companies with experience of doing exactly what you are trying to do; ask a couple of them for a quote and save yourself a lot of stress and hassle.