Chart Distance x Screen Size - Standards SMPTE and THX - Page 2

Peter,

Thanks for all the great information. You need to convince the moderators to make this a sticky thread.

Cheers,
Scott

These charts and tables for good starting points, but viewing distance is a very personal thing, with wide variation in preferences. E.g., with a 2.35 screen I have seen many people report liking to sit ~ 1 screen width away ((53 deg viewing angle). This is a bit too close for me; I sit ~ 12.5 ft from a 12 ft W 2.35 pic (51 deg angle). For a 16x9 pic, from this same viewing distance, my viewing angle is 46 deg, which I fine good. I.e., I like a very immersive pic, but others fine it better with smaller viewing angles.

And I agree with Darin, that viewing angle [2*arctan(.5/SW), where SW is the viewing distance divided by the screen width] is the more useful parameter to discuss.

yeah it helped me too.

i am wondering which standard i shall go with? THX or SMPTE?

i got 100inches 1.3 gain screen. i have to shrink it a little bit ( 92inches). i sit about 11 ft from the screen right now. i hope that is okay.

Bump with new info:
I was posting in this thread, Will I See Pixels? , and saw new chart with 4k added to Carlton Bale website.
Saw it was not in this thread, the "old" 1440p was posted, so posted here as well.
Edited by mtbdudex - 10/13/12 at 9:59am

I try to point people to the info/data so they can grasp the "why things are they way they are" and reach their own conclusions instead of just telling them.
Your thread is a perfect example of that, give info and let them grasp.

Side note1;for those who took thermodynamics, remember your charts/tables used to explain the state of matter? (solid-liquid-gas)

and Pressure vs volume (lines of constant temp) ......or Temp vs Volume?(lines of constant pressure)


Now those took a while to use proficiently.....

Side note2: What is the only element that crystallizes from the top > down?
And why is that so important?

I promise this will be my only OT post here.....
Where are all the engineering geeks?
For sure I would have thought someone would have posted by now
H20
Ice rinks would not be possible, nor would life be able to sustain in ponds/lakes in the winter.

H20 is the only element that as it drops in temperature and nears it's phase change gets less dense.......so cold water only falls until 39deg f or so, then it rises and at 32deg crystalizes and then floats on top of its liquid self.
All other compounds don't do that.
Ask any mold engineer what the shrinkage rate it for something when it changes phase, and thy have to take that into account.

If H20 did not do that, then ponds would freeze from the bottom up and all life in it would cease to have a place to exist.
Don't you think that is kinda neat...who engineered it to be so?
Of all the compounds only water does that, why?

I got to the party too late. While I am not an engineer, ice seemed the logical choice.

These are very useful charts. Does anyone know what will be the difference with JVC X55 eshift on seating distance ?

I hope this helps. I am into CIH (Constant Image Height) and created this really easy to use diagram in Sketch Up. This is based on that chart that Gary posted on page 1 and is how I work out screen sized and seating distances.

The two images are the same, I have just scaled the 2nd up to 2x the size keeping the girl at 1:1 for a scale reference.

Both take the room length and divide that by 4 to find an ideal screen height. This was actually the recommended method back by CEDIA in the 1.33:1 days and works perfectly well today.
.
The screen height is then used for both finding the width (by multipling by what AR you desire) and the seating distances. In the chart posted by Gary, there is a minimum of 2x the image height recommendation by SMPTE. This can also be found on the Disney WOW Blu-ray and in real life experience (from someone that actually sits at this distance in their own cinema), it is very immersive.

There has been discussion about the THX 36 degree recommendation as well. Based on the chart posted by Gary, 36 degrees is about 3.68x the image height (for CinemaScope 2.39:1) and I have used that to find the farthest distance from the screen. Note it leaves a gap between the back seats and the back wall.

To keep it really simple, divide your room by 4 to find the image height. You sit NO closer than 2x and NO farther than 3.68x and you can feel free to sit ANYWHERE in between you want.

I have used the mid point between 2x and 3.68x to find the centre of the surround field. I have used equal spacing of 60 degrees between each surround. Even if seated behind the side LS/RS, you will still get good envelopment from a 7.1 system because you are still in the sound field.
Edited by CAVX - 3/4/13 at 2:22pm