CurtPalme.com Home Theater Forum

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

THX has a 40degree recommendation or ratio of 1.37 - so for a seating distance of 8' (96") the screen width would be only 70"

that seems small, and i've been told here that it is small.

what is the screen width to seating distance ratio in your theater? if you have multiple rows, then what is it in your favourite seat?

cheerLance

ecrabb · Posted: Tue Jan 11, 2011 10:13 pm Post subject:

Lance, the 40-degrees specification has to do with digital displays and seeing pixels. If the viewing angle gets much larger than 40-degrees, the chances of seeing pixels or screen door starts to shoot up for people with normal vision. At 50-degrees, a lot of people might see pixels even on a 1080p display.

For commercial cinema on the other hand, the 36-degree viewing angle is a minimum. In other words, the worst seat in the house should, at the minimum, have a 36-degree viewing angle.

If you think about it, many commercial cinemas' front rows are less than 20 feet from a 30-40-foot wide screen, so viewing angles approach or exceed 90 degrees, while the vast majority of the rest of the seats in the house all have viewing angles that far exceed 40-degrees!

I like a (visually) large screen and immersive image, so I sit 9-10 feet from my 8-foot wide screen (depending on whether I'm reclining or not), so 43-48 degree viewing angle for my seat. I LOVE IT. I love the immersion... I'm involved in the picture. That's what cinema, and by extension home theater, is all about, right? A big screen! The whole "tennis match" thing is totally over-rated, IMHO.

My back row is about six feet further back, or 15-16 feet, or about 28-30 degrees viewing angle. It still looks fine, but it's much less involving, and I would hate that kind of viewing angle for my main viewing position. You need a pretty big room and pretty big screen to start to accommodate THX specs for multiple rows in a home theater.

Cheers,
SC

LOTREE · Posted: Wed Jan 12, 2011 2:23 am Post subject:

In the theatre, aka livingroom, I sit at 10.5'/126" only because I'm limited by space, things can't physically get farther apart. As a result I'm throwing a 7'(84") wide/8'(96") diag image. I think it's perfect, I don't like being closer.

So, my ratio is 1.31-1.5 depending on the screen measurement you use.

Now, that being said my father's theatre with the 9500LC has an 8' wide screen and I personally like the picture WAY better sitting in the back raised row about 16' from the screen. I feel like I'm in a theatre, with a black tunnel and big screen in the end. I don't like the screen in my face, too much light, too much going on and hard to get it all in. The same reason I don't sit near the front in an actual theatre. Always, when I can, sit 3/4 way up dead center.

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

when i'm in a commercial theater, i usually sit so that the screen size is "pinky finger to pinky finger plus a palm" thumbs touching, fingers splayed at arms length. pretty consistent. that comes out biger that the THX. about 1.1:1 or so.

realizing (thanks SC) that the THX 1.40:1 is meant to be the *worst* that you'll have explains a lot. i bet that at the back of the theater that's what you get.

ecrabb · Posted: Wed Jan 12, 2011 3:45 am Post subject:

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

my wife has figured out my "stretching" that i do whenever we sit down in a theater. and here i thought i was being subtle.

Very Happy

**AnalogRocks** · Posted: Wed Jan 12, 2011 4:32 am Post subject:

Front row center!

WanMan · Joined: 19 Mar 2006 Posts: 10273

I prefer to sit where the hell I want to in my theater. THX be damned. If it coincides, cool. If it doesn't, I'm not losing sleep over it. As long as I can personally determine the threshold at which I can see pixel structure then I know where I'll be comfortable at.

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

well yeah, i'm going to where i want Smile

i was just curious why the THX std seemed so small.

ecrabb · Posted: Wed Jan 12, 2011 8:06 pm Post subject:

WanMan · Joined: 19 Mar 2006 Posts: 10273

Sitting 13' back. The 10' screen in 2.4 aspect (37.6º) and 7.4' screen in 1.78 (29.7º). It was funny when a friend of the wife revealed she has motion sickness issues and I happen to put in I, robot for the demo. Oops Very Happy

dturco · Posted: Thu Jan 13, 2011 12:48 am Post subject:

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

[quote="dturco"]