I am building a CIH 2.35:1 dedicated HT room, light controlled and soundproofed.

I usually sit in the 5th room or so from the screen in the movie theatre. I estimate that is around 60-70 degree FOV.

My finished room dimension is 13' W x 16.5' L x 8' H.

I am installing a 127" 2.35:1 screen with anamorphic lens. This means my screen width ratio on the first row in full 2.35:1 is 0.8, giving me a 63 degree FOV.

Yes, I know about the THX and SMPTE recommendations. Yes, I am installing a 1080p LCoS (not LCD) projector (likely RS1 on ST130).

My question: I would LOVE to hear from people who like me love to be immersed, sit close, and have configured for much closer than the 36 degree recommendation. Any issues? Anything to watch out for? How important has your VP been? Any motion sickness? Am I crazy? :-)

The stats:

Screen First Row Second Row
AR Width Diag FOV SW FOV SW
2.35 126.9 137.9 63.3 0.8 40.1 1.37
1.78 96.0 110.1 50.0 1.1 30.8 1.81
1.33 72.0 90.0 38.5 1.4 23.4 2.42

I gotta tell ya that seems too big. I had a 102" width 2:35 screen and that seemed big. I do have two rows of seating though in the exact size theater.
How many rows are you having. It just seems like you won't be able to take in the whole movie.

JMHO

Scott

I gotta tell ya that seems too big.


2 rows. So that's one for "crazy", ok...

I like the IMAX experience, so I love sitting close. SDE is my only prob with 720 DLP. Making the LCOS jump myself sometime soon. Your setup sounds good to me. I sat <10' from a 133" screen and loved it (except the SDE of course)
Warren

Keep in mind that a Cinemascope screen width is 4/3 a HD screen width - which changes your seating ratio to something just on the edge of OK for 720P and fine for 1080P especially if anamorphic lens. SMPTE uses screen height ratios - 2x-4x range since theaters prefer constant height - but theaters will often stuff chairs down front for those who get their last! The oft quoted THX rule is for the last row. If you can pace off the cineplexes screen by getting there early - you can compare their ratios for your favoured seat. Don't get yourself thrown out by pimple faced security though! You will want to do an extended PJ test on the wall before you commit - as not everyone in your family likes to watch ping-pong matches....

Why don't you wait on ordering the screen and try it on a white wall or if your room is further along than a white wall, hang a couple of cheap bed sheets and test it yourself.
It's a lot cheaper to wait a week or two for a screen than make a Big, Wide, mistake(pun intended)

scott

Why don't you wait on ordering the screen and try it on a white wall or if your room is further along than a white wall, hang a couple of cheap bed sheets and test it yourself.


Actually that's a good suggestion. Projector arrives tomorrow, and I will do that.

What I have done previously as well was to use my designer's demo theater. I calculated the equivalent FOV distances for 70-50 degrees, then we marked off the floor. I put the chair at the various locations and watched a demo reel.

I found that if the cadence detection was not very good I was not able to watch, but with a good VP, it was amazing and not an issue. 72 degress was a bit much, 50 was too boring. 65 degress-ish seemed ideal and gave me the same "theatre" feeling.

So I have done one prototype, and will do another this week...

(electrical rough in done, drywall starting)

I am planning on doing something similar, around .9-1.0 seating distance to width (about 2x height). I have a PJ arriving later this week and planning on testing out the various distances before I commit to a screen. I would be interested in your experience, and I will pass mine on as well. I am more of a 1/3 of the way back theater sitter, but I really want a big a$$ screen in my HT (or at least what will be big relatiev to the size of my room 15x12x8)

I found that if the cadence detection was not very good I was not able to watch, but with a good VP, it was amazing and not an issue.


can you explain this, plz.
Does VP mean video processor? And what is meant by cadence, plz?

Scott

can you explain this, plz.
Does VP mean video processor? And what is meant by cadence, plz?


Yes, VP is a video processor.

When a 24 frame per second movie is transfered to a 30 frame per second medium like DVD, you have to figure out what to do with the mismatch in frame rates (http://en.wikipedia.org/wiki/Frame_rate). One process is 3:2 pulldown (http://en.wikipedia.org/wiki/3:2_pulldown#3:2_pulldown). When playing back DVDs, something in the video chain has to detect and unwind it (http://www.hqv.com/technology/index1/cadence_detection.cfm?CFID=12104894&CFTOKEN=70432537), e.g. the DVD player or the video processor. This is typically done by electronics that look at the frames and detect the "cadence" (or inline playback signature) of the various frame rate matching processes.

The issue for sitting really close is that if this is not done very well, you get judder (http://en.wikipedia.org/wiki/Judder#Telecine_judder), the jerky motion you see in your home theater but not a real theater. Personally, this makes me motion sick very quickly when sitting close (far away you don't notice it as much). So a high quality VP is essential.

I noticed this using a projector built in video processor versus an Algolith processor.

There is a lot of material about this available online.

Eric

The oft quoted THX rule is for the last row.

Thanks for highlighting that. I didn't realize that was the case. Its a very important point.

Eric

PS: Your posts in the color accuracy debates have been exceptional. I have learned a great deal from them. Thank you!