Distance/Screen SIze Formula?

I have seen several guidelines. The SMPTE (Society of Motion Picture and Television Engineers) suggests HT installations should have a 30-degree viewing angle, but that is based on horizontal width. THX recommends 36 degrees. At 12' viewing distance, 30 degrees suggests a screen size of 88" on the diagonal. At THX recommended levels, your only choice on flat panel displays would be the new Panasonic 103" (which requires "permission" from Panasonic - they send a team of people to your site to check whether you can order it; if they say yes, you can special order one (for $50k+)). I saw one about a week ago. It's beautiful, but I decided to pass :^).

Based on those suggestions, a 60" would not be "too big." This matches my experience. The viewing angle is probably "fine", and keep in mind that if you have normal (20/20) vision, newer full-HD screens will naturally mean that you can be "closer" to your screen than non-HD screens because of the fineness of the pixels.

most of the people on AVS forum seem to recommend the seating distance to be 1.5x the screen width (not diagonal I believe)..however I have read that people have elected distances as short as 1.1-1.2x sw.

maybe you should head to an AV store...move a chair front to back while viewing a large screen display and see what distance you feel most comfortable with.

60" will be fine. SMPTE recommends 88" - this, IMHO, is WAY too big. Stick with the 60" screen and you'll be quite happy..

-RW-

I feel that some of the new distance calculations especially THX is more marketing then common sense, sure you dont have to be far from the monitor to not see the pixels as in old technology, but some of the ratios would seem a bit too much screen for alot of veiwers, in the end I think they could be doing alot of folks a dis-service by aiming them at super huge displays and sitting pretty close to the picture.....they just want to sell the biggest display possible, not the RIGHT one. Going all out for a dedicated theater and enjoying its larger then life experience is one thing, but a housewife doesnt need or really want to be 6ft away from a 65in screen with Rosie O'donnell at 10am in the morning (not that there is anything wrong with that) :)

I think 60" at 12' will be like sitting in a bar watching casual TV. IIRC, the SMPTE and THX numbers (88.5" and 107.4" 16 X 9 diagonal for a 12' vieiwng distance) provide the viewing angle from near the rear of a theater. I think you want the diagonal size to be at least half the viewing distance, preferably a bit larger. At 12', I think the only practical solution is front projection, and that's not practical for casual viewing given the ambient light constraints. A more practical solution is to decrease viewing distance.

It's not obvious what THX has to do with marketing monitors, except in so far as THX certification of certain components might add value. And SMPTE? It would seem in the best interest of both organizations to keep you coming to a theater.

Visit myhometheater.homestead.com/viewdistancecalculator.html for viewing distance calculators and explanations.

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