What size screen do I need for home theater to project both 4:3 and 16:9 ratio pictures. Large as poss.?

Answer 1

Its hard to say without knowing the brand and model of projector. Canon has a awsome "throw distance calculator" on the site. Try http://www.usa.canon.com/consumer/controller?act=ProductCatIndexAct&fcategoryid=109
this a flash based "program" so you must have a flash player. Keep in mind you need a 16:9 or rectangle screen to project anamorphic movies really large. The 4:3 is easy, you will just have negative space on the sides.

Answer 2

I faced exactly your question when I was planning my home theatre. I'll tell you how I answered it, and why, and you can translate to your situation. It turns out to be more complex than you might think.

Initially I wanted the largest screen I could get in the room. I was thinking in terms of a 120" screen or larger. But I eventually realized that it isn't size per se that you need to consider, but the optimum angle subtended by the left and right limits of the projected image, and what screen size this defines at the seating distance you plan to use.

Once I reaqlized that, the question became what is the optimum screen size if I want to view the screen at a distance of 10-11 ft? An important secondary question was what was the right screen shape (aspect ratio), and also what projector is going to be used.

The answer to the size question turned out to be smaller than I had originally thought. The link below takes you to a "Viewing Distance calculator" which is just as useful for determining screen size if you know the viewing distance.

Before using is let's also consider aspect ratio and why the projector also matters. Two earlier respondents assume projecting 4:3 images within the bounds of a 16:9 screen. I actually do the opposite. I project widescreen (1.78:1 >> 2.4:1) full width on a 4:3 screen chosen to have a width optimum for my seating distance of 10.5 ft. I then have black bars top and bottom for all but 4:3 material ... which comes out really huge. BUT, this is only really practical if the projector has a native 4:3 format and reasonably high resolution. In my case my projector is a SVGA+ (1400 x 1050) 4:3 projector which delivers a 16:9 image via a 1400 x 788 pixel subset (about 10% higher resolution than a "normal" 1280 x 720 HD projector). However, a native 1280x720 widescreen projector would generate a 960 x 720 4:3 image -- much lower resolution than the Canon's 1400 x 1050 image, suggesting that with a widescreen projector the right choice for screen may well be a 16:9 aspect ratio (and projecting 4:3 images as a subset -- i.e. fill top to bottom, with bars on the sides).

Sorry if the foregoing is hard to follow, but I thought it worth including since it is important for a complete picture. That said, let's go to the heart of your question.

In deciding on screen size it is important to realize that everyone is different re what they consider desirable. Think of a movie theatre: some viewers, given the choice, sit right at the back, other half way and a few right up front. Each sees an image that from side to side subtends different angles (possibly 15 degrees at the back of the theatre and maybe 45 degrees or more at the front), but most people prefer between about 26 and 36 degrees, with a minimum of 30 degrees being defined in the SMPTE standard (EG-18-1994). On the other hand THX recommends 36 degrees as the optimum.

So, using the distance calculator and a viewing distance of 10.5 feet I found that a 36 degree angle was defined by a screen with a 82" width (i.e. a 94" 16:9 screen or 103" 4:3 screen). I wanted a bit bigger, so I eventually chose a 110" 4:3 screen, which equates to a 38.5 degree viewing angle. And I can say after a few months that this is about as big as I would want. In fact I have used the lens zoom to shrink the image down a bit on occasion. I have had no wish to increase the size.

So long answer (sorry), but you should now be able to calculate the right screen size (and aspect ratio) for your room, seating and projector, considering your preferences based on where you like to sit in a theatre. Of couse, if you intend to have others watch too, you may want to take their views into account before departing too much from a screen width outside a 30-38 degree viewing angle.

Hope this helps.

Answer 3

Easy, Simple ratios, any 16:9 screen will do.. since the height does not change, only the width changes... the 4:3 will have black bars on each side on the 16:9 screen but will be completely filled with HDTV(16:9) programing.

I have a projector and a 52" x 92" da-lite screen (16:9 ratio) HDTV fills the height of 52" and width of 92", when I watch regular TV it fills the height of 52" and goes to 70" wide.

Have Fun!