hmm sort of novice myself but what are the exact measurements of your room?

my room is 13x19x10 and my first row is about 10' from a 123" screen 16:9 screen. its fine for movies but they complain when gaming due to eye movement. just because you can doesnt mean you should.

also i only run a epson 5030 1080p projector and from my readings newer 4k content/HDR/10+ and all that fancy stuff needs more lumens getting to the screen so going big needs a very good projector.

so you really need to determine your seating distance, your content, budget and where the pj will be mounted/distance from screen. also the screen itself is important as if say acoustically transparent it may not have enough "gain" for the distance form pj to screen/pj lumen out put.

i am sure more educated will post soon.

 

hmm sort of novice myself but what are the exact measurements of your room?

my room is 13x19x10 and my first row is about 10' from a 123" screen 16:9 screen. its fine for movies but they complain when gaming due to eye movement. just because you can doesnt mean you should.

also i only run a epson 5030 1080p projector and from my readings newer 4k content/HDR/10+ and all that fancy stuff needs more lumens getting to the screen so going big needs a very good projector.

so you really need to determine your seating distance, your content, budget and where the pj will be mounted/distance from screen. also the screen itself is important as if say acoustically transparent it may not have enough "gain" for the distance form pj to screen/pj lumen out put.

i am sure more educated will post soon.

Thanks for the response. I don't have the exact measurements because we haven't moved in yet but seeing the theatre when I made an offer on the house I know it's big. I base my max screen size on the idea that if eye level is 44" from floor and screen is placed with eye level at 1/3 from bottom screen can be up to 270". Theatre would be just for movies. I'm looking to spend about 2k on the projector and can ceiling mount it wherever it needs to be based on throw. I have no preference on how far back I want to sit.

 

People often think of screen size as a function of viewing distance (sometimes you sit 1.2x your screen size so you might sit 12 feet away from a 120" screen). So ideally you choose where you want to sit and go from there.

Also, wall size isn't the only limiter for screen size. Projectors have throw distance which may limit your screen size based on which protector you get and where you mount it.

 

Thanks for the response. I have no preference on how far back to sit and the room is long so I would base my seating position on whatever the best screen size is. I'm leaning towards an epson 3800 but can ceiling mount it wherever I want to get the ideal screen size. The room itself doesn't have many limitations so it's mostly dependant on how to get the best picture quality.

 

Good advice so far. This is an interesting question because I was thinking about this as I was driving into work this morning. I've already had my projector set up for many years. Another forum user was asking similar questions.

There's a whole bunch of parameters that interact with each other. So if you change one, it affects the other. For instance if you change your viewing distance, that may affect the size of the screen. But in my opinion, it goes something like this:

1. Since you have a room, find a wall and find your seating area. Now measure the viewing distance from your eyes to where the screen is going to be.

2. Now that you have the viewing distance, an important parameter is called the field of view. SMPTE and THX both have recommendations. See this link for a field of view calculator. THX recommends about 36° to 40°. For my room I chose 40°. You can try this calculator to punch in some numbers such as your viewing distance, and then you can select a diagonal of a 16x9 screen and you could play around with the diagonal value in order to get a 40 degree viewing angle.

Viewing Distance Calculator

Viewing Distance Calculator

myhometheater.homestead.com

3. Great so far. You know how large your screen is. And you have the viewing distance. The next critical factor is brightness. SMPTE has a recommendation for movie theater brightness. It is measured in foot lambers. The standard is 16-ft Lambert's. You get to foot Lambert's by taking the lumen output of your projector and dividing it by the square feet of your projected image on the screen. Using the diagonal screen size from step number two, you can compute your square footage of your screen. As an example, my screen is 135 in 16x9. You can try this screen calculator, put in the diagonal, and then click the calculate button to compute the width and height. If you're using inches, multiply the height and the width and divide by 144. My screen, I get 54.1 sq ft.

Screen Size Calculator

This calculator helps converting the size and dimension of a screen (in cm and inches) into each other.

screen-size.info

So in my case, I get 54.1 ft * 16 ft Lambert's = 865 lumens

4. Now you have to account for aging of a bulb, which generally ages 50% as you know. So you may need a projector, if you were in my case, 1700 lumens just to have the bulb in by 50% so you can get your 865 lumens that you need for 16 ft Lambert's. Unless you go laser projector which is a different ball game because you don't get the dimming that you do with the bulb.

5. There's a whole bunch of parameters that affect the calculations that we did above. It's just the first run through in order to size your screen based on your viewing distance. The calculations are pretty standard for 16x9 screen.

I hope that was helpful.

-T

 

I replied above, but I wanted to chime in about the 270-in screen that you mentioned. You'll never be able to have a 270 inch screen. The amount of light that you would need for that from the projector would be unbelievably high and awfully very expensive.

-T

 

Thanks for all the info. 270 being unfeasible was my assumption but I couldn't find any good info to determine what the screen size limits would be for a projector in my budget. I played around with some of those calculators and they are definitely useful. Math is not my forte. Using an epson 3800 for example, at what screen size would the picture quality deteriorate? It's hard to calculate brightness because the manufacturer listed max lumens but they would not be the output with proper settings for movie watching.

 

First off our definition of "LIGHT CONTROLLED" is not only a room that is pitch dark with the lights out but also non reflective walls and ceiling ie no white ceiling. The projector it self is a large light source so if the room is reflective the projectors light reflecting off surfaces will washout the image. Now when it comes to screen size it is purely personal preference and no one can tell you what your going to prefer so experimenting with a projector is your best option. It is true anything over 200" in a "light controlled" room really needs a large venue projector with 5000+ lumens to be effective. Non light controlled rooms thing go south in a hurry. There are large venue projectors refurbed or used in your price range but they are designed for board rooms, churches and auditoriums and are fairly poor at contrast especially. I wouldn't go over 200" with the Epson 3800 if the room is light controlled.

 

Good point about the personal preferences. We can do calculations all day long.

Before I built my first screen in 2004 I settled on a 110 inch 16x9... Based on calculations to get me in the ballpark but I even put tape on the wall to though "yeah this looks good at this distance...I like this."

The reality was after I built it, I really needed to go a larger as I started to watch more scope material. So I eventually moved up to 135 16x9 Just goes to show us... Calculations get us in the ballpark but it really does come down to preferences and experimentation.

-T

 

A lot of people end up being constrained by their room's height. Not width. If a person is going to have multiple rows, the ability to see the bottom of the screen from the back row (over the heads of people in the front row) limits how large the screen can get.

Also, you don't want a screen so big that you have to constantly scan from side to side just to see what is happening. My screen (120") is the biggest I can go (based on my current 11 feet to the front row) and comfortably keep from getting motion sickness.

 

Agreed on the "scanning" point. One small qualification to that, though: When I built my first projector setup, my 120" screen seemed absolutely HUGE and I found myself struggling to take it all in. However, I eventually acclimated to it and after the first few weeks the feeling of having too much in my visual field completely went away. Now, that could be 100% unique to me, so take it with a grain of salt. Just something to keep in mind in case you find yourself on the edge with a particular screen size - especially if this is your first extended foray into projectors. Maybe give it a bit of time for your eyes/brain to adjust.

 

So projector central's review of the epson 3800 rates the lumens with cinema setting on high power mode at 1,623. Considering variations in each projector, brightness lost over time and other factors I used a conservative estimate of 1,200 lumens for my calculations. Better to have more than anticipated than less. With silver ticket's 1.1 gain screen, 165 inches would give me 16.35 foot lamberts, which I understand to be great for a dark room and a screen any larger would be too dim. Does this sound right? Since I am new to this I'm not sure if I'm missing something and need some reassurance. Thanks!

 

Two ways to approach it...

You can pick a projector first based on its capabilities with regards to picture quality and then size a screen based on that particular projectors lumen capability for maximum screen size.

The alternative is to pick a screen size and then look for a projector that can/will work with that screen size.

Maximum available contrast ratio achievable is typically the mitigating factor.

A balance between maximum lumen capability and contrast ratio will drive the price point.

High contrast ratio and high lumen output for a larger screen will typically cost you more.

 

I went back and re-read the review. He said he's got a 90 inch screen (16x9 I am assuming). Used natural mode for sdr. After calibration it was 24 ft Lambert's which comes to 576 lumens. That's a factor of 2.8 less than the lumency posted in the chart.

The reviewer goes on to say that the HDR calibrated lumens was 57 ft Lambert's in eco mode bulb. 78 ft Lambert's on medium. 86 ft Lambert's on high. That comes to 1368, 1872, and 2064 lumens, respectively.

So based on the information I posted above that I extracted from the review, I think the best case you can hope for out of the box is those lumens. So I don't know where the 1200 came from that you posted.

So if it was me looking at this projector, and knowing that bulbs reduce 50% over a certain period of time generally speaking, they may not dim 50% after all), I would try to research what that period of time is. Is it 1000 hours, 2000 hours, 500 hours? That would at least give you a basis of understanding how many lumens you'll have for the long term.

And then of course that drives your screen size.

One thing I did notice, and if you don't mind me saying, there's no powered zoom, focus, lens shift.. Those controls are manual. You might want to think long and hard about that. Look at you use cases now and in the future and determine if you think you're going to need those three items, or some subset, powered.

-T

 

Thanks for taking the time to look in that, T-Bone. I used 1,200 as the lowest estimate assuming the projector I get is dimmer out of the box than the reviewer's and it loses brightness over time. Also, my settings may be different than his.

I have read about the powered functions you reference but due to my lack of familiarity with projectors, I have not been able to determine how that would affect me. My understanding is that the projector is natively 16x9 which means I should use a 16x9 screen. I assume the zoom, focus and lens shift would not need to be adjusted again after the initial setup. Even if the movies I watch are in different aspect ratios, it would just fill the empty areas with black bars. Is this incorrect and I would have to change the zoom, focus and lens shift depending on what I'm watching? How would the powered components benefit me?