# Confused by lumens



## MatthewJay (Apr 15, 2015)

I have no experience with projectors but would like to set up a simple home theater in our basement. I'm having a hard time analyzing how many lumens we need because of the many factors that appear to play into that decision.

We have a below-ground basement with a few glass-block windows. The basement is dim in the daylight but bright enough to read by (you wouldn't want to do it for long). At night, the streetlights shine in just about enough to walk across the room without tripping over things. The windows could be covered by blackout material, but somehow I don't see it ever being pitch-black down there, especially during the daytime.

I was planning to project onto a DIY drywall screen (which may become the topic of another post).

We want approximately a ten-foot wide screen.

How do we go about calculating how many lumens to look for? It seems difficult to find anything under about 3000, which seems maybe a bit bright from what I've been reading so far.

Thanks for any advice,

Matthew


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## tonyvdb (Sep 5, 2007)

The manufacture specifications can be very misleading particularly for contrast and brightness. Many projectors when set up to produce the proper color and black levels drop to about half if not less than half lumen output. There are however plenty of great projectors in the $2000 range that would work fine in your space. Both Epson and Panasonic have some nice options.

Have you looked at Projector central and their calculator?
http://www.projectorcentral.com/projection-calculator-pro.cfm


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## littlejohn74 (Feb 11, 2014)

+1 to what Tony said.

High lumens is only really necessary if your viewing area has a lot of ambient light. eg, watching movies during the day with all the windows open. Or if you plan on projecting on to a really really big screen, which means your projector will most likely be quite a distance away.

If you have a dedicate HT room, a projector with 1000 lumens would be more than enough.

One thing to consider is, projector lamps tend to degrade fairly quickly. I've seen as much a 50% in 6 months. So getting a unit with high early life output could be advantageous down the track.


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## MatthewJay (Apr 15, 2015)

Perhaps I should have mentioned that we are, unfortunately, limited to around $350 for the projector. (I know you get what you pay for, but in our case we're going to have to make do with what we can get!)

Are lumens typically an adjustable feature? E.g., could we use less than the full capacity to begin with, then bump it up if performance degrades over time?


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## tonyvdb (Sep 5, 2007)

No, generally the lumens listed on the specifications are at its top end. Your likely going to have to look at used or get a multi media projector in that price range. The problem with multi media projectors in that price range is they dont usually have the resolution of home theater projectors and the black levels are very poor.


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## Yiannis1970 (Sep 2, 2012)

MatthewJay said:


> Are lumens typically an adjustable feature? E.g., could we use less than the full capacity to begin with, then bump it up if performance degrades over time?


Hello!

In lumens we measure the illuminance of the units, aka the amount of light coming from a source. As it concerns video projectors, manufacturers usually state the maximum efficiency of the units in terms of light output. Think lumens as the total horsepower of the cars. A car with, let's say, 200 HP can reach 250 km/h in a straight road line but that's not mean that it can maintain that speed in every course with corners and turns. Same thing goes here...the amount of 2000 lumens meaning that the projector in its brightest mode, with contrast control at max, can output this sort of light. Such information though is practically useless when it comes for HC use. In this field the most important thing to know is the real light output of the unit in HC conditions, in other words, how much is the effective light output to watch our movies in the screen according to various standards. Noone cinefile would prefer dynamic mode on his projector. So, the real question is: Are my projector's real lumens capable to fill my 100-120-150 inches screen?

So, yes, lumens are adjustable by using the various mode on your projector. Usually ''cinema mode'' produces the less bright image but well balanced in all sectors.


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## RTS100x5 (Sep 12, 2009)

MatthewJay said:


> Perhaps I should have mentioned that we are, unfortunately, limited to around $350 for the projector. (I know you get what you pay for, but in our case we're going to have to make do with what we can get!)
> 
> Are lumens typically an adjustable feature? E.g., could we use less than the full capacity to begin with, then bump it up if performance degrades over time?


In that price range , your talking about extreme entry level quality - not even 1080P that I could find on Amazon - unless you can spend more, then your choices are very limited...
The minimum I would suggest is something like this Optoma for 599 - at least you'll get 1080p, 3D and a descent lumen output....

http://www.amazon.com/Optoma-HD141X-Theater-Projector-Enabled/dp/B00MK39P92/ref=sr_1_2?s=electronics&ie=UTF8&qid=1430239221&sr=1-2&keywords=home+cinema


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