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Topic: Input Lag on Conference Projectors
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Joined: Jan 26, 2022
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Hi,

I have a unique situation. I need to project a roughly 20 x 33in table area (The aspect ratio is not important) straight down from a projector about 4-5 ft above the table. The room will be likely well-lit. Another aspect I need is a projector with a +50 vertical offset to get the lens aligned with center of the image. This is a projection mapping related project where the projection will cover an object with an irregular surface.

The Epson Home Cinema 3800 seems like a quality choice that can fit my needs, but with the needed area being so small I feel like it is a costly solution. I am aware that conference room projectors like the NEC P452W or the Panasonic PT-FW300NTU do not have good image quality or as high resolution but the brightness and low cost is attractive.

My only concern is that I can’t find any information on how much input lag conference projectors typically have. I’m not using it for quick gaming but I do need the image to adjust somewhat quickly, less than 80 milliseconds would be ideal.

I’ve attached an image to hopefully explain some of the setups I am considering: A normal projector at a 11 degree angle with keystone adjustment, a hung projector with +50 offset, and a first-surface mirror bounce with the +50 offset pj, although I could use a normal one with keystone. I know that some options like the keystone or the mirror bounce would have negative effects on the image, but since most projectors can’t point down that seems that the only options.

So my main question is if the input lag on conference projectors is negligible as those are lower priced and fit the 50+ offset. In the case where a mirror and/or about 11 degrees of keystoning is needed, how bad could I expect the image to get. I appreciate any thoughts on what would best work for this situation. Thank you

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You aren't going to get any cheap quality projectors without offset. It's worth noting that the SUPER cheap projectors, like those on Amazon, may actually be somewhat useful as they often have their lens aligned to the dead center of the screen.

Understand, that I have no idea what your lighting conditions are, but a typical boardroom projector needs about 80 advertised lumens per square foot of screen space to achieve about a 10:1 contrast ratio under normal lighting. Your screen square footage is miniscule. It's FAR smaller than is typical for a projector.

I also assume that you would benefit from a setup which is using solid state lighting instead of lamp-based lighting which will require regular lamp replacements.

At the end of the day, the Epson 3200 is a nice fit, but you also need to check the manual to ensure that it can support being positioned vertically. MANY projectors don't support this due to the design of the lamps and the cooling flow. So, throw that into the mix. The mirror option is, by far, the best design choice for any lamp-based projector which may be used.

Your table size of only about 4 square feet means that 320 advertised lumens is plenty to light it up well. A proper table surface treatment to enhance the image may help and is worth playing with, but I would likely start with some 'cheap' models as they may be ideal overall.

Take a look at this video, and then buy a few models to test out. Lag time isn't tested, but you can test, return what isn't working, and go with a solution that may be ideal for not a lot of cash.

https://www.youtube.com/watch?v=RNRT1UYACw4&t=74s

Do be aware that your throw distance to screen size may be a constant issue as these cheap models do NOT have zoom. Cheap business projectors have very limited zoom. A short throw model will NOT work for sure. So, consider that you may have to play with some models to get your throw distance where you want it, and depending on your actual use case, you could get by with cheap, but may be forced to pay more due to your own specifications requiring it.
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