InfoComm Survival Guide- Know These 3 Deceiving Specs
It is May 2022 and we are about 1 month away from #Infocomm22 in Las Vegas.
I’m excited to see the show back in a big way, and I know there is a lot of pent up excitement for a return to glory.
With that, there will be a lot of manufacturers on the floor who will also be excited to tell you about their products. You’ll be hearing a lot of buzzwords supported by speeds and feeds, and sometimes it’s hard to filter through the noise to figure out what is really relevant.
Many times specifications are seen as objective measurements, but just because something has a numeric value, it doesn’t mean that real world performance isn’t subjective.
With that, here are three specifications you’ll see on video products that are deceiving if you don’t understand them enough.
Pop Quiz! Which screen has smaller pixels?
- A 42″ Full HD screen (1920x1080p)
- An 84″ 4K UHD screen (3840 x 2160p)
Most people would think that a 4K screen would always have smaller pixels than an HD screen, but the truth is, in the examples above, both of these screens have pixels that are exactly the same size.
That’s because more resolution doesn’t automatically mean smaller pixels. The resolution or total number of pixels needs to be spread out over the screen area to get what really matters- pixel density or pixels/m2.
Don’t be fooled by more is better. More pixels may just mean more pixels, but depending on the screen size more could either be completely irrelevant or it could still not be enough.
If you want to dive deeper into this, I have a whole blog on it here.
Projectors usually list their brightness in ANSI lumens and many people use brightness as a way to specify a projector only to find later that the imagery isn’t great once the product is installed. Why is this?
First, brightness on its own means nothing. Just as with pixels in the resolution example above, that light needs to be distributed across the screen area to get brightness/m2 or LUX.
Second, brightness is measured at full white for the ANSI specification, but different technologies may produce different ranges of color brightness. 5000 lumen single chip DLP, 3-Chip DLP, and LCD projectors will all produce the same brightness of white, but there will be a marked difference in the brightness of Red, Blue, and Green in these three projectors. Understanding the differences can make a huge impact on your image.
Third, some projector manufacturers list center lumens not ANSI lumens. Be careful as center lumens will be a higher number. ANSI averages brightness from 9 screen areas. However, even the ANSI spec can be misleading as ANSI allows for variance in a products performance. Last I checked that number was at least 10%, meaning an ANSI rated 10,000 lumen projector can perform at 9,000 lumens and still be within its ANSI certification.
Finally, if your projector has interchangeable lenses, each lens has a different “light loss” factor. Depending on the lens, you could lose 5-30% of the brightness, and some lenses require the projector to run at a reduced output as to not damage the electronics and optics in the lens.
Imagine you pick a 10,000 lumen projector rated for center lumens. It really is rated at 9,000 ANSI lumens. Then due to acceptable variance, it actually produces 10% less or 8100 lumens. Finally, the lens you need to use for the proper throw ratio decreases that another 20%. Your 10,000 lumen projector is now delivering 6,500 lumens and that’s only in white. Your color brightness could be even lower.
Now if the brightness issues of projectors weren’t confusing enough, here’s another (larger) problem. Projected image quality is much more dependent on contrast than they are brightness. Brightness is actually just a tool to achieve the right contrast ratio to have a vivid image.
Contrast is the difference between an image’s deepest black and it’s whitest white. Here’s the problem. You can’t project black. This means the brighter the room, the higher the black level.
Now you may be thinking that projectors have contrast ratios listed in their specs, and they do. But those numbers mean absolutely nothing, unless of course you’re projecting in a completely light free test environment.
The contrast ratio listed on the projector is determined by comparing the brightness to the black level of the projector in a dark room.
The problem is that your install isn’t happening in that room.
A popular LCD projector manufacturer lists their contrast ratio as 2,500,000:1. Now that’s impressive to say the least!
That projector is 6,000 lumens. Let’s project it on a 16′ x 9′ screen. That means we have to spread those 6000 lumens spread over 144 square feet, or roughly 42 lumens /sqft or 450 lux. Lighting in a very dim room is 10 lux. Even in this scenario, your effective contrast is 45:1. That’s actually decent for a projected image, but nowhere close to the contrast in “the spec”.’
My advice is to outright ignore specs on projectors with regards to contrast ratios unless your application is a “dark room” theater or visualization type project.
These are just 3 ways numbers can be deceiving if you don’t understand what they mean and how they vary from screen to screen and from test to real world environments.
If this post freaks you out a little bit, then good, but don’t be discouraged. The good news is, that with a little training and education, you can navigate all of these nuances and become extremely valuable in helping people achieve their desired results.
This is why in addition to the annual show, AVIXA also offers training at Infocomm as well as online throughout the year.
I can’t wait to see you all in Vegas!