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It’s about time you get a crash course on projection blending! But seriously, even if you don’t care about projectors or want nothing to do with it – stick around. Because event planners do need to get educated on certain aspects of AV. At the end of the day, the success of your event is the sum of many things. And that includes AV and, you guessed it, projectors!

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So join our lovely host Will Curran while he walks you through the basics of projection blending. Maybe you’ll fall in love with it. Or maybe you’ll get inspired. Either way, you’ll learn something that can make your events better. And what event planner doesn’t want that? So press play and let’s get to this week’s edition of Whiteboard Wednesday!


projection blending The Basics of Projection Blending – Video Transcription

What’s going on everybody? Will Curran from Endless Events back here again with another Whiteboard Wednesday. And today we’re talking about the basics of projection blending. Well, that might sound confusing and technical. And, “I don’t want to listen to it. Oh my God, click out.” No, don’t do that now, even if you don’t know anything about projectors. I’m going to explain some basics that will help you understand this a little bit more.

Why You Need To Know About Projection Blending

This came after essentially this last week. I had a client who decided, “Hey, we’re not going to go with our backup projectors. We’re going to end up not doing double the amount of projectors. Because we had these nice 30 foot by 10-foot screen screens on either side, very awesome looking corporate setup.” And they ended up getting rid of that. And onsite they said, “Oh my gosh, it’s not bright enough. We wish it was brighter.” Obviously, as an AV company, we regret allowing them to do that. But obviously we’re going to listen to what our clients tell us to do to save money. We could talk about that all day.

What I thought it would be interesting though is, I think that there’s not a lot of education for planners. And for people in the events, just to make sure you understand a few basics when it comes to projection blending. And kind of how this works, and why it’s important when it comes to your AV setup.

Let’s Talk About Brightness

So before we dive into it about the different types of blending and some basics around it, I want to talk about this graph right here. And before you go, “Oh my gosh, graphs, math, get me out of here. Click out, click out, click out.” I want you to pause for a second and we’re going to talk a little bit about the idea of brightness not equaling the same thing as the lumen projectors on projectors.

So you may know this, the brightness that’s outputting from the projector is measured in lumens. You might hear something like a 10K projector, or an 18K, projector, 21K projector. Well, obviously if you subtract those, it tends to make the projector dimmer on there. So one thing to keep in mind though is that perceived brightness, what your eye perceives as bright, is not equal to the number of lumens projected in the brightness of that projector.

Understanding The Graph

In fact, you get this sort of graph here. We have light intensity up on the Y-axis. And then we have the perceived brightness over here on the X-axis. The important thing to know is that at some point, yes, you’re going to see, for example, if you go from a 1K, 1000 lumen projector to a 3000-lumen projector. You’re going to see a big bump in brightness, what you perceive as being bright. But then you go from a 3K to maybe a 5K, or a 6K, you’re doubling again. You might see only a bit, a little bit more of a return.

Well, once you start to get into that 18K, 21K, 30K lumen area, you start to see this diminishing law of return when it comes to brightness. And what you perceive as bright when it comes to projectors. So one thing to keep in mind is that even though you might say, “Hey, I’m going to throw a ton of projectors at this problem and make it brighter.” There is definitely a diminishing law of return. That’s where we might want to look if you need it to be brighter, it needs to be outdoors, you might want look at led screens, things like that.

Projection Blending: Double-Stacked Projector

So I want you to just kind of keep that in mind as we talk about putting projectors on top of each other to make them double as bright and things like that. There is this diminishing law of return when it comes to the brightness of projectors. So the first thing when it comes to projection blending is, it’s as easy as you think about it.

So, for example, in a blender, if you want to make a strawberry banana smoothie, you’re going to put in strawberries. You’re going to put in bananas and your going to hit the blend button and output this new concoction. Which is strawberry and bananas. It’s not necessarily just strawberry, it’s not just banana. So when it comes to blending projectors, the most common setup that we see is what we call a double-stacked projector.

Where It Fits Best

This is very, very common in corporate shows for a couple of reasons. And first has to do with brightness. So for example, let’s say instead of doing a 30K projector, maybe what you’re going to do is stack a 15K on top of another 15K projector on there. And so what you end up doing is you stack these projectors on top of each other.

Then what you end up doing is you project over onto the same spot. So what you’re going to end up doing is taking this, for example, this case, the green projector here, projecting over here. And the purple projector and they have the exact same image, the exact same look, and what you’re going to do is you’re going to move them directly on top of each other. Literally pixel by pixel, making sure they’re absolutely perfectly aligned with each other onto that screen on there.

So, in this case, you’d go from having one single projector to having a single blended image instead of having two different projectors. Hopefully, that’s making sense to you. Rather than again you take the two that you have that you layer on top of each other, you’re able to then come in and put it as one single image.

It looks beautiful, it looks fantastic. Well, the reason why you do this again is, maybe make it a little bit brighter. But there’s also a humongous benefit. A lot of times when we do these double-stack projectors, we’re also hanging them from the ceiling. This is known as rigging, or you might be hanging from the truss, for example. Again, rigging it, you get it up in the ceiling.

Worst Case Scenario…

Well, let’s say, for example, Murphy’s law. Which we know definitely exists in the events industry. Let’s say this top projector dies. We checked in, we made sure it was all good to go. For some reason, I don’t know, a power surge happens and it knocks out the projector. Boom, this one’s out. Well, at least you had the projector right below it, projecting the exact same image. It will lose brightness, but at least you’re consistently able to keep that image up, get you through maybe the general session.

Or maybe, for example, one of the speeches and then when everyone clears out of the room, “Okay, cool, we’ll go swap out the projector, figure out what happened.” Everything like that. The show can continue, but if you do one projector and it’s up in the ceiling and it dies, well there goes your projector. You’re not going to be doing anything about it.

So the cool thing about this, you get the ability to have a little bit brighter of a screen. But also you get the redundancy and backup as well. So then that way if anything goes wrong, you’re set and ready to go. Okay, so that’s the basics of projection blending right there.

Ultra-Wide Screens

Well, now we’re going to talk about a little bit more complex blending. And this has to do a lot of times with the ever so popular ultra-wide screens as we call them. For example, we have a crazy aspect ratio. So for example, you might have something like a 30 by 10-foot screen for example, or you might have a 40 by 10-foot screen. You might have a 500 foot by 30-foot screen. I don’t know what you want to do there.

There’s a lot of different choices when it comes to these super ultra-wide screens. When it comes to it, anything’s possible. Well, the same principle amount to explain applies to all of them, just centrally repeating over and over again. So when it comes to these triple wide screens, they’re super-duper popular. But I see a lot of planners and a lot of AV companies pitched this idea, but then execute it improperly.

The most common thing that I think that AV companies try to do to get this look, but while doing it on the cheap, is they take this 30 foot by 10-foot screen. And they think, “We’ll just push it back further and we’ll just use one projector to project on it, or I’m going to use one projector and then just blend it, so they’re just stacked on top of each other.” That’s not the way to do it.

Doing It Right

So what you’re going to want to do is to take this concept I’m about to explain. It’s getting a little bit technical but hang in there with me. So the first thing that we’re going to do here is we’re actually going to take two projectors instead of having them stacked on top of each other. We’re going to have them side by side with each other on here.

And normally if you think about it, you might, to get the coverage that you need. You might take two projectors and cover half the screen with one projector and the other half with the other projector, right? And then again, we might double these up and do the double-stack projector on here. So that way, again, you get the backup and double redundancy, all that sort of stuff.

But instead of just putting each projector perfectly side-by-side and aligning them perfectly with each other. And then going in there, if for example, there’s a bump in the truss or there’s a … I had a million different reasons why we don’t do this, but essentially, let’s say they separate just a little bit. Now you’ve got two separate images, you’ve got this one single image with maybe a border, and there’s a gap between,

Oh, it’s going to look so ugly. We don’t want to do that as an AV company. So what we’re going to do is we’re going to blend the edges together. What we’re going to do is we’re actually going to layer overlap the two projectors on top of each other just subtly. It might be something like 10% of the projectors will overlap with each other.


Well, as we know, if we layer two projectors on top of each other, it’s going to create a little bit brighter of an image. So in that middle part, it’s going to be twice as bright, right in the middle. And it’s not going to look good, it’s going to look kind of weird the middle sections a little bit brighter than the rest of it. So what we’re going to do is we’re going to do an act called feathering.

Essentially, we’re going to soften up that blend and we’re going to slowly take it from basically 100% brightness down to zero on the edge, and then vice versa, 100% on the other. Basically what ends up happening is you have a perfect blend whereas one is dimming down on one side of the production, the other’s going up and brightness.

It balances out. Instead of getting double brightness, you take two 50% you put them together, you get a whole. And that’s how you get the perfect blend right in the middle. Take a little bit of softening between them. You overlap them and you get one whole image on there. That’s the basics of projection blending.

And so when we do these three by one screen if you ever see your AV company trying to pitch you for one projector or two projectors stacked on top of each other to do these 30 foot by 10-foot screens, run in the opposite direction. That is not the way to do it. It’s not the smart way to do it. It’s going to look bad. Please help yourself and help me by not ever allowing that to happen. So, and again, this gets really, really technical when it comes to video stuff.

Extra Recommendations

My biggest recommendation, if you do those three by one screen, again, you’re doing two projectors side by side for a 30 foot. Again, if you do maybe a 60 foot, you might have four projectors. If you do a 40 foot, it might be three projectors side by side. And then I always recommend double stack those projectors. You get the double brightness, you get the backup, but anything goes wrong, you’re good to go. Can you imagine if you didn’t double stack these projectors and the left one at went out, you would only get half the screen on there?

Get A Projectionist Involved To Make Projection Blending Stand-Out

And that’s like, “Ah, that’s a nightmare to think about.” I had a client once asked me, he said, “What happens if it goes down?” And I said, “That’s what I asked you on the quote, walkthrough when we got rid of the projectors, right?” You’ve got to make sure, if you’re willing to take the risk and save the money, and you want to save money, you’ve got to be willing to take the risks that go alongside it as well.

So things to just kind of keep in mind when it comes to these ultra-wide screens that are super duper popular right now. You want to make sure that you have a very, very good, video engineer. Commonly your video engineer who’s going to do this, it’s called a projectionist. They understand the projectors, they understand the models, they understand how to tweak it.

So when they’re actually doing these blends, you’ll see them up there with a controller or a computer. And they’re literally nudging the projector over like one millimeter at a time and then stretching it and getting it perfect so that everything’s perfectly aligned. So having a good projectionist will make this look fantastic for you.

There are a few basics when it comes to projection blending. I hope this was really helpful for you for if you are looking to do one of these ultra-wide screens, you understand a little bit about the blending, how many projectors you need, everything like that. If you are doing a big corporate show, making sure you have redundancy and backup up there as well. And then also just some basics around understanding this idea that, if you take a 30K projector and stack another 30K projector on top of it, you’re not necessarily getting 60K of brightness, you’re not doubling the brightness.

Projection Blending: Conclusion

You might start to see this diminishing law of return. Man, crazy Wednesday today, so much tech coming right at you. I hope you found this helpful. I’d love to know, have you ever gotten a chance to do any projection blending or try to do this at one of your shows? Leave a comment down below of a horror story of when you didn’t have a backup in how you handled it.  I love to hear it down below. If you enjoyed, make sure to like subscribe, do all the things. We’d love to hear from you. We have so many Whiteboard Wednesdays now. So make sure to go back and watch all those old ones too, because there’s so much good stuff. And this has been Will Curran, Whiteboard Wednesday. We’ll see you next Wednesday. Gosh, let’s go project some awesomeness out in the world.


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Will Curran

Author Will Curran

Information junkie, energetic, and work-a-holic are just some of the words we can use to describe Will Curran. Aside from spending 20 out of 24 hours a day working as the Chief Event Einstein of Endless Events, you can catch Will ordering a chai latte or watching The Flash with his cats. He is also well known for his love of all things pretzels.

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