If you've been working in Studio lately and noticed your lighting looks a bit flat, adjusting the roblox bloom effect threshold size is usually the first place you should look to add some depth. We've all been there—you place a neon part, and it either looks like a solid block of plastic or it's glowing so hard it's burning a hole through the player's monitor. Getting that "just right" glow is honestly a bit of an art form, but once you understand how the threshold and size properties actually interact, it stops being a guessing game.
Let's break down what these settings are actually doing under the hood, because the way Roblox names them isn't always super intuitive for everyone.
Understanding the Bloom properties
When you drop a BloomEffect into your Lighting service, you're basically telling the game engine, "Hey, I want the bright stuff to bleed color into the surrounding pixels." But the engine needs to know two things: which pixels are bright enough to count, and how far that glow should spread. That's where your threshold and size come in.
The Threshold is essentially your gatekeeper. If you set it to 0, everything in your game is going to glow. Your grass, your baseplate, the character's shirt—it'll all look like a hazy dream sequence from a 90s music video. If you crank it up to 4 or 5, only the absolute brightest things (like a Neon part with a high-value color) will trigger the effect.
The Size, on the other hand, is about the spread. It's the radius of the blur. A small size keeps the glow tight and sharp around the object, while a high size makes it look like there's a thick fog or a very dirty lens between the camera and the light source.
Why the Threshold matters most
I've seen a lot of builders get frustrated because they change the intensity but the glow still looks "cheap." Usually, the issue is that the threshold is set too low. If your threshold is at 2, and you have a white building in the sun, that building is going to glow. If you only want the neon lights on the building to glow, you need to raise that threshold until the white walls stop bleeding, leaving only the neon parts to pop.
It's a balancing act. You want the threshold high enough to filter out the "normal" parts of your world, but low enough that your intentional lights don't disappear entirely. A good starting point is usually around 2.5 or 3.0, but it really depends on your skybox and your "Technology" setting in Lighting (like Future or ShadowMap).
Tweaking the Size for realism
The size property is where you get to decide the "vibe" of your game. If you're going for a sharp, cyberpunk aesthetic, you'll probably want a lower size. It makes the neon look like it's actually part of the geometry. If you're making a magical forest or a dreamscape, a high size adds that soft, ethereal quality that makes everything feel a bit more magical.
Just be careful with high size values combined with high intensity. It can quickly lead to "eye strain" for your players. Nobody wants to play a game where they can't see the edges of the platforms because the bloom is taking up half the screen.
Finding the sweet spot for Neon parts
Neon is the most common reason people mess with the roblox bloom effect threshold size. But here's a tip: the color of your neon part affects how the bloom reacts to it. A "Vivid Red" neon part is going to glow a lot more intensely than a "Dark Red" one, even if your bloom settings are the same.
If you find that your neon is too bright, don't immediately jump to the bloom settings. Try darkening the color of the part first. If that doesn't work, then go into your BloomEffect and nudge the threshold up by 0.1 increments. It's a game of fine-tuning.
I personally like to keep my size around 24 to 30 for most projects. It's enough to give it a nice "bloom" without making the world look like it's covered in grease. If you're using the Future lighting engine, the bloom tends to look a bit more sophisticated anyway, so you can often get away with more subtle settings.
Common mistakes to avoid
One of the biggest mistakes I see—and I've definitely done this myself—is setting the bloom while looking at one specific area and then realizing the rest of the game looks terrible.
The "White Room" trap
You might be tuning your bloom in a dark room with one neon sign, and it looks amazing. Then you walk outside into the daylight, and because your threshold is too low, the entire sky is a blinding white blob. Always test your bloom in both the brightest and darkest areas of your map.
Over-intensifying
It's tempting to crank the Intensity up to make things look "cool," but intensity and size work together. If you have a huge size and a huge intensity, you lose all detail in your models. The roblox bloom effect threshold size should enhance your build, not hide the hard work you put into your 3D modeling.
How lighting technology changes things
It's worth noting that your choice of Lighting Technology (Voxel, Compatibility, ShadowMap, or Future) significantly changes how bloom is rendered.
If you're still using Compatibility, bloom is going to look a bit more "blocky" and less natural. In Future lighting, the engine handles light bounces and specular highlights much more realistically, which means the bloom effect can actually pick up on reflections. This is where the threshold becomes super important. You might want a neon light to glow, but you might not want the reflection of that light on a shiny floor to be just as bright. By raising the threshold, you can ensure only the primary light source is blooming.
Pro tip: Layering effects
Sometimes, one BloomEffect isn't enough. You can actually put multiple BloomEffect objects into Lighting. Why would you do that? Well, you could have one with a very high threshold and a small size to give your lights a sharp "core" glow, and another one with a lower threshold and a much larger size to create a faint atmospheric haze.
It's a bit more advanced, and you have to be careful not to tank your performance (though bloom is generally pretty cheap on resources), but it can give your game a much more "AAA" look than just using the default settings.
Wrapping it up
At the end of the day, the roblox bloom effect threshold size is all about personal preference and the specific atmosphere you're trying to build. There isn't a "magic number" that works for every game.
If you're stuck, try these "safe" baseline settings: * Intensity: 1.0 * Size: 24 * Threshold: 2.5
Start there, and then start moving the sliders. If things are glowing that shouldn't be, raise the threshold. If the glow feels too "blurry," lower the size. If the glow feels too "weak," increase the intensity or lower the threshold.
The best way to learn is honestly just to mess around with it. Jump into your game, open the properties window, and slide those numbers back and forth while looking at your brightest objects. You'll find that sweet spot sooner than you think, and your game will look a whole lot better for it. Don't be afraid to experiment—you can always hit Ctrl+Z if you turn your world into a giant glowing fireball!