Bloom is basically lights bouncing to create the glowy effect, that's how we see bright spots in real life.
So, by adding bloom to your poster can make your posters look A LOT better.
When I mean A LOT, I mean AAAA LOOOOT.

Bloom is often used by SFM artist or as we call "SFMers"
because it helps to cover up our imperfection

How I got to know "Bloom"

I was stalking someone's gallery which looked GORGEOUS although their artworks are very simple.
I took me about 2-3 days to know what was going on, it was the glowy effect that he had.
So I looked up only about glowy effects and found very very few resources and there was one that had a word "Bloom" in it.

So I started gathering information about what's called Bloom and tried some programs that can recreate bloom. I was pumped then.

When I first applied the bloom effect to my poster, DAMN IT LOOKED GORGEOUS.
Then I started trying various programs till my poster started looking worse. I tried MBL and didn't really thought that it was "IT" so I moved on.
Then It got me to the point to ask the artist that I mentioned earlier, he said that it was MBL.

So I stopped learning every other method and started focusing on MBL.

There are many methods for creating bloom effect.

I'll include methods that I use below.

Before getting into the actual tutorial, let's take a look at some examples.

Before:


After:



Before:


After:



Blooms are very scene dependent the best way to learn it is to pay attention to your surrounding and try to re-create irl blooms.

Here are the settings that I had on my MBL.





I usually have 2 diffussion effects, one for the actual bloom and one for subtle blooms.

Don't use it

For those who don't have MBL.

You can also create bloom only pure Photoshop but I won't go much into details because I'm encouraging you to use MBL.

Here is how you create bloom using only Photoshop:

1. : Duplicate your poster by selecting it and pressing Ctrl+J

2. : Add the "Levels" adjustment and clip it to the copy layer then move the middle triangle to the left as shown below.


3. Blur the copy layer using "Gaussian blur" but don't blur it too much to the point that you don't what the poster was about.

4. Set the copy layer blending mode to "Soft-Light"

Here are the results:

Before:


After:


Before:


After:

First mistake:
Setting the bloom size too high


Although this can be nice sometimes but it can also look messy.

Second mistake:
Setting the bloom grade too high


This will make the bloom that you see when you've just woken up

LordKnight
He's the artist that I mentioned at the very beginning. He is also very good at day time bloom.

SourceBird
He makes very cinematic bloom. He is very good at night time bloom.