What are the name of these kinds of textures? Is there a place where I can generate / download them? I tried like rainbow lens flare but didn’t have much luck. I want transparent pngs that look physically based. I of course tried to reproduce them in photoshop and got a similar result but still doesn’t look as good as it should I feel.
Hey there @pkeod!
I use Photoshop to create those, but you can also use Optical Flares, an After Effects plugin.
These are pre-existing flare images, but you can transform and mix them so you get to the concept you’re after ASAP. Then, you can bring those to Photoshop and use them as a reference to create your own “rainbow lens flare”. 
The touch that makes them look “physically based” is simply to use them in an Additive material.
Have a nice day! 
It’s an iris i believe. Some of those go by a few other names too like spheric lens etc,
What it is, Is a ring* shaped artifact that has it’s 3 channels (or 2, Offset). In photoshop duplicate the image 2 times and set each one to be in an individual channel R, G and B.
An example use a ring gradient, smudge it a bit, Zoom blur it and do the above.
Great replies thank you all!
This forum of all places not allow transparent pngs to be posted? zips/psds would be useful too…
Transparent png may be possible, but attachments such as zips will be difficult to constantly check and moderate. If you want to share something you’re free to post a link to a dropbox or some other file share service
