Realistic Lens flare movement

[MANUEL_MOUSIOL]

I'm trying to find out how lens flare happens when a bright light source like the sun is off screen but still spills enough light into the lens, creating these flares that move accordingly to the lens/light movement.
i am trying to mimick more or less realistic behaviour to apply some flare in post.
Surely I could just randomly create a moving flare but I'd love to know the science behind it.
Has anybody experience or a good source about this?

[Ihno]

If you use AE, buy this: https://www.videocopilot.net/products/opticalflares/
Seriously there is no point in trying it yourself.
Everybody who don't have nuke and wants to make flares uses this plugin.

Fusion has a flare tool too. It isn't very beautiful, though. But it should give an idea of how they're moving. Its called hotspot. And fusion is free up to 4k

Also there is a preset/plugin package for Fusion https://gum.co/FuFlares. Still, not as good as the video copilot plugin but much nicer than the native one.

[MANUEL_MOUSIOL]

Thanks, I'm using optical flares. But if there is no visible light source like I'm talking about, I have to animate by hand. Question is where to put the flare and what movement to implement.

[joconnell]

The movement is very specific to the amount, shape and placement of glass elements in the lens you're trying to mimic so there's no one rule - where I work if we're doing lens flares on our renders there's normally also live action shots mixed in to the sequence so we have a look at all the things that come from the real lens and copy that. Have a search for veiling glare (the stuff washing over the lens you're thinking off), flare and halation.

This stuff could be useful too, if only as reference from proper lenses:

https://www.rocketstock.com/video-pa...E&gclsrc=aw.ds

[MANUEL_MOUSIOL]

Thanks for the input!

[dgruwier]

http://vincentwauters.com/programmin...are20-for-nuke
I think this would help you, it creates fairly realistic lens flares based on the content of the image by duplicating, rotating, flipping, coloring, blurring and distorting the source layer. It's much closer to a real lens flare than something like optical flares.

To get light to spill in from off-screen, you can use the overscan option in the camera overrides to render an extra beauty pass that extends beyond the original (at lower resolution and quality since it's not going to be seen directly). Then place the real beauty on top of the overscan, calculate the lens flare from that, and crop the result to final resolution.


Then there's this, if you can get it working:
http://bitsquid.blogspot.com/2017/07...ens-flare.html

[MANUEL_MOUSIOL]

unfortunately I am not using nuke and will not in the near future. looks amazing though.
and that second link...urg..I wouldnt even know where to start LOL
thank you though!

[ijzerman86]

We use optical flares with a light object in after effects.
We export the camera and position from max with max2ae from boomer labs(couldnt get to grips with state sets but this should also work).
Import scene data in ae, change the exported light position null to a AE light. Enable tracks lights as source in optical flares and boom, awesome lensflare 100% accurate.

[MANUEL_MOUSIOL]

Cool. Sounds awesome. have to check it out. Thanks!

[dgruwier]

Not that I think it's still relevant at this point, but for the record, this isn't only possible in Nuke - It's just that someone already did all the work of creating the presets, and it's probably a bit faster and easier to work with. You could do the same in After Effects if you had the time and inclination, using precomps and something like FL Out of Focus to create the lens artifact shapes.

[MANUEL_MOUSIOL]

The shape is not the problem but the right movement that comes from the sun hitting the lens offscreen.

[justini]

I would love to see this added as an option. Currently there's no point using lthe VFB lens effects in an animation if the effect turns off the moment the light source is occluded or goes off screen. Would it even be possible, given that rays are cast from the camera view?