Perfect vignetting correction for any lens you own

[hyalinejim]

Because I'm a cheapskate who is recycling his 5D Mk II era EF glass on the latest and greatest Panasonic body thanks to the wonderful Sigma MC21 adapter, I can't take advantage of in-body camera corrections for things like vignetting and lens distortion. And sometimes I would like to do that. It's a lot of fun using the phase detect AF in the S5II to shoot wide open and get in-focus footage with my Canon nifty fifty. But wide open, that lens has something like 2.4 stops of vignetting. That can look really cool sometimes but other times it's not. I first noticed it when editing some interview footage shot against a plain white wall. I wanted to do a little bit of reframing and it looked kind of bad because of the heavy vignetting.

I know there are effects that attempt to add or remove vignetting, but I was interested to see if there's a way to do it perfectly, as you can when shooting RAW and using Lightroom. And there is!

First of all, I put a semi-opaque piece of white plastic over the lens, focused it to infinity, set the aperture to wide open, pointed it at the sky and did a manual white balance. The aim here, in terms of exposure is to get the brightest part of the image (the exact centre) at exactly 50 IRE. Or you can use ACES to make a linear change to the data to get it looking like this:

Then desaturate it, invert it and export as a 16 bit TIFF or similar.

Place this image file on a layer above your footage. Change blending mode to Linear Light and Opacity to 50%. Hey, presto! Bye bye, vignetting!

(Note: doing this in ACES linear gives perfect results, but it works pretty well in log Rec709 too - the center needs to be 50% IRE in both methods)

This is how it looks on real world footage.

Before:

After:

 

Obviously, this isn't as convenient as doing it in camera as you would need a different vignetting profile for each f stop. But it will allow you to finally shoot your Nocticron f0.95 or whatever wide open without that pesky vignetting! I'm not quite as flush as all that, but I'm quite pleased that my old Canon plastic fantastic that I had in a drawer behaves a little more like Panasonic's version which costs 4 times the price. And a simple Lens Distortion filter at -2 knocks back the distortion. Now if only there was a way of making the focus motor perfectly silent...

[PannySVHS]

Which niftfy fifty are you using? @hyalinejim I got the plastic fantastic 1.8 for free when I bought a 5DII with the L 24-105. Looking forward to using it for some photography soon.

[hyalinejim]

4 minutes ago, PannySVHS said:

Looking forward to using it for some photography soon

It's great for photos as you can one click the vignetting away in LR if desired. This is the one I have, which I think is the last version of it.

[PannySVHS]

I got the mark1 version. Looking forward to snap it away with the plastic fantastic!

And looking forward to your findings with the S5II and some moving images as well or stills of the caliber coming from the 300 or 400D you sent to your friends.:) @hyalinejim How does the S5II feel image and grading wise compared to dealing with colour from 5DIII Raw?