View Full Version : Advice on severe backlighting???
April 14th, 2012, 01:57 AM
I had a situation (my fault) last weekend when after my fixed camera with a tight shot of the bride and groom at a wedding suddenly had harsh backlighting that auto-iris compensated for and, of course, the background (a vast expanse of water that the sun decided to reflect onto) and the couples faces are naturally under-exposed despite the camera using spot exposure. I guess the difference was just too much.
Now I know what went wrong and that cannot be fixed as it's done and dusted and I have around 6 minutes of under-exposed faces. What I need to know is what is the best plug-in compromise ???
I can get a reasonable exposure using Sony Brightness and Contrast by pushing the contrast centre to around 0.85 BUT I also can get a reasonable image using Sony Levels and lift the Gamma a bit.
Which is the best alternative ...I already know it's not going to be good but I'd like the best compromise possible ... what would you use to correct this the best way???
April 14th, 2012, 03:46 AM
do NOT use bright / contrast - it really screws your levels up....
that said, curves should help you out immensely.
post a screen grab and we'll have a play.....
April 14th, 2012, 03:47 AM
hey Chris, Do you have After Effects?
If so, you could apply a luma key to the footage first, then adjust the darker portions independently of the lighter, lift up their faces without blowing out the highlights.
You can do it in Vegas with BCC i think as well. Any plug in that gives you Luma keying ability should work.
April 14th, 2012, 03:50 AM
great idea Leslie, screen grab would be great, something to do at half time.
April 14th, 2012, 06:22 AM
Very much appreciated (nope I don't have after effects unfortunately)
I have posted a before which is the raw footage and then I quickly played with levels and set input start for black levels at 0.05 and Gamma up to 2.5 ...it's a bit drastic but it was just a start....If you guys can work some magic then that's awesome. The after pic is my roughly corrected one but it's quite soft and lacks contrast BUT you can at least see her face!!! In the corrected one look how much noise is on the groom's jacket!!! Ouch!!!
April 14th, 2012, 03:25 PM
I love the smell of Colour Correction in the morning :)
Had a play, the bottom 3 tracks (mute the top one) are prob how it should be done with mattes and masks, but in reality I would guess when you play the video the motion on the matte will look unnatural and chasing the highlight on her dress and that veil with masks will be a pain. It is nice to keep the detail in the sky though. The codec also seems to be breaking down in the bush across the water, another mask maybe? its a lot of roto for a wedding.
The top track is just a levels fx to bring up their faces a little, and keep within legal levels.
I also put a Neat Video filter on you bright version, I think you would have to to knock out the grain a bit ( its also blown out severely on the scopes, but you prob know that :)
April 14th, 2012, 07:08 PM
Nice job on very crappy footage!! Just to make matters worse I also dialled in the wrong scene file so just to start off the camera was already under-exposing!! I appreciate the effort and this is a wedding that's best to have the "move on and enjoy the next one" rather than fight situations that cannot be made any better than they already are!!
April 14th, 2012, 07:24 PM
i'd have a close look at fbmn's exposure corrector - brilliant little plugin...
April 14th, 2012, 08:15 PM
Here's my stab at it using a technique I found on the Sony Vegas forum some time ago.
April 14th, 2012, 08:34 PM
Mike, can you explain the theory behind the invert, adjust, then invert again?
also add my effort I guess
April 14th, 2012, 09:08 PM
Gerald, I wish I could but I can't as I "borrowed" it.
The technique came from a guy named malowz in the Help with Over Exposure! (http://www.sonycreativesoftware.com/forums/ShowMessage.asp?Forum=4&MessageID=645727) thread on the Sony Vegas forum.
I substituted the Levels FX for the Color Corrector FX as I wanted a bit more control over other things.
As always, it's a place to start and adjust as desired.
April 14th, 2012, 09:20 PM
I've used the invert, adjust, invert way to happiness on some occassions and while it's not as good as making it right in the camera, it has saved my butt enough for me to say thank you Mike for borrowing it and putting that out. It was a while ago and I wish I knew about it long before that.
Can't figure out how it works all I know is that it does.
April 14th, 2012, 09:56 PM
Yep that is a find, I had a play and mutated it a bit, but the the invert seems to be the key.
with levels on the bottom track,
an Overlay track with invert fx added above,
then more levels and neat video as an output fx.
IMO this is amazing, you can keep your blacks, lift your mids AND regain lost highlights.
I love this place
April 15th, 2012, 03:40 AM
Yep it is brilliant!! That what I used!! Thanks Mike that is really awesome...as you enable the plug-ins you can see how it works ...just tick the first invert and it makes a mask over just the couple...I figure that the gamma correction is then applied just to that almost white area that is around the couple and then the second invert takes everything back to normal.
Now, all you need to change is the gamma in colour correction??? I found that I had to drop the gamma from 1 down to around the .300 level to get their faces right!! (The bride is Asian and she is quite fair and would probably freak if I made her face too dark) I didn't play around with any colour correction levels but if I get a chance I might do so. Just for interest Gerald and Mike ...what settings did you use in the CC plugin???
A million thanks for all your efforts!! Yeah, I really do love this place too!!! Greatest Vegas users on the planet
UPDATE: I decided to play a little with the gain (took it from 1.00 to 1.050 and it gave me a tiny bit of extra contrast) I also noticed when the switching between camera two which was shooting guests and didn't have the blacklight issue, the main couple shot was quite under-saturated so the saturation went from 1.00 to 1.500 and the shots match very well....we need to give Mike a medal for discovering this..I'm happy now!!!
Nicholas de Kock
April 16th, 2012, 08:50 AM
Saved my footage, thanks guys!
April 16th, 2012, 10:49 AM
Cool technique. you can also lock onto specific color ranges and treat them differently... so you can boost the faces slightly and drop the suits back to a richer color by using a chroma key to separate it from the rest of the image.