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Color Correction!!!?????

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Jeffrey Starr
Color Correction!!!?????
on Sep 25, 2010 at 12:21:54 am

Ok so I'm working on a few videos for the university that I just graduated from. One of which is a series of interviews of different faculty/staff. In these interviews I've been using 2 Canon 7D's. One as a steady shot and one as a floating camera getting "different" angles. Two of the interviews have color issues, that I don't know how to fix...and I need help.

In both of the interviews the "main" shot is wayyyy to "warm" very yellowish and the second camera looks normal. Is it even possible to fix this? Maybe it's possible to "meet" somewhere in the middle? I have FCP, Color, and Magic Bullet Quick Looks, if that helps.

Thanks.

Screen shots below:

http://www.flickr.com/photos/46896663@N03/5021842540/ (main shot for interview #1)

http://www.flickr.com/photos/46896663@N03/5021842574/ (second camera shot for interview #1)

http://www.flickr.com/photos/46896663@N03/5021842438/ (main shot for interview #2)

http://www.flickr.com/photos/46896663@N03/5021235305/ (second camera for interview #2)


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Steve Crow
Re: Color Correction!!!?????
on Sep 25, 2010 at 1:50:11 am

Absolutely the color can be corrected. What I am seeing in the first set of frame grabs is a difference in overall exposure and depth of field.

In the first set, camera one is more "face on" and the has a much deeper depth of field, you can also see the sun hitting the woman strongly on her left/camera right cheek area. I think what you want to do for this shot is try working with the 3 way color corrector filter in final cut pro to reset your white point and then also lower the overall exposure. That should help you out a great deal. Did you white balance before this shot or did you rely on the automatic white balance setting on camera one?

Camera two (still on the first set of screen grabs) is actually filming from her right/our left and has a much shallower depth of field. I suspect that the white balance settings were different and that camera operator had an angle that was more in the shade too which helped with the color issue - I think that's why the shots look so different.

You will have to tweak all the shots individually in order to get the two camera's clips to look closer to each other, it's not like you can create one filter setting or settings and apply it to a bunch of clips.

Once you have the basic white balance and overall exposure issues addressed THEN you can take a look at color grading the clips (each one individually again, sorry) with Color or Magic Bullet

Hey - don't feel too bad, shooting outside in harsh sunlight is tough! I recommend you get yourself a Fader ND which will allow you to both deal with this challenge and let you get a shallow depth of field without blowing out your camera sensor because of the wide open aperture.

On the second set of clips I see you where going for the shallow depth of field inside but what seemed to get you was the bright sunlight coming through a window? and hitting her right/our left cheek.

Again - adjust the white balance and exposure levels with the 3 way filter and see where you get to.

Camera two got a totally different look - I suspect the camera operator had totally different ISO and aperture settings so was able to get what looks like to be a very nice shot even though filming from the "sunny" side of her face. Looks like a totally different person from that angle!


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Steve Crow
Re: Color Correction!!!?????
on Sep 25, 2010 at 2:31:57 am

Oh, it also might be instructional to look at the XIF data housed in the .thm file generated for each clip. That way you can tell what the shutter, aperture and ISO settings were for each clip.

Also you would be able to see what lens was used on each camera - that might have played a role as well.

Just my two cents (well four cents given my earlier comments)

:-)


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Noah Kadner
Re: Color Correction!!!?????
on Sep 25, 2010 at 7:26:53 am

Yeah those are way fixable- as long as you don't blow out highlights or underexpose by more than a stop you can work miracles in post. Good contrast- plenty of range to work with in there...

Noah

Unlock the secrets of 24p, HD and Final Cut Studio with Call Box Training. Featuring the Canon 5D Mark II and 7D.


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Gianluca Bertone
Re: Color Correction!!!?????
on Oct 1, 2010 at 4:06:41 pm

Hi there, I think that two of the shots can be saved in a color grading session with Color, Da Vinci or Pablo, but it's impossible to say how to fix it posting on a forum.
However, I want to give you some suggestions for the next shooting sessions that can help you to be un a better position next time.
I. Set both cameras at the same iso and at same aperture like f4 and don't change the f stop try to maintain the same depth of field in both cameras it helps with your visual continuity.
II. Go in the picture style menu of your camera and select to shoot in neutral mode then lower 2-3 units of contrast. This adjustment will allow you to record more tones and you can always easily add contrast in post, but you cannot successfully remove it. So even though the image look a little bit flat you are in the right spot. Footage doesn't need to look good in your camera LCD but on a calibrated monitor later in post. This tip is really the key to pull out as much as you can from your hddslr, details in the shadow need to be visible we are not looking for solid black.
III. When you convert the footage from H264 mov to AppleProRes 4:2:2 or other video codec compare and contrast the footage "before" and "after" the conversion of the clip. It's rare that default settings in the encoding software will do a great job. Usually, in this task you loose f-stops and background goes darker than what the original H264 shows. So try different settings tweaking the sliders (contrast, brightness, exposure) but in a very saddle way 2-3 percentage units max at the time. Moreover, change only one at the time render it and evaluate it because if you adjust more than one variable at the time you get lost. I use mpeg streamclip which is a free software for this task but you can do the same with FCP or Compressor. Hope all of this would make sense to you. Ciao!


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Richard van den Boogaard
Re: Color Correction!!!?????
on Sep 25, 2010 at 7:28:44 am

To add to this: next time make sure you match your cameras in terms of white balance - operating on AWB in a multi-camera shoot is dangerous, so it's better to set a manual white-balance or use an ExpoDisc to determine it for you.

Richard van den Boogaard
cameraman / editor / video marketing consultant

Branded Channels
W: http://www.brandedchannels.com


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Jeffrey Starr
Re: Color Correction!!!?????
on Sep 25, 2010 at 7:46:45 am

thanks for your help everyone. the 3-way color corrector did a nice job. it's actually rendering right now. even though it seems fairly simple, color correcting is fairly new to me, so i appreciate the advice.

both cameras were on auto, which "seemed" fine at the time (it was hard to tell on the LCD in the bright sun. I've since gotten an eyepiece which I'll never shoot outdoors without again). i think the difference though was the lenses. the secondary shot, which appears fine, was shot on a cheap $200 canon zoom lens. while the "main" shot, the one that's too warm, was shot on a $1000 Zeiss lens, and i'm thinking that because the lens is way "nicer" that it over compensated for colors, because in normal lite situations the colors it produces are insane.

thanks a lot.


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Jeffrey Starr
Re: Color Correction!!!?????
on Sep 26, 2010 at 4:46:22 am

thanks for the advice guys. I have one more question.

This is what it looks like now...

http://www.flickr.com/photos/46896663@N03/5024586035/

http://www.flickr.com/photos/46896663@N03/5024586035/

is there anyway to lessen that over-exposure on her face?

I've tried just applying a basic brightness/contrast filter from FCP but it darkens the whole picture and doesn't look good. I've also tried a plugin called "Captains Blowout Fixer" and haven't had a ton of success with it so far.

Looking for some help.

Thanks


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Steve Crow
Re: Color Correction!!!?????
on Sep 26, 2010 at 2:43:21 pm

Once a clip is blown out I don't know of any techniques to save it, or to selectively return just a portion of the frame from white back to color.

Basically what's happening is the data is gone and all you have is white which is why I prefer to shoot slightly UNDER exposed and then you can pull out the details if you need to by raising the overall exposure to your liking.

Perhaps others have more advice for you! Best of luck!


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Richard van den Boogaard
Re: Color Correction!!!?????
on Sep 27, 2010 at 8:05:12 am

Under-exposing is generally good advice, but it all depends on the situation. Neither full white nor full black provide enough data to correct for. If only future cameras would allow for HDR and RAW processing...

You can consiously choose to blow out your background if your subject would otherwise end up as a black hole in high contrast situations. Unlike our eyes with a contrast-ratio of 1:20.000, cameras work in a range of 1:30 - 1:60, so you sometimes have to make such choices.

In this case you could have better under-exposed, as half of here face is now blown out (indeed no info to correct for) and then use a gentle spot-fill in Magic Bullet Looks to correct her left site a bit.

Another solution might be to go for a B&W look on your B-Camera; but that's a stylistic choice.

Richard van den Boogaard
cameraman / editor / video marketing consultant

Branded Channels
W: http://www.brandedchannels.com


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Chris Wright
Re: Color Correction!!!?????
on Nov 7, 2010 at 7:59:06 am

I know this post is late, but if you're wondering if you can squeeze some more detail back from highlights, you could try my program. It works 2x better than adobe's RAW. just resize the comp from sd to hd if needed.

ae cs3 aep
http://www.mediafire.com/?o5724wvxd07mkv7

also, an adobe highlight plugin works in some instances, i made a ffx preset for that too.
http://forums.creativecow.net/thread/50/857898#857909

or even import a .jpeg or .tiff sequence into Adobe After Effects with Adobe Camera Raw development settings applied.
http://podcasts.creativecow.net/after-effects-tutorials-podcast/ae-quicktip...

or topaz adjust.

http://technicolorsoftware.hostzi.com/


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Evan Hayenga
Re: Color Correction!!!?????
on Sep 30, 2010 at 9:33:02 pm

Hello Jeffrey,

I have some suggestions for you about color correction.
First of all let me say that my medium is film not video. Color temperatures are a entire complete science in itself when working with film. I also was a proof printer and color corrector in a professional photo lab so you can have confidence that what I tell you is not coming from an amateur.
What you need to start learning about is "color temperatures". Color correction refers to the process of fixing a shot that is too yellow green or blue.
If you are using quartz halogen or tungsten lighting the temperature in degrees Kelvin coming from those sources is around 3200K. This is the area of range you want to work with indoors. If you are using a different kind of artificial light the temperatures aren't going to be in this area. A lot of people in video are using those small curly cue lamps. But if you read the side of the bulb it will say it's rated around 2750K. When color temperatures drop they begin to look blue. 5500 is normal daylight at noon and 3200K is normal for interiors. If you try and shoot film balanced for daylight indoors you have to add a lot of yellow to correct the blue. Vice versa if you shoot film balanced for 3200K outdoors you are going to have add a lot of blue.

But remember I'm talking about film and your talking about video. Her's what probably happened. In video it's always important to "white balance" every shot you take. This will give your camera the information about the lighting temps and it will tell itself that this is white. Then it's able to correctly handle all colors in the spectrum. So always white balance every single shot. Next, you want to make sure that the lighting sources you're using are all the same color temperature. If you are mixing temps you will have a nightmare to solve. So check the fixtures or bulbs for their temps. It's normally a 4 digit number followed by a K. If you would like, I can send you a list of different light sources and their temperatures. That way you can make a fairly good judgment about the color temp if the bulb or housing doesn't provide you the temp.
Obviously the camera was not reading the light source properly when the shot turned yellow. Remember when color temps rise they turn yellow and when they drop they turn blue. The camera was obviously reading the color temp around 5000K or so, If the rest of the scene looked normal, chances are the color temps were around 3400K and the camera was "white balanced" at that temp. so when it moved into 5000K it rose in temp about 1600K and that's why it was yellow. The area of distance between the light source and subject will also make temps rise.
So, now that your totally confused try doing this next time,

1)Make sure all your light sources are the same color temp. Don't mix them.
2)Try and light the entire set before you begin shooting and don't change any positions of light sources until your done with that set.
3)Always "White Balance" EVERY SINGLE SHOT. If you take a shot of a man seated at a table then take a CU of an ashtray nearby you have to "White Balance" the area of the ashtray because your light source is at a different distance and your lens mm most likely changed if you zoomed in for a tighter shot.
"White Balance" EVERY SINGLE SHOT."White Balance" EVERY SINGLE SHOT."White Balance" EVERY SINGLE SHOT.
Even if your light sources gave different color temps "white balancing will solve the issue.
You people got it made having that feature at your fingertips. We don't have that luxury in film. we have to color correct lighting with either filters on the lens or gel filtration on the lights and this information comes from dozens of tables, charts and references.
I'll give you a little advice about video. You may already know it or not.

The digital image isn't really an image at all. when they say digital runs at 27,45 fps there aren't any frames either. The image is stored in the camera in a series of numerical patterns. Numbers are what the camera records not pictures. Video also needs a lot of light to get good color saturation but the latitude (f stops between light and dark is very small) 4 stops maybe on a good camcorder. That means when you are at the correct exposure you c have only 2 f stops above before your image gets hot spots and 2 stops below before you lose all detail in the shadows. But video needs a lot of light to look good so how do you solve this problem. Start using filtration on your lens. Mainly Neutral density and Low Contrast or Ultra Contrast filters. They both do the same thing. They take the areas that are brightly lit and send that light into the shadow areas without changing any color at all in the rest of the shot. You could say they distribute the light evenly across the entire image area.
I have both the ASC manual and the ASC videographers manual. Did you know that the ASC video manual spends almost 60 pages covering filters while it only spends maybe 40 on lighting? That should tell you something.

Anyway, sorry for the email novel but I happen to know a lot about this subject and I'm always willing to share it with someone else to help them move ahead.
Take Care. Stay Creative. I'd love to see some of your images some time!
Best regards,
Evan Hayenga~


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