Which Video Effects to correct exposure and brightness between clips?

E

eco_bach

Well-known member
Hi
I am a novice in using Premiere and am using CS4, though I assume most of the workflow is the same in CS5. Before I attempt a color grade, want to make all my clips consistent in terms of exposure, or brightness and gamma.
I have just a few clips that were exposed 2-3 stops darker than the rest. The sheer number of choices in the Effects window in Premiere is a bit daunting to the newcomer. Which Video Effects are recommended to simply adjust exposure between clips? Right now I am trying a combination of Auto Levels, Levels and Auto Contrast but guessing there might be a simpler or better solution.
 
not sure if it exists in cs4 but in 5 i have had good luck with the Fast Color Corrector under video effects. apply it to your clip and under the Effect Controls go down to where it says Input Levels, a shaded bar with three arrows on it. move the midtone arrow around to lighten up the clip. It can add some noise, but it might save the day. Im sure there are a thousand other tweaks availble but you asked for something simple. see if it helps.
 
eco_bach said:
Hi
I am a novice in using Premiere and am using CS4, though I assume most of the workflow is the same in CS5. Before I attempt a color grade, want to make all my clips consistent in terms of exposure, or brightness and gamma.
I have just a few clips that were exposed 2-3 stops darker than the rest. The sheer number of choices in the Effects window in Premiere is a bit daunting to the newcomer. Which Video Effects are recommended to simply adjust exposure between clips? Right now I am trying a combination of Auto Levels, Levels and Auto Contrast but guessing there might be a simpler or better solution.
Click to expand...

The problem with 'auto levels/contrast', or anything 'auto' is that it may help an individual clip, but it will most likely not 'match' other clips. So, you need to look at the 'other clips', and adjust the lower valued ones to be as 'best' a possible match.

I've not got into using color correction in Premiere, so the above is sort of a 'general' thought.

In Photoshop, I usually have a 'reference' image up, and then work on the image to be corrected by directly comparing the tweeks in Curves or Levels, until I get 1) whites to match, 2) color balance and 'values', in the mids to match, and 3) shadows to match. Where most humans easily detect differences is in how human complexion is rendered, and so any wyrd variances there will be most noticeable. And of course some people have better color perception, and attendant memory, so they may be more inclined to fault subtle color shifts between shots...

I would look at the histograms of the shots, and check where the 'haystack' is placed, shifted right, that is bright, or shifted left, that is dark, relative to where the haystack of the 'good' shots are placed, then adjust curves on the lower valued images to better 'match' the good.

In color correction one can remove casts a couple of different ways... one is to 'boost' the missing color... or reduce offending colors... the reduce color tends to not have as much noise, as one reduces the intensity of that color, and any noise on that channel... boosting obviously boosts not only the color, but also the noise on that channel.

In terms of 'color' cast and 'adjust what'... one can recall how additive light works... R,B make Magenta, R,G make Yellow, and G,B make Cyan, or if the cast is a primary color, obviously reducing the primary color channel is in order...

I'll not mention that color correction should be done with a calibrated monitor in a room lit to a calibrated level, with a calibrated target projection system... well, only in passing will I mention it...
 
Thanks for the feedback. I've done a bit more research since I'm a novice PPro user and came across the Adobe CS5 Tips and Tricks white paper. On pages 23-24 it offers 2 suggestions which I think will work best for me.
1-use the shadow highlights effect
or
2- use calculations effect in combination with either screen or add blend modes(it gives a more detailed description in the white paper)
the advantage of the latter is that you're not introducing any additional noise in the image as it is lightened, which is usually what happens when you lighten shadow areas.
 
I use Magic Bullet Colorista and Looks myself. Both have an exposure control with settings in terms of stops. Makes it easy.
 
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