Fix Dark Video??

Walleye2 wrote on 9/20/2004, 6:41 AM
I think I know the answer to this question, but maybe one of you smart people has a solution to my problem, or at least something that might help...
I have video from a recent wedding reception I attended. My camera is a Panasonic GS70 3CCD, not known for great low light capturing. The video from the reception is very dark - even with the shutter speed set as slow as possible and iris/gain set to 18db the image is so dark you can just see what is happening. I have added the Brightness/Contrast filter and done as much as I can with that to improve the image but it still looks pretty bad. Adding the Black & White filter to convert to B&W helps a bit.
Are there any other tricks, short of buying a new camera or adding light during shooting, that I can do in Vegas to improve the image?

Rick

Comments

Grazie wrote on 9/20/2004, 6:55 AM
A cammie for low light is a start. Lights are a must IF you haven't got a low lux cammie . .. now that you have this low light footage and you want to treat it - GIT YER 'ANDS off that Brightness control! NOW! - - - Ook ok ok .. . add the Sony Level FX and add a touch of GAMMA . . .works for me .. others have their opwn prescription/s . . tat ta . .Grazie
Walleye2 wrote on 9/20/2004, 7:28 AM
"with hands duly wacked..." Thanks much Grazie, I'll give that a try when I get home this evening - sounds promising.
Rick
johnmeyer wrote on 9/20/2004, 7:38 AM
Definitely do NOT use the brigthness controls on any of the fX. Use the Color corrector and then use the gamma control, or use the color curves. Use the Videoscopes to make sure you don't overdo it, and make sure to check the entire length of the affected footage after you apply the fX.

You may find more information here:

Billyboy Tutorials
Walleye2 wrote on 9/20/2004, 7:48 AM
Thanks John,
Gee, why is it the obvious choice is hardly ever the right one. "Picture too dark.... ah, yes Briteness sounds like the right tool..." :-)
Rick
Grazie wrote on 9/20/2004, 8:02 AM
. .. he he he ... yeah .. . just gittin' me own back, after having my wrists slapped too! . . .

Grazie
johnmeyer wrote on 9/20/2004, 3:02 PM
Gee, why is it the obvious choice is hardly ever the right one. "Picture too dark.... ah, yes Brightness sounds like the right tool..." :-)

Yeah, I know what you mean. Although I don't shrink from criticizing Sony, I can't really blame them for this. Adobe, with their photo editing software, and many other companies, used the term "brightness" to describe the control that makes every pixel brighter.

This is not what you want to do!!

If you make every pixel brighter, then your darkest pixel is no longer pure black, and the pixels that were almost, but not quite, 100% bright are now in fact 100% bright, which means all the detail in your video highlights is totally gone.

Instead, you want to use the control usually called "gamma" (which can be found in the Color Corrector fX). The gamma control changes the middle-brightness pixels the most, and barely touches those that are almost completely dark or light. This lets you make the picture brighter without losing the "punch" you get from having dark shadows, and the crispness you get from still having detail in the bright areas. If you want total control, you can use the Color Curves fX, and can create any brightness curve you wish. For instance, you could leave completely untouched all pixels below a certain brightness, but boost those in the middle-upper brightness range, and still not alter those pixels that are at the brightest range of the spectrum.

If you enable the Videoscopes in Vegas and then use the Histogram view, you can see the difference between the Brightness and Gamma controls. When you increase Brightness, the entire display moves to the right, and stays exactly the same shape. When you use gamma, there is still a shift to the right, but notice that the shape of the whole distribution changes as pixels that were in the middle are moved to the right more than pixels that started out near the right-hand side.

For the most professional results, once you get the hang of what is going on, the Color Curves does the best job. The problem (which you can see with you own eye in the Preview window, and which is also easy to spot in the Videoscopes Histogram view) is that the Gamma control in the Color Corrector (and the one in the levels control) moves the dark pixels way too aggressively, resulting in "washed out" results. If instead, you put a control point at the midpoint of the color curves and then move that point orthogonally to the line (perpendicular), you get a much more pleasing result, with the dark pixels staying more or less in the same place.

I mentioned BillyBoy's excellent tutorials in my first post and provided a link to his site. Here is a direct link to his tutorials on using the Color Curves to fix dark or light or washed-out video:

Video Adjustment Tips Using Vegas Video
Downee wrote on 9/20/2004, 5:33 PM
If there's any single tool you NEED, it would be Color Curves to tweek the mids. I also often use Levels to make blacks slightly more dramatic.
NaperRick wrote on 9/20/2004, 8:20 PM
Guys thanks much for the fantastic advice. I couldn't get over how much better the quality of the video was adjusting the gamma rather than the brightness. I'll try the color curves next.
Everyday I learn even more that I don't know much about video :-)
Thank goodness for all the experience and knowledge on this forum.
Grazie, John & Downee - "you da Men..."

Rick