"Crunched Black Levels"
 

can someone tell me in plain english what "crunched black levels" mean.

i had a video engineer tell me my video had crunched black levels and i would like to know what that means and how i could fix this issue within premiere pro 2.0.

thanks

joel

fundamentally, it means you're clipping the shadows. In analog terms, your minimum IRE settings are near or below zero. Check your footage in a waveform analyzer to see where this is happening in your footage.

Or, in plainer english ... parts of your image that should be dark but not-quite-completely-black are in fact completely black.

So any detail in those areas, for example in your shadowed areas, has been lost ....

Ok thanks,

so i need some advice.....

I know where I went wrong. I had a couple of shots in low light of subjects with dark colored skin, so I changed the (RGB)white input levels from 255 to 220 or so and then the (RGB)Black input levels to around 10 or so. So if this crunches my blacks how can I make a scene brighter and add contrast and still not "crunch the blacks?" is it possible or is the footage lost...

Joel

Your mistake was setting the black level to 10. Use the Curves tool instead of Levels, and create a gentle slope.

Which "curves tool" are you referring to? I don’t seem to find a tool named "curves" in Ppro 2.0.


Thanks,

Joel
Sorry if I seem clueless, i am really not, obviously coloring in not my forte.

If you look under /Video Effects/Color Correction/ you will see Luma Curve and RGB Curves as two of your options.

Levels is a subset of Curves. With Levels, you can adjust White, Black and Grey levels - this would be equivalent to using Curves with 3 points specified(one at each end of the line, and one somewhere in-between).

Curves lets you add additional points to achieve, say, an S-shaped curve.

ok thanks i'll try it.......

blacks
 

Joel,

With dark areas you can also play with the gamma to see more detail.

Thanks for posting your question, I learned a couple things reading the posts.

I believe (although I am happy to be corrected on this) that adjusting a single-parameter "Gamma" control - which some applications provide - is exactly equivalent to dragging the grey level slider in 'Levels', while leaving the white and black levels at 255 and 0 respectively.

well i tried the RGB curves tool and looks ok to me and on the waveform as well hope the station will ok it.....


joel

Correct, Graham. The gamma adjusts the midtones.