proper way of adjusting video brightness

[psyde]

hello all. my sony fdrx3000 by default records overly-bright, and i'm looking to adjust that to normal levels through color correction. is there a proper way of going about this?

i'm using tmpgenc for encoding/editing, and i've tried the "output yuv as ycbcr" option, and that somewhat fixes it, but some videos still remain too bright, and if i run the video through it again, it comes out overly contrast-y/hard on the eyes.

if i simply adjust contrast, it also comes out too harsh for my liking.

my other options are to lower brightness and raise contrast, which doesn't look too bad at all, but can make some darker scenes too dark. i could also instead lower gamma and again up the contrast as another option. but at what ratio would i do it at? i've experimented with 2:1 contrast:brightness ratio, and i've gotten some pretty good results. a 1:1 makes the video looks too dull imo.

anyway like i said, is there a proper way that professionals do this? brightness, contrast, gamma, any other options? or i would appreciate your personal opinions or anything you've had success with. thanks.

[LMotlow]

i'm using tmpgenc for encoding/editing, and i've tried the "output yuv as ycbcr" option

Don't do that. Output for SD standard should be CCIR601.

Which TMPGenc product are you using? I guess you know they've made a great many.

What does "overly-bright" mean? Does it means highlights and brights are glowing hot-spots and have no detail? Does it mean blacks and other very dark colors look grayed out?

"Brightness" controls black levels. Contrast controls brights. Gamma controls the middle range. Histograms help keep you within valid luma and chroma range.

my other options are to lower brightness and raise contrast, which doesn't look too bad at all, but can make some darker scenes too dark.

What that means is that you'll likely have to process too-dark or too-bright scenes separately, and rejoin them in editing. Does everyone do this? Those who know what they're doing, yes. Welcome to video post-processing.

[psyde]

thanks for replying, i'm using tmpgenc plus 2.5. when i say overly bright, i mean to say that the video is washed out. blacks are grey, colors are weak and empty, and they just scream for dark emphasis/contrast/lowering of brightness or gamma etc. some scenes are worse than others depending on the lighting. some scenes are fine.

i'm fine with processing the different scenes separately, but how would you recommend me doing it? from what you already said, i'm guessing that your suggestion would include all three controls - brightness, gamma and contrast. what kind of a ratio would i shoot for? i'm not familiar with what a histogram is. is it one of those graphs where the lines move when you adjust said settings?

it's probably dependant on taste, but like i said i'm looking wondering if there is a proper way of adjusting the controls whether it be brightness only, contrast only, a combination of both, or something else altogether to achieve true colors and blackness levels without it looking dull (lowering brightness only), or harsh (contrast only).

[LMotlow]

Wiit a minute, you're using a 4K camera, re-encoding with a standard def encoder, fiddling with the output colorspace.....? Maybe you should give us a little more information about your video source.

What kind of brightness "ratio" are you talking about? If you know what parts of the spectrum the controls are working with, you use your eyeballs to watch the adjustment, and you use histograms to make sure you've stayed within the legal video range of y=16-235 for YUV or RGB=0-255. That product has histograms to help you. It also has advanced color and levels controls for YUV and for RGB. Are you aware of the difference between working in those color spaces?

Here are links telling you what kind of info you get from histograms. It deals with camera histograms, but the graphics principles are still the same for all media:
Understanding histograms Part 1 and Part 2
http://www.cambridgeincolour.com/tutorials/histograms1.htm
http://www.cambridgeincolour.com/tutorials/histograms2.htm

Note that no one can give adjustment advice in detail without a sample of your video. If you don't know how to make and post an unaltered (unfiltered) short sample, let us know the format and codec information about your video. A stll image won't help much, it wouldn't tell us how your levels change and it's an unwanted RGB conversion.

[psyde]

ugh, well things are more complicated than i originally thought. i'll have a read at the links you provided and just work with that. thanks tho bud, i do appreciate your time.

[lordsmurf]

Are you making a judgement that it's "too bright" based on your own non-calibrated home computer monitor, iPad/tablet, or laptop?
Or the LCD screen on the camera?

Both are bad methodology, and you actually have no idea how it looks if that's the case.

[jagabo]

thanks for replying, i'm using tmpgenc plus 2.5. when i say overly bright, i mean to say that the video is washed out. blacks are grey, colors are weak and empty

In tmpgenc contrast makes darks darker and brights brighter, proportionally. Brightness moves all levels up and down, ie, everything gets darker, or everything gets brighter, by the same amount. Gamma is usually used to bring out dark (shadow) detail without blowing out brights (though you will lose a little bright detail). Exactly what adjustments you want to make depend on the source and the look you want.

It displays the input assuming rec.601 colors and levels. HD video is usually rec.709 and should go through a conversion. Otherwise your colors will be a little off, most noticeable in reds and greens.

https://forum.videohelp.com/threads/329866-incorrect-collor-display-in-video-playback#post2045830