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  1. Some of my vids with my minidv are dark, and I was wondering is there like a proven method to adjust the brightness and contrast to get the best picture, or is it just all about what looks best to you. I mean if you add to much brightness than the vid is overexposed, too little and its underexposed. I know in Paint Shop Pro 8 there is a automatic brightness/contrast button and you select it and it adjusts it to the best settings. Just what is the difference between brightness and contrast?
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  2. Always Watching guns1inger's Avatar
    Join Date: Apr 2004
    Location: Miskatonic U
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    It depends what tools you use. Most editors have at least basic brightness and contrast adjustments. Some have dynamic adjustments as well.

    Virtualdub has basic filters built-in, and better ones available for download.

    Avisynth has an even wider range, but is tougher to get started with as it is a scripted language.

    Sometimes it is more complicated than simple brightness/contrast adjustments, as dark DV video is often very noisy, and making it brighter enhances the noise. So then you need to filter some of the noise out.

    What tools do you have or are you familiar with ?
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  3. I forgot to tell you what I use. I always use VirtualDub for my editing. You are completely right though. Once you start messing with the brightness and contrast than it brings out the noise. I have the MSU Smart Brightness filter and I have the brigtness and contrast filter by Donald Graft. What do you recommend and in what order to load the filters. I always use the filters, resize, smart deinterlace, and MSU Denoiser.
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  4. Member edDV's Avatar
    Join Date: Mar 2004
    Location: Northern California, USA
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    Originally Posted by capman21
    Some of my vids with my minidv are dark, and I was wondering is there like a proven method to adjust the brightness and contrast to get the best picture, or is it just all about what looks best to you. I mean if you add to much brightness than the vid is overexposed, too little and its underexposed. I know in Paint Shop Pro 8 there is a automatic brightness/contrast button and you select it and it adjusts it to the best settings. Just what is the difference between brightness and contrast?
    Are you judging by the PC monitor? Burn a test DVD and play it to your TV before you adjust anything.

    An uncalibrated overlay is arbitrary.

    What is your player?
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  5. I am judging by my monitor, because I am just editing small clips to xvid have on my hard dirve.
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  6. Mod Neophyte Super Moderator redwudz's Avatar
    Join Date: Sep 2002
    Location: AZ, USA
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    Something else to throw in, though you may be aware of it. A computer monitor almost always shows DV darker than it will appear on a TV. And I agree, if you lighten a overly dark scene, the resulting video will usually look 'muddy', with lose of contrast, lack of detail and possible color shifts and video noise in the scene. As long as you correct these as best you can, it should work, though.

    Brightness is the overall 'lightness or darkness' levels of the video. Contrast is the amount of difference between the lightness and darkness' levels.

    VirtualDub and it's variants have more than a hundred filters available. The built in 'levels' filter is the first I use. I also like the 'White Balance Filter' by Jim Leonard. A comprehensive color adjustment filter is Colormill. colormill2.1.1.zip

    Some more general ones are here: http://www.thedeemon.com/VirtualDubFilters/ More here: http://neuron2.net/

    With VD, you many need to add a DV codec to work with those files: Cedocida DV Codec or the Panasonic DV Codec are popular.
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  7. I guess the biggest problem with all of this is once you tweak one thing you have to tweak something else to get the other thing right. What corrects the "muddiness" of the vid..sharpness? If anyone else has anymore info everything is appreciated.
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  8. Member edDV's Avatar
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    Location: Northern California, USA
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    Originally Posted by capman21
    I am judging by my monitor, because I am just editing small clips to xvid have on my hard dirve.
    A PC monitor will usually show spec video a bit dark. If you make it look good on the PC monitor, it will look bright on the TV. A good video player (like PowerDVD) offers nominal adjustment to PC monitors. Regardless, display card overlay settings set the overall video display levels.

    This is a SMPTE DV (NTSC) test chart. Monitor black (overlay) is adjusted to where the "pludge" negative black bar at the bottom right looks the same as the middle bar but bar 3 should look a bit brighter.


    Pluge (below black)----------------------------------------------------------------------------------^
    Middle bar (true black)------------------------------------------------------------------------------------^
    Third bar (slightly above black)--------------------------------------------------------------------------------^

    If Windows, do the right click "Save Picture As" to save the chart.
    Import it into your DV video and set overlay black from the color bar.
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  9. Mod Neophyte Super Moderator redwudz's Avatar
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    Here's a quick demo that might help for the subject:

    Original cropped photo opened in VirtualDub:



    Same photo with just the brightness dropped and the photo saved:



    Brightness raised on the saved photo with the 'levels' filter as best I could do. The tree trunk in the foreground is about the same level as the original, but the shadows and darker areas are washed out. (What I called 'muddy') The detail there is permanently lost. The photo is saved again.



    A bit of tuning with a RGB/Contrast/Brightness filter. Looks a little closer, but the detail is still missing in the tree trunk and the color is still off a bit. I could maybe improve it a bit more, but I'll never get back to where I started from. Same photo, saved a third time.



    That's just a very rough illustration of lightening a video and trying to fix the results when the quality is missing. And I just used brightness/contrast, levels and a RGB filter. With better filters like ColorMill and others it might look a bit better, but no way like the original.
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  10. So for example my vid the quality is okay its just to dark. When you go tweaking the brightness, contrast, and other levels it may lighten the vid, but it will also take away from the quality of the video.
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  11. Mod Neophyte Super Moderator redwudz's Avatar
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    It won't necessarily take away the quality when you lighten. In my illustration I darkened the photo to remove the quality, then demonstrated that you can't really recover it. This mostly applies when you have a very dark video that has already lost the details in the dark portions. But if you have detail there, you should be able to lighten it without messing it up too bad.

    But you should also notice that the colors do shift somewhat and the contrast levels change. Just raising the brightness and changing the contrast is not really what you want to do first thing. Try the levels filter instead and try to balance out the dark/midrange/light levels first. Add saturation, RGB correction and brightness or contrast as needed last. Be most careful of the darkest part of a scene. That's where there is less detail information.

    This is a common problem with DV. Commercial DVDs or movies have just about perfect control of the lighting at all times. You won't see that often with DV. If you lighten up a dark area too much, you will usually get the 'muddy' effect. When you re-encode a dark area, you may also see some noise or blotches in the previous dark part of the video.

    Most important, don't make any final changes until you view it on a representative TV.

    What I do is make up a representative clip, maybe 5 minutes or so and try different filtering, then number the modifications, and burn to RW disc and play it back on a TV. Once you have a 'feel' for your computer monitor calibration vs your TV, it gets a bit easier the next time around.

    And I am no expert on any of this. I just experiment a fair bit with VD and follow the lead of others on our site that do know more about it.
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  12. Member AlanHK's Avatar
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    Location: Hong Kong
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    See this thread for some ideas: http://forum.videohelp.com/topic300827.html
    What you want to do is change the brightness levels, but not linearly, otherwise you'll wash out some parts.

    There are a few "autolevels" functions and plugins that can give good results.

    And as others have mentioned, you must make test discs and play on your actual TV.
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  13. Thanks everyone for all the information and help. I will play around with it and see what happens.
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  14. Originally Posted by edDV
    This is a SMPTE DV (NTSC) test chart. Monitor black (overlay) is adjusted to where the "pludge" negative black bar at the bottom right looks the same as the middle bar but bar 3 should look a bit brighter.
    A word of warning about using this image: most DV encoders will perform a contrast squish when converting a JPG file. The resulting DV will not have any blacker-than-black data.

    Here's a type 2 DV AVI file with the proper levels:

    pluge.zip
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