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"Noise Reduction Tip for the GH2 thats MASSIVE"
  • theteddytheteddy

    Im sure this has been mentioned on Personal View somewhere but I'm damned if I can find it. In the link

    Drew from the Drew Network claims in episode 6 of Hacked GH2 that by shooting only in >white balance> incandescent (the little lightbulb icon) in Vibrant mode, and then correcting in post you can virtually eliminate noise. The theory being that its the red channel that is the culprit. I cant test this myself as I've only got a crappy consumer editing suite. Note that whats shown on You Tube is client ready footage, hence the crushed blacks. I think he uses CS 5.5. Does this actually work ? He gets to the point after the 5 minute mark.

  • 15 Replies sorted by
  • stoneystoney

    Take with a grain of salt. Usually noises are from red or blue channel, and that doesn't mean much.

  • Mark_the_HarpMark_the_Harp

    ^^what he says! I have tried the white balance thing out and I'm not particularly convinced that it works.

  • thepalaliasthepalalias

    While the general applications for this are more controversial, using white balance set to a lower Kelvin value (and Incandscent/Tungsten is the lowest preset) can help to deal with noise in shots where reds are otherwise overwhelming the other colors. You can do this more precisely by using the option to specify color temp. in degrees Kelvin. Just keep lowering it until your skin tones start to look really un-natural and then bring it back up to right around "healthy".

    I often use that approach when it is too tricky (or time consuming) to use a gray card, at least on single camera shoots. And keeping any channel from saturating has the side effect of making it easier to tell the noise from the signal, because if you are too close to the saturation clipping point, then there isn't much of a delta between the color and the noise.

  • theteddytheteddy

    @thepalalias Thanks for that tip and also the awesome job you did with the audio on the Sedna hack I use.

  • thepalaliasthepalalias

    @theteddy Glad it's helping you. :)

  • rikyxxxrikyxxx

    Why Vibrant mode?

  • CRFilmsCRFilms

    The guy doing the purple filter testing said he was using the Max Latitude Patch on his GH1 and he'd gotten the WB just right with his filters, but when he switched to a GOP1 hack the settings changed and the cleanest WB for MaxLat didn't work the same for GOP1.

    IMHO, there definitely is a correlation with hack settings and WB settings noise settings between picture modes. I tried to see if B&W settings would cause less FPN and a usable image in 3200 iso on the GH1 like the 12800 iso on the GH2 looks in BW. It didn't look as good as the GH2, but Smooth B&W setting got rid of a lot of the FPN vs the other BW settings and the noise left was easier to remove in post.

    Ultimately, the only way to really know which setting is best for your cam and Hack is to test WB in incriments of 500K from lowest to highest and see how it looks for you. I did this vid to see what my noise looked like at max iso looked like:

    One thing I found is when you start at low K and try to CC it warmer, it got rid of a lot of the FPN and noise. While if you started higher and tried to grade it cooler, suddenly FPN was visible.

  • theteddytheteddy

    @rikyxxx check out the link, a personal preference of his I think.

    @CRFilms Nice test. IMHO I couldn't see a lot of noise difference between the different kelvin settings. Will definitely try the "low to high" CC. I assume that bits in camera. Im a noob.

  • stoneystoney

    Or... is there sweet spot WB range? e.g. 2500~5000K

  • CRFilmsCRFilms

    @theteddy Tanks....and Vimeo compression hides some of the noise. I uploaded it at 1080p but now it says 720p...is 1080 avaliable to Plus users only? Either way the best way to tell yourself is to test your cam at similar settings. I wouldn't go to max hacked iso, but defenitely max non-hacked iso.

    By "CC" low to high I mean, if you record at 2500K, a cooler blue color, and try to warm up the colors in post, it wound up hiding lots of the initial FPN, BUT when I shot at 5-7000K+ and tried to cool the colors in post, it started showing the FPN that the warmer stock golden color hid. I'm a total CC noob so it's possible I'm not doing something proper, but you defenitely don't have a lot of room to play with the image at high ISO, high WB settings because of all the noise.

    @stonebat Eyepatchentertaiment said to me in a PM about filters....."leaving the white balance of the camera at its native WB and then filtering the incoming light to that temperature. On CCD cameras (F900 - DVX100) that brought a noticeable increase in Dynamic Range". It's possible the GH1/2 could do the same if we knew the native WB settings. Either way I do think there is a sweet spot...in my test, it felt like the camera was adding something artificial to the image at 5000K+ that wasn't there stock...it's own kind of digital noise.

  • DrDaveDrDave

    This is a long standing theory that has been discussed going back years to the HV20, maybe further. You may get a small benefit in NR, and you may also mess up your colors :)

  • 2many2many

    buy lights in stead of expensive post-production software :p

  • Brian_SianoBrian_Siano

    Okay, I have a noise reduction question. I recently shot some interviews, entirely head shots against a gray background. I shot at 1250 ISO, and there's noise. The footage is not unuseable, but I'd love to clean it up a bit.

    Now, I know Neat Video's the preferred means of eliminating noise. But I'd like to try the noise reduction tools in premiere pro and After Effects before springing for Neat. Sadly, I don't really know what the settings do.

    So, could someone point me to a good FAQ on the subject? (Or, suggestions for settings?)

  • DrDaveDrDave

    Brian, for whatever reason Neat Video just gives a bit extra. Make sure you render out to Cineform or other intermediate codec owing to the Premiere bug which ads noise as well.

  • nomadnomad

    Neatvideo works temporal, and that makes all the difference for moving images.

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