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GH2 ISO noise bug at 320, 640, and 1250
  • 62 Replies sorted by
  • It doesn't matter how you change the ISO setting, so long as it is changed. If you see the picture get brighter or darker, it has changed.
  • Well, apparently the safer thing is to avoid 320 multiples altogether. Considering you always have a 1/3EV ISO setting in the vicinity, it's better to be safe and go up/down from the the offending ones...
  • One more thing, does this ISO issue affect video too???
  • As far as i knoiw all we are talking about is video.
  • Can noise reduction software help with this issue? I recently shot at ISO 1250 and now have this ugly noise. It was really unexpected, as I thought I had shot at 1250 prior to the shoot with good results. This stinks, as the shot cannot be done again. Is there anything I can do? I could have a much better image if I had lowered to ISO 1000 and opened a half stop even.

  • @cinepaint LOL, then remove the hack.... You're not selling this to us.

    Vitaliy did not add special code to add noise... Think about it.

    Noise is an analog component. If you did not see the same noise levels under the EXACT SAME conditions without the hack, it's due to (with the hack) you can NOW actually see more image detail from the sensor (and pre A/D), and that includes its noise floor; otherwise, it's smeared by higher compression. With no hack, you may think there's less noise, but instead you're left with less fine detail and the noise is now causing the smeared wandering macroblocks that are way worse than having the natural fine noise grain.

    Also, as mentioned many times here > When you are presented with the natural noise, you're noise reduction software can now actually make a better model (fingerprint) for removing the noise... Assuming you want to remove it.

    Sorry, but shooting at ISO 1250 and expecting low noise is insane, at least for an $800 camera.

  • @proaudio

    Your thoughts are well rationalized. I am intrigued, and will learn about this. I agree with you.

    I was mainly asking about my situation in the present. Which noise reduction software do you recommend?


  • @cinepaint

    Like yourself, we're all concerned about ANY camera's noise floor. Just jump over to a canon APS-C forum (other site) and look at all the noise threads.

    Many are using NEAT VIDEO PRO. Get yourself a large GRAY card that you can frame a large enough sample in the same light condition as your subjects you plan on shooting. Also, it's wise to shoot a color chart under this condition prior to recording. This way you can use the gray card for a noise reduction sample (since it is neutral and has no detail), also the color chart will be good for color analysis and use with your editing software's vector scope (if you choose). If you can frame a stepped gray chart, this will give you a better selection of where noise levels are the worse and you can sample that block within Neat.

    Also, look up tutorials using the noise reduction software. The goal is to remove noise without removing image detail. Of course, light things up and keep ISO low (if you can). Also be aware of the GH2 ISO bug> Just remember to always step down to your targeted ISO, so if you want ISO 320, go to ISO 400, then down to 320. Even in well lighted scenes you can have noise creep up in the shadows. Try to place the gray chart in those shadows, so you can clean this shit up later.

    Also, there are some users that use the same saved "finger print" noise file within Neat they created. Of course, this works to some extent, but since lighting may change the RGB balance (white balance / gray scale), chroma noise may change from shot to shot based on lighting. Sure this is "nit picking", but when you're after the best....

    IMO, stay away from any sharpening, unless you need it for image rescue and have no choice. Also sharpening internal or in post also "can" make noise worse especially if you don't know how to use sharpening control parameters in post. The internal GH2 NR is a "one knob" adjustment, so it's not that great. IMO, like most here set this to -2 (low as possible). Also, many run all the GH2 controls at -2. I normally do.

    Also, you may want to run a lot of your own tests (mid to low light levels) using a gray card with controlled lighting. Pull out that gray card under low controlled lighting and get a feel what's going on with camera white balance settings verses color temp of the light you are illuminating the card with. Pull up your tests in your editor and look at RGB parade, histogram, waveform display.

    Check RGB parade and make sure you're not clipping a channel (It may surprise you). Watch the RED channel, especially under daylight balance setting, this can drive the RED channel noise levels. Also, within the editor you can pull up a a frame and look at each color channel and see where most of the noise is driven.

    Most cameras the BLUE channel is the worse, especially under tungsten (warmer lighting). Naturally, since BLUE channel is upped to compensate for the warmer lighting white balance.
    There's a lot of testing you can do on your own to find out exactly what's going on under different color temp lighting, This will allow you to maximize the GH2 performance.

  • I started shooting a film last weekend and as a rule I never let the ISO go above 400... My goal is ALWAYS 160 if I can .. I have to agree with proaudio4 in that shooting the charts is a really good idea and will make a difference in post for noise reduction. I have been testing out shian's ColorGHears and it has some noise reduction tools that seem to work fairly well. Its way better to add light, then to ISO up in almost any given situation.

  • I was looking back at some old HDV material the other day... boy, you think we've got problems with the noise floor... its certainly better than what it was.

  • Im definetively going to use the gray card tip. Excellent tip by the way

  • Thanks a lot for the explanation! Much appreciated. I will start thinking about and implementing these strategies more often.

  • Keep in mind traditional video cameras have an ISO/ASA of 320 and like Driftwood said look at some HDV stuff and compare your 320 ISO to that. IT'S WAY BETTER..fact...I cant even use the Canon XH_A1 at my work without cringing nowadays.Just keep your ISO lower than 400. If you need to catch Bigfoot running down the street or something jump up to 800 but in a theatrical production...with lighting...other than "for effect"....I don't see much need to go over 250 ISO most of time, using fast enough glass of course.

    *Lighting better and smarter is the easiest way to fix your NR woes....

  • Even a Red or Alexa is normally rated as 800 ASA. Many are considering a Red rather like 320 under Tungsten, because all silicon is weak in blue. So, I think a max of 320 is very realistic for the GH2, and for HDTV rez under controlled lighting it is quite competitive then with the hack. You have to be much more careful with lighting and exposure, though. A high-end camera is not that much better, but much more forgiving (well, the Red has far more resolution and the Alexa far more DR). I'd only go higher with the GH2 if I have NO possibility to add light and I'd prepare for heavy post processing then. Excellent article, proaudio4, BTW, I second Neatvideo.

  • Great point No Surrender, with fast glass and proper lighting, you can avoid most of your ISO hassles before they even become an issue.

  • A new finding from @cosimo_bullo: sometimes going from 640 to 320, you'll have the ISO bug also.

    So that reinforces the rule we'd decided on: for 320, 640, and 1250, switch to the setting 1/3 stop higher, and then back down.

  • The GH2 is my new toy. Love it!

    I hardly tried to find info about the base ISO of the camera. Couldn't find it.

    So, anyone knows what's the base ISO of the GH2? -base iso usually will give the best rendition in terms of latitude-

  • @YOSS: Base ISO is 160, I'm pretty sure. If I can get enough light, I always try to keep it at 160 if possible. I know that some people in the past sometimes preferred higher ISOs even in good light because the extra noise helped break up sky banding, etc. But with the latest settings from Driftwood, banding is much less of an issue, so there's really no downside to 160.

  • Hello Everyone :-)

    I'm frustrated :-(

    Is Panasonic going to fix this?

    When is the next firmware update going to be released?

    Do any of the hacks have lower noise than latest Panasonic firmware?


  • Please let me understand if I need always turn camera off at higher ISO, then turn on, go down on ISO value? Or just little play with ISO value up and down will make same result?

  • you don't need to turn your cam off; just dial iso from the middle row first, i.e. before going to 640 choose 800 first etc.

  • Agree, great video! Really good to see the differences. Now that I am aware of this, filming and photographing should be better. A bit strange that the GH2 does this, but now that the problem has been identified, we are all the better for it.

  • It's not a great video. He only tests black, with the cap on. That doesn't reflect real-world images, unless you shoot all-black videos.