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View Full Version : Noise reduction recommendations?



JackBayer
08-04-2009, 04:47 PM
Hi people!

After reading for actually months now I finally have a GH1 in my hands, yeah!

I was wondering, if there´re any conclusions out there about noise reduction? Does it kill detail in my footage? Should I pull it down as far as possible? (as I do with all the other settings) or is it a good trade off at certain settings?

I´m sure you pros know a bit more about that than I do so any hints are much appreciated!

Regards,
Patrick

Ben_B
08-05-2009, 10:31 PM
I've got it turned all the way off...noise isn't that bad a thing always IMO, I assume it must kill some detail, and you can always reduce noise in post!

Barry_Green
08-06-2009, 10:50 AM
Noise on the GH1 is really minimal and I found the noise reduction to not do much of anything. I spent some time with it off, then with it on max, and it doesn't seem to be all that powerful. I eventually settled on just leaving it at "zero".

PappasArts
08-06-2009, 11:24 AM
Noise on the GH1 is really minimal and I found the noise reduction to not do much of anything. I spent some time with it off, then with it on max, and it doesn't seem to be all that powerful. I eventually settled on just leaving it at "zero".

Barry,

What about detail and contrast settings? Have you compared smooth vs standard?


The NR does a little reduction especially if you dial up the ISO. I would think the cleaner the better before avchd encoding.

Ben_B
08-06-2009, 11:56 AM
On mine I have saturation reduced by one, contrast by 2, and I think detail (if I remember right is this a thing?) by 2....I assume detail is just sharpening don't want that..turning down saturation by 1 keeps things from getting overly processed looking, and keeping contrast turned down gives more detail and seemingly better dynamic range that I can then change in post all I want.

Barry_Green
08-06-2009, 02:55 PM
Dialing up the ISO is a major no-no as far as I'm concerned. I've seen shots go completely to hell on 1600 ISO. I'd only use that if I had no other choice.

I like cranking the detail up, it seems to preserve gradients and fine detail in flat areas. For example, I shot some footage of some seagulls, and there was a lot of fine feather detail in the wings, but after the GH1's compression got through with it, the whole wing looked like a gray smudge. So I took to cranking the sharpness up to +2, and the next time I shot seagull footage it was fantastic. It seems to introduce enough variation into the flat-ish areas that the codec doesn't just wash it all into one big smudge.

Curiously enough, it's not all that different from the "banding" issue you discovered on the XL1 years ago, and Canon came out and said "add gain to avoid the banding". The idea was to introduce enough variation that the codec wouldn't just lump it all into one big mush. It seems to work.

Ben_B
08-06-2009, 03:47 PM
Ahhh...so if it's adding sharpness before the codec gets it's hands on it rather than after it can make the camera notice change and record it in high detail areas rather than let them be smudges? Good to know! Yeah I never increase ISO past 400 if I can avoid it...and that's just for night stuff, shoot almost everything at 100 (or occasionally 200.)

PappasArts
08-06-2009, 05:36 PM
Dialing up the ISO is a major no-no as far as I'm concerned. I've seen shots go completely to hell on 1600 ISO. I'd only use that if I had no other choice..

Dialing up for me, is like 640 and maybe 800iso if I must. 1600, eeee that just for fun or doing noisy B&W..




I like cranking the detail up, it seems to preserve gradients and fine detail in flat areas. .

I believe I encountered similar results the other night. Just wasn't sure since it was not under controlled settings or at least a repeated shot with different settings for me to check.




Curiously enough, it's not all that different from the "banding" issue you discovered on the XL1 years ago, and Canon came out and said "add gain to avoid the banding". The idea was to introduce enough variation that the codec wouldn't just lump it all into one big mush. It seems to work.

Oh jeez that was 11 years ago I believe. They did actual add a slight noise to the base signal on all XL1's after that to try to circumvent it as well is what I was told. That is very similar.



What about color temp Barry? I notice that with more blue toned images ( Lower Kelvin ) that it appears to be less codec noise. Now I haven't done any testing yet. So maybe I'm just seeing things.



.

Barry_Green
08-06-2009, 09:20 PM
Most modern sensors are daylight balanced, and that means that they're happiest when being fed blue light. When fed tungsten light, they have to "gain up" the blue channel, increasing noise.

I don't have my hands on a GH1 right now so I can't verify if that's the case, but I would be surprised if it wasn't.

Ben_B
08-06-2009, 09:29 PM
That seems right from my experience but I have no really good way to verify...I am enjoying the imagery of a sensor being "fed."

PappasArts
08-07-2009, 08:13 PM
Most modern sensors are daylight balanced, and that means that they're happiest when being fed blue light. When fed tungsten light, they have to "gain up" the blue channel, increasing noise.

I don't have my hands on a GH1 right now so I can't verify if that's the case, but I would be surprised if it wasn't.


How about the codec part. During encoding, does AVCHD or alike react more favorably to a dominant color like a very blue, red or green toned image scenes. Do these codecs have a strong point with certain color temperatures, like the sensors.

.

Barry_Green
08-08-2009, 12:21 PM
Well, the codec strips out 75% of the blue and red tones in the image anyway, due to 4:2:0 color sampling.

But I haven't shot a lot of pure-color stuff, other than a ton of green foliage. And with foliage, sometimes it's utterly brilliant, and sometimes it's utterly horrid. There's a "monet" effect that happens in underexposed greens that's really annoying, and I haven't found a way to minimize it yet.

But as for the relevance of your question regarding how it relates to sensor balance, I don't know that and can't test bc I don't have the camera at this time.

Ian-T
08-08-2009, 12:27 PM
And with foliage, sometimes it's utterly brilliant, and sometimes it's utterly horrid. There's a "monet" effect that happens in underexposed greens that's really annoying, and I haven't found a way to minimize it yet.

It's funny you said this because I've noticed this same issue wioth a lot of videos. I can see some nasty looking green trees and brush in some videos...then others look so clean and crisp. I just don't get it. Lately I have been seeing a lot better looking foliage in folk's videos but when it's bad...it's pasty. I've seen this also in other cameras (not just the GH-1).

Barry_Green
08-08-2009, 12:29 PM
I'd love to know which other cameras, because I'd like to figure out what the bleep is going on. I did a bunch of side-by-side stuff between an HMC150 and the GH1, and the GH1 frequently slays the HMC150 in terms of total resolved detail, but when it came to the underexposed trees the HMC150 was far superior in rendering that shadow detail.

So I didn't know if it was a GH1-specific thing, or a sensor processing thing, or a CMOS thing, or a codec thing. I pretty much ruled out the codec because the same "monet" thing happens in MJPG footage. So if it's happening in other cameras that would be a highly interesting thing to know, might help us get to the bottom of it.

ROne
08-09-2009, 10:58 AM
I shoot a lot of natural stuff; I recently took the HPX171 and the GH1. The GH1 looked great until you saw some of the detail on the petals in wide-shots, they were a bit of a mush but the usual red/orange problem areas rather than greenery were present.

I've done a lot of projecting out on the Panasonic projector (AE-2000 1080p) and it generally looks great although sometimes edges can look very EE, and as you don't see this on monitors < 42" it's difficult to find the culprit.

My other concern is with the OIS/jello/telephoto combo, when used at the long end little judders are both stabilised and jello'd at the same time giving a mini-earthquake effect. I'm not sure whether it's the MOS or the OIS fighting. Either way panning around a room on telephoto appears to be another no no.

Don't get me wrong, I love this camera I've done so much with it (even shot some great stills) but you've got to be careful to get everything confined with your settings and shots.

Ben_B
08-09-2009, 02:29 PM
but when it came to the underexposed trees the HMC150 was far superior in rendering that shadow detail.


Was this with contrast turned to -2 on GH1?

Barry_Green
08-09-2009, 09:47 PM
Yes, I was running contrast -2 most of the time.

As for "panning around a room on telephoto", keep in mind that the OIS has a provision for allowing panning, so maybe that would have helped? You have to choose the specific panning mode, where it only stabilizes vertical motion and ignores horizontal.

ROne
08-10-2009, 12:59 AM
Ahh didn't even think of that, thanks Barry.

ROne
08-10-2009, 01:53 AM
Then there is the firmware upgrade for the lens

http://panasonic.jp/support/global/cs/dsc/download/fts/index.html

which lists this: 1. Improved the operation of O.I.S. in Motion Picture recording.

which I haven't done yet.

hmm