Low Light Streaks - Is my camera faulty?

Looks like fixed pattern noise to me on mine. Thing is, it shows up at *every* ISO. Underexpose by 2 EV and it shows up on skin, faintly. By 3 EV it's quite noticeable. Expose at what the camera thinks is "proper" exposure and it doesn't show up unless you're at a crazy high ISO.
 
Nighthawk said:
Man, I'm open to anything right now. I've tried the black wrap suggested by Peter with little success but I'm not in the same lighting situation that I was before. I'll have to retry tonight. I'm trying to keep everything as consistent as I can. I'm also trying the suggested NR up with everything else down while recording for hours straight. This is where I'd kill for LIVE out right now. Would be much easier to judge in real time what's going on.
Click to expand...


Why don't you send it to a service department with evidence showing the problem. Complaining, Aluminum foil, mystic tribal sayonses won't rectify the issue.

It's an issue built in the camera, nothing you can do about it personally. However, if you get it to Panasonic with adjoining evidence to substantiate your issue, this will start a case file. We can then keep track of this, and build a very strong case with multiple service cases on this to get it resolved.


.
 
Barry_Green said:
Looks like fixed pattern noise to me on mine. Thing is, it shows up at *every* ISO. Underexpose by 2 EV and it shows up on skin, faintly. By 3 EV it's quite noticeable. Expose at what the camera thinks is "proper" exposure and it doesn't show up unless you're at a crazy high ISO.
Click to expand...

Hi Barry & others: Just for clarification, can the GH1's REC MODE menu ISO INCREMENTS feature be used when recording video?

[100]/[125]/[160]/[200]/[250]/[320]/[400]/[500]/[640]/[800]/[1000]/[1250]/[1600]/[2000]/[2500]/[3200]

If so, is the noise/banding issue favorably affected by using, say, ISO 125 or ISO 320 etc. instead of ISO 100 or 400?

I dimly recall maybe this was discussed awhile back, but maybe some of these in-between ISO settings are less noisy than the "normal" ISO settings -- that is, if they're available for shooting video at all.
 
PappasArts said:
Why don't you send it to a service department with evidence showing the problem. Complaining, Aluminum foil, mystic tribal sayonses won't rectify the issue.

It's an issue built in the camera, nothing you can do about it personally. However, if you get it to Panasonic with adjoining evidence to substantiate your issue, this will start a case file. We can then keep track of this, and build a very strong case with multiple service cases on this to get it resolved.


.
Click to expand...

Normally I'd be all over your suggestion as this is pretty big issue but I start shooting with these cams next week. I've got no choice but to plow ahead and carefully watch my lighting situations while working on a possible solution to lessen the problem.
 
It happens at all ISOs. And yes those intermediate ISOs are available in video.

I'm not sure what the idea behind the "some in-between ISOs are less noisy than certain steps" comes from. It looks to me to be universally to be noisier the higher the ISO goes. But even at the higher ISOs noise is very mild compared to something like an HD100 or HVX200.
 
Nighthawk said:
Normally I'd be all over your suggestion as this is pretty big issue but I start shooting with these cams next week. I've got no choice but to plow ahead and carefully watch my lighting situations while working on a possible solution to lessen the problem.
Click to expand...
You can see it in the viewfinder. I haven't found a situation where the FPN shows up on the bigscreen TV, where it didn't also manifest itself in the LCD or viewfinder.

The LCD is amazingly sharp and really shows a lot of detail.

If you train yourself to see the lines, you'll see them in the field.
 
Peter J. DeCrescenzo said:
Hi Barry & others: Just for clarification, can the GH1's REC MODE menu ISO INCREMENTS feature be used when recording video?

[100]/[125]/[160]/[200]/[250]/[320]/[400]/[500]/[640]/[800]/[1000]/[1250]/[1600]/[2000]/[2500]/[3200]

If so, is the noise/banding issue favorably affected by using, say, ISO 125 or ISO 320 etc. instead of ISO 100 or 400?

I dimly recall maybe this was discussed awhile back, but maybe some of these in-between ISO settings are less noisy than the "normal" ISO settings -- that is, if they're available for shooting video at all.
Click to expand...

Yeah, Kholi talked about this a lot. Can't go past 1600 ISO(or at least I can't) and I've tried what's termed 'native' ISOs like 160, 320, 640 etc. with much the same results.
 
Barry_Green said:
Looks like fixed pattern noise to me on mine. Thing is, it shows up at *every* ISO. Underexpose by 2 EV and it shows up on skin, faintly. By 3 EV it's quite noticeable. Expose at what the camera thinks is "proper" exposure and it doesn't show up unless you're at a crazy high ISO.
Click to expand...
Is it always the same pattern? I have no GH1 yet, but it sounds to me like this could be corrected in post to a certain extent.
 
What I'm seeing are vertical streaks in fixed positions, usually visible in lighter tones or caucasian skin tones, and the streaks are of usually red or green. The closer to proper exposure the fainter they are, the further underexposed you get the more visible they are.
 
Barry_Green said:
It happens at all ISOs. And yes those intermediate ISOs are available in video.

I'm not sure what the idea behind the "some in-between ISOs are less noisy than certain steps" comes from. It looks to me to be universally to be noisier the higher the ISO goes. But even at the higher ISOs noise is very mild compared to something like an HD100 or HVX200.
Click to expand...

Thanks, Barry.

Partly my interest in confirming noise characteristics at all ISO settings is to determine which GH1 ISO is really the least noisy. I believe there were discussions online that some other DSLR actually had lower-value ISO settings which were found to be noisier than some of its higher value ISO settings.

As to which is likeliest to be the least noisy, ISO 100 might seem the obvious answer. But until someone tested it there was the possibility that ISO 100 on the GH1 could actually be like -3db gain on a broadcast camera: According to Art Adams, -3db can be problematic compared to using 0db. See:
http://provideocoalition.com/index.php/aadams/story/no_pain_no_gain/

Counter-intuitive, but he makes a good case.

But from what GH1 users are saying here, ISO 100 really is the least noisy setting on the GH1. Good to know!
 
Last edited:
-Vertical lines can not be fix in post
-WYSIWYG, the VF will show them very clearly as Barry said.

I was looking at some more footage I took this weekend and it looks like that on 720p mode the lines hardly exist at list outdoor.

Barry and other respected members of the community, any logical/technical explanation???

Thanks.

Johnnie
 
OPHERBA said:
-Vertical lines can not be fix in post
Click to expand...
Of course they can be fixed in post. You just need the right filter to do it. Even if the filter does not exist yet, you would be surprised what Digital Signal Processing can achieve.
 
Dear pailes, could not fix this with my Windows Movie maker:

1247692777.jpg



All kidding aside, it should not be there in the first place, or at least so severe.


Thanks.

Johnnie
 
Barry_Green said:
Looks like fixed pattern noise to me on mine. Thing is, it shows up at *every* ISO. Underexpose by 2 EV and it shows up on skin, faintly. By 3 EV it's quite noticeable. Expose at what the camera thinks is "proper" exposure and it doesn't show up unless you're at a crazy high ISO.
Click to expand...

I concur with this assessment on my camera.
 
Barry_Green said:
Looks like fixed pattern noise to me on mine. Thing is, it shows up at *every* ISO. Underexpose by 2 EV and it shows up on skin, faintly. By 3 EV it's quite noticeable. Expose at what the camera thinks is "proper" exposure and it doesn't show up unless you're at a crazy high ISO.
Click to expand...

Just wondering: Is it favorably affected by Film Mode settings such as Smooth or Nostalgic? Does it disappear in any of the B&W modes (in other words, does it occur only when recording color video)?
 
Comforting to see that all of us that have this problem, indeed, have the same problem but why do some like Ken7, and I'm assuming others, not have this problem? Different batches or suppliers for the sensors? This issue is more serious to me than the 'mud' issue in that I planned to be very cautious as far as camera movement goes. There doesn't seem to be a workaround at the moment other than supplying more light than I particularly envisioned using for my shoot.
For what it's worth I'll be emailing Panasonic with a link to this thread on the outside chance it will be looked at.
 
I don't think mine is that severe, indeed I have never noticed until tonight when I began looking for it. It only shows up when I underexpose and stop down the lens quite dramatically.

When I do that, on white surfaces there seems to be a set pattern over the image. It doesn't really move and it isn't speckled like noise, it just hangs there.

I think this will be something to do with the CMOS readout, some kind of phenomenon related to the CMOS technology.

Going to look it up...
 
As far back as 2004 when CMOS sensors progressed to the point where you could use them in DSLRS, people had a few banding issues with the Canon 20D.

http://forums.dpreview.com/forums/read.asp?forum=1019&message=11300831

The gist of it seems to be:

A CMOS sensor analogue to digital convertors are on each row and uses amplifiers which are linked together, and sometimes they spill over onto adjacent rows causing the banding effect. Also, on very fast CMOS sensors like the one in the GH1, according to Wikipedia it uses gate materials on the rows which lower the voltage threshold. I don't understand the engineering but it's necessary to speed up the read out of the sensor. However without a strong current, the current can 'leak'.

The problem happens regardless of what ISO, etc. you select. The PDF document linked to in that thread also suggest that certain CMOS chip wafers coming off the factory production line are more prone than others.

Panasonic haven't been making CMOS for as long as Canon. Maybe they still have some issues to dial out. Performance is excellent, but the GH1 can have as many artefacts as an Egyptian tomb if not handled correctly. Don't underexpose... darken in post?
 
Last edited:
Nighthawk said:
That's one thing I've never tried yet. I'll give it a shot.
Click to expand...

I did this already, and no I do not think the problem was "eliminated" when you go into the different film modes it is just changing the tone curve applied to the images after the readout. If my memory serves me correctly, depending upon the situation it could make the banding better or worse, when the tone curve was steeper and the image more contrasty (i.e. the vibrant setting) the noise becomes ever so slightly more apparent. With less contrasty modes with more gentle tone curves (nostalgic) the banding is a little less obvious but it was still there. As always there is the caveat: I only shot one scene though to test this so I don't know how this problem plays out under different lighting/exposure situations.

EDIT to clarify I think the film mode either brings out or hides noise already in the image, it doesn't reduce it.
 
You must log in or register to reply here.
Back
Top