Low Light Streaks - Is my camera faulty?

Hmmm. I only really noticed low-light streaks in one photo I've taken...and it was on the first day. Sitting in my room with lights off and blinds closed I've been taking high ISO pics with no streaking...maybe I'm just lucky...although I am also using a fast lens (Nikkor-S 50mm, f1.4)...but still it's pretty dark.
 
commanderspike said:
Was your original noise kinda yellowish in colour?

Is iExposure on or off?
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For me at certain exposure levels it was yellowish but at extreme underexposure it's more brown.

Never had iExposure on thanks to advise you gave in an earlier post.

From everybody's experience what's been the most successful 'film mode' settings as it relates to this topic especially in relation to NR?
 
When doing photos I've mainly been using "vibrant" because I don't do much post work on my photos. For video I've been doing a custom setting...I think -1 saturation, -2 contrast, -2 NR....I don't see why you would ever want to do noise reduction in camera...to me that sounds like it will be softening the image. Also with contrast it's better in my view to have it turned down so you get more detail in dark/bright areas...you can increase it in post....maybe this will help with streaks if there is more detail in dark areas? No NR, low contrast?
 
Caution: Do not attempt to manually clean the CMOS sensor in your camera unless you feel qualified to do so, and even then, it's possible you may scratch the sensor or otherwise permanently damage your camera if you are not extremely careful!

Having gotten that warning out of the way, I noticed the following article on the Luminous Landscape site (similar articles can be found elsewhere online, too):
http://www.luminous-landscape.com/essays/sensor-cleaning.shtml

If (if) the GH1's fixed pattern noise has anything to do with residue on the sensor's surface left-over from manufacturing, it's possible (maybe) something like the special Eclipse cleaning fluid and special Sensor Swabs mentioned in the article can clean it off, or reduce it. Maybe.

Note: Since this issue doesn't involve dust on the sensor, you may or may not need to use the CO2 sprayer described in the article.

YMMV!

However, since the voodoo process of leaving your cam powered-up for hours as a way to "burn off" phantom residues is basically _free_, it seems well worth trying it first before resorting to attempting to clean the sensor manually (with liquids & swabs) yourself.

I really hope the voodoo power-up burn-in method works, because needing to manually clean a brand-new factory-fresh sensor seems unfortunate (and might not make any difference).
 
I don't recommend cleaning the sensor, (unless it's dusty and the super sonic wave filter can't budge it!) I don't think the issue is to do with the phantom residue or anything like - and this won't be changed by cleaning the sensor anyway. There is a filter in front of the sensor anyway so you wouldn't actually be touching the sensor itself if trying to clean it.

CMOS banding is due the design of the technology.

I think the burn-in theory is the most convincing way to reduce the banding I have heard so far, and I myself noticed my camera improving in that regard after a few days of usage. I still would like to see actual pictures for proof of it working though and to what extent.

I have heard it mentioned the picture gets cleaned up when you press 'record'. Indeed, the fixed pattern CMOS noise does get cleaned up by the noise reduction when recording, but not in live view.

Could it be that the GH1 has some kind of intelligent fixed pattern removal software which learns over time where the pattern is and attempts to compensate for it row by row by averaging out the signals running through the sensor?

RE: Pixel Refresh. Manual says it needs to be run annually, to return the GH1's sensor to 'factory' conditions. No idea what the reasoning or technology is behind this.
 
Yeah agreed on sensor cleaning. BTW supersonic wave filter is the best technobable I've ever heard on a camera feature.

Well I know when you're taking photos in low light the liveview gets tons of gain turned onto it even higher than the theoretical max ISO that really shows banding (before you take a photo...) buuuuuuuuuuuut from what I've seen video doesn't change too much when you hit the button.
 
Thats interesting. On mine, the fixed pattern noise is always there in live view when gained up and under exposed - paradox I know, but possible to achieve with the live view.

When the video begins recording the fixed pattern noise is suppressed pretty well. Could my GH1 have learnt over time where the fixed pattern is and learnt how to compensate for it?

The banding (while recording) appears for me still - but not much. Only in extreme situation, i.e. when the scene is between complete darkness and low illumination, i.e. a moon lit sky with an F1.4 lens can be tricky. With no light present at all i.e. with lens cap on, there is noise even when gained up. It's only when the photon signal (on the sensor) is weak that it causes the pattern to appear - and in this circumstance, it is recorded (even at ISO 100) and not just when the live view is gained up.

You have to give the CMOS sensor strong enough light through slightly overexposing and avoid evenly shaded unexposed areas of white, etc.

I recommend slightly overexposing shots when you see banding, even if it looks washed out and the highlights are blown, you can still have something to work with in post when you darken it with software.

Better to get a healthy image out of the camera and correct that rather than getting an unhealthy image out and worrying about reshooting or correcting the bad image in post which is much more difficult than just tuning the levels!
 
Peter J. DeCrescenzo said:
If (if) the GH1's fixed pattern noise has anything to do with residue on the sensor's surface left-over from manufacturing, it's possible (maybe) something like the special Eclipse cleaning fluid and special Sensor Swabs mentioned in the article can clean it off, or reduce it. Maybe.
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Yeah I've said this now twice in the past couple of weeks.... Seemed no one wanted to run with it. That said, I hope that could fix this; then it's not an issue!

The burn in thing still baffles me, though I can understand it. If it is however on a senors/transistor level, then what is burning in?

Btw cleaning sensors glass, The actual sensor is sealed. This is not a problem if you use correct tools. I have been doing it since 2003.

.
 
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Well, I have an "unmolested" GH1 and I'm willing to try this. If someone wants to explain to me how to "burn it in" and we agree upon what to shoot as a sample then I'm more than glad to do a before and after. I also have eclipse solution and pec-pads. I have no qualms about cleaning the sensor on the GH1. I cleaned the sensor on my 30D plenty of times without issue and it's harder to get at than the GH1's.
 
The best burn in method that I had to due with Saticon and Plumbicon tube broadcast cameras was I would film a TV full frame with CNN etc on and this would remove for the most part burn in that happen from lights or the sun out in the field... It would take about 12+ hours, however it worked.
 
Interesting. I could do that I suppose. What shall we use as a control point? What kind of situation best shows the streaks so that we can really have a decent before and after comparison?
 
admactanium said:
Well, I have an "unmolested" GH1 and I'm willing to try this. If someone wants to explain to me how to "burn it in" and we agree upon what to shoot as a sample then I'm more than glad to do a before and after. I also have eclipse solution and pec-pads. I have no qualms about cleaning the sensor on the GH1. I cleaned the sensor on my 30D plenty of times without issue and it's harder to get at than the GH1's.
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Ahh gold dust.

You can be of great service here my friend :)

Please shoot a short clip featuring banding, static shot with tripod, at a static scene with lots of bright objects in a (very) dimly lit room at ISO 1600.

Then after the overnight burn in where camera is turned on, plugged into mains, LCD & EVF turned off to save those components the stress, take the very same clip with the very same settings on the same tripod and see what you see.

Most importantly... let us see it as well :)
 
In addition to PappasArts' suggestions:

An analog TV displaying bright random "snow" (not tuned to a TV program) might be a good "subject", too.

Or: A computer monitor displaying a bright, random screen saver which never goes to black/sleep.

But my guess is -- if there's merit to the GH1 burn-in/cook-off theory -- just leaving the lens cap on while powered-up for hours might work just as well, if all that's really going on is the sensor & cam warming up a bit to hasten the evaporation of some mystery residue. Seems worth a try; can't hurt.
 
For what it's worth I've been cooking mine for over 20 hours now. The room is the same but the ambient light has changed but I've tried to maintain the most horrible streaking possible adjusting aperture and shutter speeds while maintaining a constant 1600 ISO. The results are really promising. The few times I've checked for progress the problems I had with lower ISOs is vastly superior than before. I'll be watching admactanium's progress and see how shooting at a moving screen etc. might improve it more.
 
Be careful, the manual says not to expose the sensor to sunlight for long periods of time.

It also advises to...I am not making this up...
"Do not use a paper bag as it can easily rip causing the camera to fall and be damaged."
 
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