GH-1 GH-13 Fixed Pattern Noise: Breakthrough?

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emory

Active member
I'm starting a new thread because I can't find the one in which the initial findings were discussed. (My apologies to the two members who came up with this. I'm not trying to take any credit away from them.) The initial suggestion was to use the iA Mode on the camera's top dial to reduce FPN. The second suggestion was to use the P mode.

After doing a few initial tests I was more than sceptical. But now, after some tweaking, I'm convinced that I'm now getting significantly less FPN in lighting situations in which it's nearly unbearable with the normal manual settings.

I have no scientific explanation for this, and if anyone can prove that it's all humbug, I'll gladly stand corrected. But subjectively, I find the difference astounding.

The settings can be stored as one of the three custom settings, so they only need to be done once:

- Set mode dial on camera top to P.

- Set ISO to AUTO.

- Menu / record / aspect ratio: 16:9

- Menu / motion picture / rec mode / avchd

- Menu / motion picture / rec quality / FHD

- Menu / motion picture / metering mode / 1st

- Menu / custom / af/ae lock / af/ae

- Menu / custom / af/ae lock hold / on

- Menu / custom / movie button / ON !!!!

NOW:

- Menu / custom / cust.set mem. Select C1 C2 or C3 and SAVE these settings.

NOW set mode dial on camera top to CUST (I rarely change this, because I have C1 for photos, C2 for movies in manual mode and c3 for this "automatic" mode. Select the custom mode you have just created.

Now, it takes a while to become accustomed to this work flow, but after a while it becomes fairly intuitive.

Exposure is controlled by the wheel at the front of the camera. Press in on it so that the exposure compensation (-3 to +3) turns orange. Lightly press on the shutter release to focus (if using a Panasonic lens) and evaluate exposure. Turn the front wheel until the scene looks right. Tip: Panning slightly to a darker area makes the entire scene brighter and visa-versa. This is often quicker than turning the front wheel. When satisfied with the scene, press AF/AE lock on back of camera.

Now press DEDICATED MOVIE BUTTON on back of camera to begin recording. In many cases (especially dark scenes) you should see far less FPN than you normally would.


Observations and down-sides:

- Often what you see before you hit the movie button is not what you'll get when recording starts. Just stop recording, tweak briefly, restart.

- Occasionally the optimum settings for recording will look strange in preview (greyed-out whites, etc.)

- If you want to use a particular f-stop, you can: press the front wheel so f-stop and shutter speed turn orange, then turn the dial so the desired f-stop appears. (In dark scenes, the shutter speed indicated might be 1/2 second, but I think once you hit the movie button the camera records at the minimum 30th of a second for AVCHD.)

- If you lightly press the shutter release, you'll see the ISO the camera selects, but I doubt that this is a true indication, just a rough idea.


I can't explain why this appears to work so well, but it reminds me of what you can observe when taking photos in P mode: When you lightly press the shutter release, the preview often looks terribly noisy, but when you take the picture and review it, it's often creamy smooth (even if it's not always WYSIWYG -- just retake the photo).

This might just be a "Hail Mary" setting if you're caught in a terribly dark shooting situation with no lamps, but after playing around with it for a while, I find I can work quite well with it even in normal situations. You'll find yourself locking and unlocking the AF/AE lock button and turning the front wheel quite a lot, but it's easy to become accustomed to.

I'd be delighted if some of the technical experts in our forum could find the time to look into this. As I said, if you think it's a bunch of malarkey, just say so -- but please tell us the technical reasons WHY. Thanks! For the moment, this setting seems to indicate there IS such a thing as a free lunch.
 
thanks for the tips... but they just don't work me. it all actually makes things even worse;) cheers
 
Do you have a GH-1 or a GH-2? I have only tested on my GH-1, and I have always gotten better results with this mode -- sometimes only marginally better, sometimes dramatically better -- but certainly never worse.

At any rate, I think it's worth trying out.
 
I know where you're coming from, i think you were referring to the thread where i posted iA mode had much less band and noise than manual modes. The thread was about a Video reporter forgetting his HMC150 and only having a Gh1 with him. I agree with you, there is something allowing cleaner video, it may just be certain ISO are selected by the camera.

It does limit you to Panasonic auto lenses only, no manual lens will work.
 
emory said:
Do you have a GH-1 or a GH-2? I have only tested on my GH-1, and I have always gotten better results with this mode -- sometimes only marginally better, sometimes dramatically better -- but certainly never worse.

At any rate, I think it's worth trying out.
Click to expand...

GH1.

well, i'll give it another try later I guess
 
OK,

Had to try this with my new GH1 that is unhackable. I think it came out pretty good! Thanks so much to emory for posting the settings, they work pretty darn well:


When i first got the camera, I was disappointed at how much vertical banding I was getting unless it was slightly overexposed. The GH2 really is so much better. Now at least, especially for run and gun situations, the GH1 performs admirably with these settings. I tried to set up the GH2 the same way, but was unable to figure it out since some of the settings seemed to be unavailable or at least in places that I couldn't find them in. This makes a great custom setting that you can access very quickly.

Thanks again, emory!!

Tony
 
I refined emory's setting to the next level. Instead of P, I used S priority and saved into another custom mode. Plugged FD 50mm 1.4.

At EV 0, I set the SS to 60. Used the front wheel to set EV to -2. The LCD increased SS to 250, but it showed 60 in red color when the shutter button was half-pressed. So I guess the actual shutter speed is still 60. Pressed the lock button then the record button.

Here's a snapshop of the video.
Sequence 01.Still001.jpg

After boosting mid-tone input level,
Sequence 01.Still002.jpg

Frankly... I can't believe my own eyes.

Thank you, emory. You made my day.
 
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More extreme case. -3 EV. I used Vibrant mode -2, -2, -2, 0. Mine is unhackable GH1. WE0L.

A capture from original video.
Sequence 01.Still003.jpg

Boosted mid-tone
Sequence 01.Still004.jpg

Little more tweaking
Sequence 01.Still005.jpg

WooHoo... early X-mas treat?

Can someone please please hack the firmware 1.34 for GH1?
 
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Strange behavior. When the lock button was pressed, it displayed SS 60 and ISO 100. Moving around the manual focus assistance box took forever. Then I switched to creative movie mode. At SS 60 and ISO 100, LCD displayed pitch black. Moving around the manual focus assistance box was super fast.

I tried the same setting on MPEG video mode. It sucked.
 
In GH2, how to set EV to -2 when non-m43 lens is used in S priority mode? When the rear wheel is pressed, it goes manual focus assistance.
 
Great to hear that others are getting good results with these settings too.

I just wish we had a more "scientific" explanation for this, because then we could tweak the settings more intelligently rather than relying on trial and error and guesswork. I'm still hoping some of our technical experts might be able to look into this. (I don't want to mention any names, but one who immediately comes to mind has the initials "VK." ;-)

For the record, rambooc1 made the initial discovery in this thread:

http://www.dvxuser.com/V6/showthread.php?242979-Shooting-video-at-night-with-the-GH2

So thanks very much, rambooc1. Let's go on exchanging our findings...
 
This works amazingly well. I used the P exposure in Creative Movie Mode before, but this is much cleaner. Thanks emory, rambooc1. The camera almost sees in the dark now. I wonder if it's unlocking the IS03200 in still mode for video use? Anything above ISO1000 in video was unusable before this.
 
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Good morning good people

Oh what can I do with my GH1 today? emory, let me answer your question here so that others can hear, too.

I used Premiere Pro CS5. To boost mid-tone gray, I applied Fast Color Correction then adjusted the middle arrow button on the input gray bar. Also I modified RGB curve to bring out color.

Normally I overexpose slightly then apply color grading or play with RGB curve during the post processing. That works fine when there is enough lighting. When there is not enough lighting, overexposure setting introduces too much noise.

I picked -2 EV for testing purpose. 0 EV was brighter.
 
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Although I'm not a big fan of capturing low light, there is a case where low light is needed. e.g. a small street light at night. A scene mixed w/ properly exposed subject and underexposed corners/background. Try the original MTS. Very clean. No banding whatsoever.

 
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GH2 already has good low lighting performance. This trick closes the gap between GH1 and GH2 in low light performance.
 
In GH1, this trick certainly does the job when the ugly vertical banding occurs. AEL works on PASM and C1/2/3 modes. Spot metering seems the way to go. But I can't tell whether it's recorded in 30 SS or selected SS. When there is enough lighting, I'd use Creative M mode.

In GH2, Creative M mode is the way to go. AEL doesn't work on PASM & C1/2/3 modes when legacy lenses are used.

Creative M mode... lacks auto ISO option.
 
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