Moire with video shooting

AndyHSP · 12-18-2013, 10:29 AM

Hi All,

I have purchased a new K-3 last week and I was testing the video quality on that camera..... what i have noticed is that there is lots of "MOIRE" or "Aliasing" in my video clips.
I referred back to the manual and I found on page 58 that i can switch on the Anti-Aliasing filter Simulator on the still photography only and it's not usable on the video shooting.

Have anyone came across this issue and what is the solution to fix it?

Your help is highly appreciated.

regards,
Andy.

Parallax · 12-18-2013, 10:31 AM

Are you seeing this only when played back on the camera LCD, or are you seeing it on your computer monitor as well?

AndyHSP · 12-18-2013, 10:34 AM

i can't see it on the Camera LCD but on my Macbook is really obvious.

SteveB · 12-18-2013, 11:31 AM

It's the line skipping etc used to reduce the resolution to HD in DSLR video that makes it very moire prone. If the whole sensor were used and then resized to HD you would lose the moire but the required processing would be too high to be able to get the required frame rates for smooth motion.

AndyHSP · 12-18-2013, 12:29 PM

Originally posted by SteveB

It's the line skipping etc used to reduce the resolution to HD in DSLR video that makes it very moire prone. If the whole sensor were used and then resized to HD you would lose the moire but the required processing would be too high to be able to get the required frame rates for smooth motion.

Thanks SteveB
I will give it a try and get back with the results.

cheers,

Steve.Ledger · 12-18-2013, 03:25 PM

You can't fix it - it's how video works on dSLRs. APS-C sensors are not 16:9 ratio for video for one thing.
As Steve mentions, it's the line skipping (you can see stepping/jaggies on diagonals in the video as well no doubt, though anti-aliasing helps the worst of it).
When Steve said If the whole sensor were used he wasn't saying this is what you should try - you can't, there's no option for this.
This is why smaller sensors appear to do better than larger ones. For example, the 1080p video from the MX-1 is actually very good.

Tanzer · 12-18-2013, 04:54 PM

You might try turning down the sharpness setting. It won't actually improve resolution, but it might help "soften" (or, de-emphasize) the severity of the aliasing. I've just started playing around with that on my K-01.

kenyee · 12-19-2013, 07:27 PM

Originally posted by Steve.Ledger

You can't fix it - it's how video works on dSLRs. APS-C sensors are not 16:9 ratio for video for one thing.
As Steve mentions, it's the line skipping (you can see stepping/jaggies on diagonals in the video as well no doubt, though anti-aliasing helps the worst of it).
When Steve said If the whole sensor were used he wasn't saying this is what you should try - you can't, there's no option for this.

You'd have to switch to the Panasonic GH3 to fix it...one of the few DSLRs that do this right, but it's m4/3...

neeviour · 12-19-2013, 07:34 PM

This does raise the question, while K3 relies on mechanical LPF simulator, how does it do with video? Does the Moire problem apply here at all? Do cameras with optical LFP and cameras without LPF have or have not same issue in this case?

Tanzer · 12-19-2013, 08:44 PM

The OP pointed out that unfortunately, the mechanical LPF does not work in video mode on the K-3.

Going from around 24 MP to 2.1 MP involves some pretty significant line skipping, so I don't think that you would see any difference when comparing a traditional LPF to a sensor with no LPF. Maybe it would be possible to kick up the K-3's mechanical LPF, but you fundamentally have the same (i.e., low) pixel density, so I have doubts that would help.

Sensors are getting better all the time. One of these days it will be common to read and process all the pixels on an APSC sensor, not quite there yet though.

Steve.Ledger · 12-20-2013, 07:22 PM

You can use a fast lens wide open and isolate the subject with a shallow DoF keeping the background blurry which reduces/eliminates moire on background objects, if the moire is happening with the subject's clothing, ask them to change?

Also you can try moving closer or farther away from the moire producing patterns, this often helps.

Tons of info on YouTube about it.
But if you want to sling a couple of thousand dollars at a GH3, go ahead.

osv · 12-20-2013, 07:38 PM

moire has been a big problem for tv and video for decades, it's not a dslr-only issue.

yes, the talent should never wear clothes that have fine patterns, that's a standard requirement on all broadcast tv stages... along with never wearing pure white clothes.

the only fix for moire is to put the area that's causing the moire into a slightly out of focus condition; some people will de-focus the entire picture slightly.. you can also try shooting from a different angle.

AndyHSP · 12-20-2013, 09:50 PM

After a good time of trial and error and some web search I came across this creative guy "Jorgen Escher" (FCP Plugins | Jorgen Escher) he created a plugin for FCP (This is what i use to edit my video clips) this plugin is really really easy to use and very helpful.
Do give it a try if you use FCP. As for de-focusing while shooting is not an option for me than i will stick to this plugin and make the changes later in the post production phase.

12-18-2013, 10:29 AM	#1
AndyHSP New Member Join Date: Dec 2013 Posts: 5	Moire with video shooting Hi All, I have purchased a new K-3 last week and I was testing the video quality on that camera..... what i have noticed is that there is lots of "MOIRE" or "Aliasing" in my video clips. I referred back to the manual and I found on page 58 that i can switch on the Anti-Aliasing filter Simulator on the still photography only and it's not usable on the video shooting. Have anyone came across this issue and what is the solution to fix it? Your help is highly appreciated. regards, Andy.

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12-18-2013, 10:31 AM	#2
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,332	Are you seeing this only when played back on the camera LCD, or are you seeing it on your computer monitor as well?

12-18-2013, 10:34 AM	#3
AndyHSP New Member Join Date: Dec 2013 Posts: 5 Original Poster	i can't see it on the Camera LCD but on my Macbook is really obvious.

12-18-2013, 11:31 AM	#4
SteveB Veteran Member Join Date: Mar 2007 Location: U.K. Posts: 685	It's the line skipping etc used to reduce the resolution to HD in DSLR video that makes it very moire prone. If the whole sensor were used and then resized to HD you would lose the moire but the required processing would be too high to be able to get the required frame rates for smooth motion.

12-18-2013, 12:29 PM	#5
AndyHSP New Member Join Date: Dec 2013 Posts: 5 Original Poster	Originally posted by SteveB It's the line skipping etc used to reduce the resolution to HD in DSLR video that makes it very moire prone. If the whole sensor were used and then resized to HD you would lose the moire but the required processing would be too high to be able to get the required frame rates for smooth motion. Thanks SteveB I will give it a try and get back with the results. cheers,

12-18-2013, 03:25 PM	#6
Steve.Ledger Veteran Member Join Date: Oct 2009 Location: Far North Qld Posts: 3,301	You can't fix it - it's how video works on dSLRs. APS-C sensors are not 16:9 ratio for video for one thing. As Steve mentions, it's the line skipping (you can see stepping/jaggies on diagonals in the video as well no doubt, though anti-aliasing helps the worst of it). When Steve said If the whole sensor were used he wasn't saying this is what you should try - you can't, there's no option for this. This is why smaller sensors appear to do better than larger ones. For example, the 1080p video from the MX-1 is actually very good.

12-18-2013, 04:54 PM	#7
Tanzer Veteran Member Join Date: Mar 2012 Location: Perrineville, NJ Posts: 1,375	You might try turning down the sharpness setting. It won't actually improve resolution, but it might help "soften" (or, de-emphasize) the severity of the aliasing. I've just started playing around with that on my K-01.

12-19-2013, 07:27 PM	#8
kenyee Veteran Member Join Date: Mar 2007 Location: Boston, PRofMA Photos: Albums Posts: 3,026	Originally posted by Steve.Ledger You can't fix it - it's how video works on dSLRs. APS-C sensors are not 16:9 ratio for video for one thing. As Steve mentions, it's the line skipping (you can see stepping/jaggies on diagonals in the video as well no doubt, though anti-aliasing helps the worst of it). When Steve said If the whole sensor were used he wasn't saying this is what you should try - you can't, there's no option for this. You'd have to switch to the Panasonic GH3 to fix it...one of the few DSLRs that do this right, but it's m4/3...

12-19-2013, 07:34 PM	#9
neeviour New Member Join Date: Dec 2013 Posts: 13	This does raise the question, while K3 relies on mechanical LPF simulator, how does it do with video? Does the Moire problem apply here at all? Do cameras with optical LFP and cameras without LPF have or have not same issue in this case?

12-19-2013, 08:44 PM	#10
Tanzer Veteran Member Join Date: Mar 2012 Location: Perrineville, NJ Posts: 1,375	The OP pointed out that unfortunately, the mechanical LPF does not work in video mode on the K-3. Going from around 24 MP to 2.1 MP involves some pretty significant line skipping, so I don't think that you would see any difference when comparing a traditional LPF to a sensor with no LPF. Maybe it would be possible to kick up the K-3's mechanical LPF, but you fundamentally have the same (i.e., low) pixel density, so I have doubts that would help. Sensors are getting better all the time. One of these days it will be common to read and process all the pixels on an APSC sensor, not quite there yet though.

12-20-2013, 07:22 PM	#11
Steve.Ledger Veteran Member Join Date: Oct 2009 Location: Far North Qld Posts: 3,301	You can use a fast lens wide open and isolate the subject with a shallow DoF keeping the background blurry which reduces/eliminates moire on background objects, if the moire is happening with the subject's clothing, ask them to change? Also you can try moving closer or farther away from the moire producing patterns, this often helps. Tons of info on YouTube about it. But if you want to sling a couple of thousand dollars at a GH3, go ahead.

12-20-2013, 07:38 PM	#12
osv Veteran Member Join Date: Mar 2007 Location: So Cal Photos: Gallery Posts: 2,080	moire has been a big problem for tv and video for decades, it's not a dslr-only issue. yes, the talent should never wear clothes that have fine patterns, that's a standard requirement on all broadcast tv stages... along with never wearing pure white clothes. the only fix for moire is to put the area that's causing the moire into a slightly out of focus condition; some people will de-focus the entire picture slightly.. you can also try shooting from a different angle.

12-20-2013, 09:50 PM	#13
AndyHSP New Member Join Date: Dec 2013 Posts: 5 Original Poster	After a good time of trial and error and some web search I came across this creative guy "Jorgen Escher" (FCP Plugins \| Jorgen Escher) he created a plugin for FCP (This is what i use to edit my video clips) this plugin is really really easy to use and very helpful. Do give it a try if you use FCP. As for de-focusing while shooting is not an option for me than i will stick to this plugin and make the changes later in the post production phase.