Weird Color

ivantan55 · 07-02-2013, 08:53 PM

Hi, I'm new in this forum... Please forgive me if I post this at the wrong place.. I've taken some photos during a dinner lately and I found this weird color pattern ( I don't know what people call it, appreciate if anyone can tell me the term) on my photos, maybe 7% of the total. The colors seem to melt/blend as one patch in it. Never saw anything like this before.. Can anyone tell me what happen & what I can do to avoid this from happen in the future? By the way, I'm using K5, Ver 1.14 with 50-135mm. Auto Iso setting.

Adam · 07-02-2013, 08:58 PM

Can you post a sample or two?

ivantan55 · 07-02-2013, 10:14 PM

I did but never mind.. here..

Sagitta · 07-02-2013, 10:24 PM

Its the LED stage lighting. As far as I know there is nothing you can do about it except buy a camera that doesn't have a CMOS sensor in it.

It has something to do with the light filters inherent in just about every modern camera out there.

Heres a thread from someone with a Canon grumbling about it.

Basically the sensor is divided into bits where one part picks up blue, one part red, and two (I think) green. What you see in your end photo is actually the sensor mixing those bits together to render the color as it should be.

The problem is that LED stage lighting is pure red, pure blue, etc, so you wind up 'losing' up to half to three quarters of the data you'd get under normal lighting, and you wind up with the results you see there.

You can see the effect in this shot of mine from the LED lights in the window (and to a lesser extent the OPEN sign).

There really isn't much you can do about it except use an old CCD camera if you're going in to shoot stage lighting.

EDIT II: I'm not sure if the K5-IIs would do this, since the moire filter is removed. it could maybe remove the LED effect as well? I somehow doubt it though...

Last edited by Sagitta; 07-02-2013 at 10:42 PM.

Sagitta · 07-02-2013, 10:39 PM

As an example... heres a shot I pulled from Flickr (credits to 'moarplease') of a concert. All those searing bright blue bits of light in the crowd? Cellphone and camera LCDs doing their thing on her poor Powershot's sensor.

ivantan55 · 07-02-2013, 10:45 PM

Hahahahahahaha.. I have to agree on you for that.. Everyone try to get the best angle they can during such event.. What I've post here is a hit and miss situation where I need to admit that I do have some great photos at the same distance shooting with different angle.. I just want to ask any experience pentaxian out there how I can reduce it further.. Thanks Sagitta for giving your input by giving some explanation together with sample photo for more understanding.. For everyone reading this, if you have similar prob and manage to solve it or wanted to share your experience here.. Please do so..

stevebrot · 07-02-2013, 10:50 PM

Wow! That is truly bizarre. Time to fall back to film?

Steve

calsan · 07-03-2013, 12:29 AM

So this won't happen on a CCD camera then? Does this mean the value of my K10d just went up?

Sagitta · 07-03-2013, 08:05 AM

Originally posted by calsan

So this won't happen on a CCD camera then? Does this mean the value of my K10d just went up?

As far as I know, it won't from what I read up on when trying to figure out the whys of this happening. I could be hilariously wrong though.

JinDesu · 07-03-2013, 08:18 AM

Part of the reason is because LED lights emit a very narrow band of the spectrum, unlike other forms of lights. This means that when they are bright, they are extremely bright in their spectrum. Any reflective surface will reflect that narrow spectrum of light at full blast - whereas normal lights broadcast in a larger spectrum, and some of that spectrum is absorbed by materials (like skin).

That's why you get some heavy color bleeding, and sometimes just fully blown out areas.

scratchpaddy · 07-03-2013, 08:30 AM

Originally posted by Sagitta

Basically the sensor is divided into bits where one part picks up blue, one part red, and two (I think) green. What you see in your end photo is actually the sensor mixing those bits together to render the color as it should be.

The problem is that LED stage lighting is pure red, pure blue, etc, so you wind up 'losing' up to half to three quarters of the data you'd get under normal lighting, and you wind up with the results you see there.

What you're describing is the Bayer filter. If that's the cause of the problem, having a CCD sensor won't help. Neither will having the K-5 IIs: the AA filter is supposed to prevent interference patterns between the Bayer filter and regular patterns in the subject. In the IIs, the AA filter is removed, but the Bayer filter is still there.

AFAIK, there are only two sensor types which won't cause this problem. One is Sigma's Foveon sensors. They sense all three colors at every pixel, so no Bayer filter is needed. The other kind is a monochrome sensor, for obvious reasons.

07-02-2013, 08:53 PM	#1
ivantan55 New Member Join Date: Nov 2012 Photos: Gallery Posts: 23	Weird Color Hi, I'm new in this forum... Please forgive me if I post this at the wrong place.. I've taken some photos during a dinner lately and I found this weird color pattern ( I don't know what people call it, appreciate if anyone can tell me the term) on my photos, maybe 7% of the total. The colors seem to melt/blend as one patch in it. Never saw anything like this before.. Can anyone tell me what happen & what I can do to avoid this from happen in the future? By the way, I'm using K5, Ver 1.14 with 50-135mm. Auto Iso setting.

07-02-2013, 08:58 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Can you post a sample or two? Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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07-02-2013, 10:24 PM	#4
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081	Its the LED stage lighting. As far as I know there is nothing you can do about it except buy a camera that doesn't have a CMOS sensor in it. It has something to do with the light filters inherent in just about every modern camera out there. Heres a thread from someone with a Canon grumbling about it. Basically the sensor is divided into bits where one part picks up blue, one part red, and two (I think) green. What you see in your end photo is actually the sensor mixing those bits together to render the color as it should be. The problem is that LED stage lighting is pure red, pure blue, etc, so you wind up 'losing' up to half to three quarters of the data you'd get under normal lighting, and you wind up with the results you see there. You can see the effect in this shot of mine from the LED lights in the window (and to a lesser extent the OPEN sign). There really isn't much you can do about it except use an old CCD camera if you're going in to shoot stage lighting. EDIT II: I'm not sure if the K5-IIs would do this, since the moire filter is removed. it could maybe remove the LED effect as well? I somehow doubt it though... Last edited by Sagitta; 07-02-2013 at 10:42 PM.

07-02-2013, 10:39 PM	#5
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081	As an example... heres a shot I pulled from Flickr (credits to 'moarplease') of a concert. All those searing bright blue bits of light in the crowd? Cellphone and camera LCDs doing their thing on her poor Powershot's sensor.

07-02-2013, 10:45 PM	#6
ivantan55 New Member Join Date: Nov 2012 Photos: Gallery Posts: 23 Original Poster	Hahahahahahaha.. I have to agree on you for that.. Everyone try to get the best angle they can during such event.. What I've post here is a hit and miss situation where I need to admit that I do have some great photos at the same distance shooting with different angle.. I just want to ask any experience pentaxian out there how I can reduce it further.. Thanks Sagitta for giving your input by giving some explanation together with sample photo for more understanding.. For everyone reading this, if you have similar prob and manage to solve it or wanted to share your experience here.. Please do so..

07-02-2013, 10:50 PM	#7
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Wow! That is truly bizarre. Time to fall back to film? Steve

07-03-2013, 12:29 AM	#8
calsan Pentaxian Join Date: Nov 2008 Location: Perth, Australia Photos: Gallery Posts: 1,548	So this won't happen on a CCD camera then? Does this mean the value of my K10d just went up?

07-03-2013, 08:05 AM	#9
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081	Originally posted by calsan So this won't happen on a CCD camera then? Does this mean the value of my K10d just went up? As far as I know, it won't from what I read up on when trying to figure out the whys of this happening. I could be hilariously wrong though.

07-03-2013, 08:18 AM	#10
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Part of the reason is because LED lights emit a very narrow band of the spectrum, unlike other forms of lights. This means that when they are bright, they are extremely bright in their spectrum. Any reflective surface will reflect that narrow spectrum of light at full blast - whereas normal lights broadcast in a larger spectrum, and some of that spectrum is absorbed by materials (like skin). That's why you get some heavy color bleeding, and sometimes just fully blown out areas.

07-03-2013, 08:30 AM	#11
scratchpaddy Pentaxian Join Date: Feb 2013 Location: Phoenix Posts: 3,361	Originally posted by Sagitta Basically the sensor is divided into bits where one part picks up blue, one part red, and two (I think) green. What you see in your end photo is actually the sensor mixing those bits together to render the color as it should be. The problem is that LED stage lighting is pure red, pure blue, etc, so you wind up 'losing' up to half to three quarters of the data you'd get under normal lighting, and you wind up with the results you see there. What you're describing is the Bayer filter. If that's the cause of the problem, having a CCD sensor won't help. Neither will having the K-5 IIs: the AA filter is supposed to prevent interference patterns between the Bayer filter and regular patterns in the subject. In the IIs, the AA filter is removed, but the Bayer filter is still there. AFAIK, there are only two sensor types which won't cause this problem. One is Sigma's Foveon sensors. They sense all three colors at every pixel, so no Bayer filter is needed. The other kind is a monochrome sensor, for obvious reasons.