Not accurate purple colors?

kenhreed · 02-12-2011, 08:11 PM

What would cause pictures taken of a dark purple flower to come out looking much more washed out than it actually was? DA70mm,K20D,no flash, taken in the shade.
Thanks,
Ken

JeffJS · 02-12-2011, 08:15 PM

Picture?

A lot of things can cause that, over exposure being one of them (among many other things).

kenhreed · 02-12-2011, 08:47 PM

kenhreed · 02-12-2011, 08:48 PM

Here's the picture, thanks in advance for any advice. Ken

**Just1MoreDave** · 02-12-2011, 09:02 PM

The two most likely problems are white balance and overexposure. EXIF should tell you what the white balance was, and you can tell if it was appropriate for shade.

Overexposure can shift colors because of the basic design of the sensor. It uses a Bayer filter. Look at the image on the right of this page:
Bayer filter - Wikipedia, the free encyclopedia

See how there's twice as many green dots as red or blue dots? As you increase exposure, red and blue pixels can get maxed out before green does. The overall meter and histogram doesn't show overexposure, but the camera can't record any more information in red or blue. If you increase exposure beyond that point, greens get brighter, but maxed out colors are stuck at the same level, so colors shift.

That's why your camera can display histograms for separate colors if you want. Flowers are a classic case for this issue, because they often have nearly solid reds, blues or in your case both, in a field of green. When you don't have histograms for separate colors, don't push the overall exposure histogram to the right edge. My guideline was to underexpose by 0.5 stop, which I just guessed at but seems to work.

**Just1MoreDave** · 02-12-2011, 09:07 PM

BTW, I figured this out pretty quickly when I started using RAW and Adobe Camera RAW for processing. ACR shows you right away when each color is overexposed, and you can move the exposure slider up and down to see the color shift. I saw a lot of blown reds at first. Only afterwards did I discover the theory.

JeffJS · 02-12-2011, 10:28 PM

You're saying those are washed out compared to what was really there? Another thing that can affect photos is your screen calibration. The photos (in your album) look out of focus and maybe a Touch overexposed, but I'm not seeing washed out purples.

Tell me, just for grins and giggles, how do these look on your screen?

kenhreed · 02-12-2011, 11:03 PM

Both of your samples look more purple than mine. My picture seems to be more pink than purple.

Hypocorism · 02-12-2011, 11:18 PM

Originally posted by kenhreed

What would cause pictures taken of a dark purple flower to come out looking much more washed out than it actually was? DA70mm,K20D,no flash, taken in the shade.

My guess is: That's what.

Cameras never see the intrinsic beauty of flowers like we do, so you have to give it a leg up. Subtle flash assistance.
For some reason that little bit of softened light, preferably coming from off centre if possible, works like magic to grab and highlight the amazing richness of the colours, shapes and textures that you already know is there, and naturally expect to be reproduced in your image.

That and making minor settings compensations like other posters suggest will be necessary too, same reason, also because the camera is a dumb object. It does its best.

.R.

"Please do not shoot the pianist. He is doing his best." -- Oscar Wilde 1854-1900)

JeffJS · 02-13-2011, 08:23 AM

Ok, I understand. I think you have a color balance and/or exposure problem. My experience with the K20d is that it's pretty accurate with colors once set properly.

kenhreed · 02-13-2011, 09:02 AM

Thanks to everyone. Next time would you suggest that I bracket my exposure to find out if that was my problem? Then either take it in RAW or change white balance to shade? (The flower is at my dad's house 2 hours away or I'd try it today.)

JeffJS · 02-13-2011, 02:52 PM

Bracketing can't hurt and I would be shooting RAW+ anyway. To keep things simple, only for compatibility reasons, you might want to use DNG rather than PEF.

02-12-2011, 08:11 PM	#1
kenhreed Senior Member Join Date: May 2009 Location: Sacramento Photos: Albums Posts: 131	Not accurate purple colors? What would cause pictures taken of a dark purple flower to come out looking much more washed out than it actually was? DA70mm,K20D,no flash, taken in the shade. Thanks, Ken

02-12-2011, 11:03 PM	#8
kenhreed Senior Member Join Date: May 2009 Location: Sacramento Photos: Albums Posts: 131 Original Poster	Purple flowers Both of your samples look more purple than mine. My picture seems to be more pink than purple.

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02-12-2011, 08:15 PM	#2
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Picture? A lot of things can cause that, over exposure being one of them (among many other things).

02-12-2011, 08:47 PM	#3
kenhreed Senior Member Join Date: May 2009 Location: Sacramento Photos: Albums Posts: 131 Original Poster

02-12-2011, 08:48 PM	#4
kenhreed Senior Member Join Date: May 2009 Location: Sacramento Photos: Albums Posts: 131 Original Poster	Here's the picture, thanks in advance for any advice. Ken

02-12-2011, 09:02 PM	#5
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	The two most likely problems are white balance and overexposure. EXIF should tell you what the white balance was, and you can tell if it was appropriate for shade. Overexposure can shift colors because of the basic design of the sensor. It uses a Bayer filter. Look at the image on the right of this page: Bayer filter - Wikipedia, the free encyclopedia See how there's twice as many green dots as red or blue dots? As you increase exposure, red and blue pixels can get maxed out before green does. The overall meter and histogram doesn't show overexposure, but the camera can't record any more information in red or blue. If you increase exposure beyond that point, greens get brighter, but maxed out colors are stuck at the same level, so colors shift. That's why your camera can display histograms for separate colors if you want. Flowers are a classic case for this issue, because they often have nearly solid reds, blues or in your case both, in a field of green. When you don't have histograms for separate colors, don't push the overall exposure histogram to the right edge. My guideline was to underexpose by 0.5 stop, which I just guessed at but seems to work.

02-12-2011, 09:07 PM	#6
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	BTW, I figured this out pretty quickly when I started using RAW and Adobe Camera RAW for processing. ACR shows you right away when each color is overexposed, and you can move the exposure slider up and down to see the color shift. I saw a lot of blown reds at first. Only afterwards did I discover the theory.

02-12-2011, 10:28 PM	#7
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	You're saying those are washed out compared to what was really there? Another thing that can affect photos is your screen calibration. The photos (in your album) look out of focus and maybe a Touch overexposed, but I'm not seeing washed out purples. Tell me, just for grins and giggles, how do these look on your screen?

02-12-2011, 11:18 PM	#9
Hypocorism Veteran Member Join Date: Sep 2010 Location: Melbourne .au Posts: 623	Originally posted by kenhreed What would cause pictures taken of a dark purple flower to come out looking much more washed out than it actually was? DA70mm,K20D,no flash, taken in the shade. My guess is: That's what. Cameras never see the intrinsic beauty of flowers like we do, so you have to give it a leg up. Subtle flash assistance. For some reason that little bit of softened light, preferably coming from off centre if possible, works like magic to grab and highlight the amazing richness of the colours, shapes and textures that *you* already know is there, and naturally expect to be reproduced in your image. That and making minor settings compensations like other posters suggest will be necessary too, same reason, also because the camera is a dumb object. It does its best. .R. "Please do not shoot the pianist. He is doing his best." -- Oscar Wilde 1854-1900)

02-13-2011, 08:23 AM	#10
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Ok, I understand. I think you have a color balance and/or exposure problem. My experience with the K20d is that it's pretty accurate with colors once set properly.

02-13-2011, 09:02 AM	#11
kenhreed Senior Member Join Date: May 2009 Location: Sacramento Photos: Albums Posts: 131 Original Poster	Thanks to everyone. Next time would you suggest that I bracket my exposure to find out if that was my problem? Then either take it in RAW or change white balance to shade? (The flower is at my dad's house 2 hours away or I'd try it today.)

02-13-2011, 02:52 PM	#12
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Bracketing can't hurt and I would be shooting RAW+ anyway. To keep things simple, only for compatibility reasons, you might want to use DNG rather than PEF.