Adjust color to compensate for 2700K

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tmcdanel
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Joined: Sat Dec 04, 2010 11:47 pm

Adjust color to compensate for 2700K

Post by tmcdanel »

I have pictures shot in a gym under sodium lights. These are about 2700 degrees K so they are very very warm and yellow. Fortunately i had the camera set to save both jpeg and .CR2 raw files. I attached a sample but i don't know if Yahoo groups allow such big files so here is a link to Dropbox.How do i adjust the color on the .CR2 file to make it look less yellow and more natural?Can i do this with batch processing?
Tony Jackson
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Joined: Wed Nov 03, 2010 11:36 am

Re: Adjust color to compensate for 2700K

Post by Tony Jackson »

On 21 May 2016, at 17:00, tmcdanel@fastmail.fm [gcmac] <gcmac@yahoogroups.com> wrote:I have pictures shot in a gym under sodium lights. These are about 2700 degrees K so they are very very warm and yellow. Fortunately i had the camera set to save both jpeg and .CR2 raw files. I attached a sample but i don't know if Yahoo groups allow such big files so here is a link to Dropbox.How do i adjust the color on the .CR2 file to make it look less yellow and more natural?Sodium light is of two frequencies only (and one of those is at much lower intensity than the other).  It is thus a *monochrome* light.  It used to be one of the most energy-efficient ways of making electric light, hence its widespread use in street lighting.  (Nowadays LED’s are more common).But it is of no use for colour photography of any kind.You might care to make it greyscale - your work would then look like a Black and White photo, perhaps?Best regards, T. Tony JacksonDevon, UK.
Al Treder
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Joined: Wed Jun 23, 2004 11:37 am

Re: Adjust color to compensate for 2700K

Post by Al Treder »

That’s good advice. One might also try a sepia tone filter, which we old-timers used to use to make B&W prints look more natural. Al“ No one is useless in this world who lightens the burden of it for anyone else. ”-- Charles Dickens On May 21, 2016, at 9:32 AM, Tony Jackson tony@you-me-and-us.com [gcmac] <gcmac@yahoogroups.com> wrote: On 21 May 2016, at 17:00, tmcdanel@fastmail.fm [gcmac] <gcmac@yahoogroups.com> wrote:I have pictures shot in a gym under sodium lights. These are about 2700 degrees K so they are very very warm and yellow. Fortunately i had the camera set to save both jpeg and .CR2 raw files. I attached a sample but i don't know if Yahoo groups allow such big files so here is a link to Dropbox.How do i adjust the color on the .CR2 file to make it look less yellow and more natural?Sodium light is of two frequencies only (and one of those is at much lower intensity than the other).  It is thus a *monochrome* light.  It used to be one of the most energy-efficient ways of making electric light, hence its widespread use in street lighting.  (Nowadays LED’s are more common).But it is of no use for colour photography of any kind.You might care to make it greyscale - your work would then look like a Black and White photo, perhaps?Best regards, T.Tony JacksonDevon, UK.
Al Treder
Posts: 0
Joined: Wed Jun 23, 2004 11:37 am

Re: Adjust color to compensate for 2700K

Post by Al Treder »

Addendum:The sodium vapor lamp illumination is so monochromatic that the only color in your image is yellow. It's either yellow or it's dark.The yellow is not just a color-cast, like you get from incandescent lighting, it's the only light. So, there is no way to find other colors in the image, and you may as well convert it to gray-scale, and then use a sepia filter if you like that effect.Al Treder -----Original Message----- From: "Al Treder altreder@earthlink.net [gcmac]" Sent: May 21, 2016 10:02 AM To: GraphicConverter Forum Subject: Re: [gcmac] Adjust color to compensate for 2700K   That’s good advice. One might also try a sepia tone filter, which we old-timers used to use to make B&W prints look more natural. Al“ No one is useless in this world who lightens the burden of it for anyone else. ”-- Charles Dickens On May 21, 2016, at 9:32 AM, Tony Jackson tony@you-me-and-us.com [gcmac] <gcmac@yahoogroups.com> wrote:On 21 May 2016, at 17:00, tmcdanel@fastmail.fm [gcmac] <gcmac@yahoogroups.com> wrote:I have pictures shot in a gym under sodium lights. These are about 2700 degrees K so they are very very warm and yellow. Fortunately i had the camera set to save both jpeg and .CR2 raw files. I attached a sample but i don't know if Yahoo groups allow such big files so here is a link to Dropbox.How do i adjust the color on the .CR2 file to make it look less yellow and more natural?Sodium light is of two frequencies only (and one of those is at much lower intensity than the other).  It is thus a *monochrome* light.  It used to be one of the most energy-efficient ways of making electric light, hence its widespread use in street lighting.  (Nowadays LED’s are more common).But it is of no use for colour photography of any kind.You might care to make it greyscale - your work would then look like a Black and White photo, perhaps?Best regards, T.Tony JacksonDevon, UK. Al Treder \r\G&C Engineer\Artistic Photographer\http://altreder.photoshelter.com\\altre ... thlink.net
thorstenlemke
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Joined: Fri Dec 30, 2016 12:00 pm

Re: Adjust color to compensate for 2700K

Post by thorstenlemke »

Hello,you can adjust the color temperature with Effect/Hot Cold.Thorsten I have pictures shot in a gym under sodium lights. These are about 2700 degrees K so they are very very warm and yellow. Fortunately i had the camera set to save both jpeg and .CR2 raw files. I attached a sample but i don't know if Yahoo groups allow such big files so here is a link to Dropbox.
Carl von Einem
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Joined: Mon Jul 23, 2012 12:58 pm

Re: Adjust color to compensate for 2700K

Post by Carl von Einem »

To me this looks like an environment with mixed light sources. Generally there are two types of sodium "bulbs", both emitting a different spectrum. Since I have some experience with the vast product range of a major brand for discharge / fluorescent / Halogen etc. lamps (for a couple of years I retouched or even composed product images for their packaging) I wouldn't be so sure about what type of lamps actually are installed in that gym. That said, your RAW images contain lots of different colors: a green lanyard, red basketball "ring", blue / green / orange / mauve scarves and other fabric. Also a wooden floor, and different types of skin colors. Far from monochrome. While color temperature is one aspect you'll also need to compensate for some heavy color casts. The best approach is to correct for these during development of your RAW files. Identify those regions you have an idea how they should look like in reality and have a look at the rgb values in bright, mid tone and dark areas. Compare with good looking examples in images that you already have. What kind of raw processor do you use? Maybe I can give you some hints where and how to tame all the skin tones etc. so you can batch "develop" these files yourself. Here is my quick result (with some over saturated blue and yellow tones), zipped JPG files plus metadata XMP from Adobe CS6 ACR: <https://www.dropbox.com/s/ev3iqnnpa7ecq ... s.zip?dl=0> Regards, Carl tmcdanel@fastmail.fm [gcmac] wrote on 21.05.16 18:00: > > I have pictures shot in a gym under sodium lights. These are about 2700 > degrees K so they are very very warm and yellow. Fortunately i had the > camera set to save both jpeg and .CR2 raw files. I attached a sample but > i don't know if Yahoo groups allow such big files so here is a link to > Dropbox > <https://www.dropbox.com/sh/0z57i31090u2 ... EfYta?dl=0>. > > How do i adjust the color on the .CR2 file to make it look less yellow > and more natural? > > Can i do this with batch processing? >
Al Treder
Posts: 0
Joined: Wed Jun 23, 2004 11:37 am

Re: Adjust color to compensate for 2700K

Post by Al Treder »

I think it was Dr. Edwin Land who proved you could reconstruct color of an image with two illumination frequencies, so if the scene was lit by bulbs with two sufficiently different (but still each monochrome and within the sensitivity of the sensor) frequencies, then there is color to be had. Sums and differences do the trick. So it can be worth trying to remove the color cast to see what’s left, which would be darker and weaker and noisy but could still be made pleasing. Al“ You are not mature until you expect the unexpected.”-- Chicago Tribune  On May 22, 2016, at 3:52 AM, Carl von Einem einem@gmx.de [gcmac] <gcmac@yahoogroups.com> wrote:To me this looks like an environment with mixed light sources. Generally there are two types of sodium "bulbs", both emitting a different spectrum. Since I have some experience with the vast product range of a major brand for discharge / fluorescent / Halogen etc. lamps (for a couple of years I retouched or even composed product images for their packaging) I wouldn't be so sure about what type of lamps actually are installed in that gym.That said, your RAW images contain lots of different colors: a green lanyard, red basketball "ring", blue / green / orange / mauve scarves and other fabric. Also a wooden floor, and different types of skin colors. Far from monochrome.While color temperature is one aspect you'll also need to compensate for some heavy color casts. The best approach is to correct for these during development of your RAW files. Identify those regions you have an idea how they should look like in reality and have a look at the rgb values in bright, mid tone and dark areas. Compare with good looking examples in images that you already have.What kind of raw processor do you use? Maybe I can give you some hints where and how to tame all the skin tones etc. so you can batch "develop" these files yourself.Here is my quick result (with some over saturated blue and yellow tones), zipped JPG files plus metadata XMP from Adobe CS6 ACR:<https://www.dropbox.com/s/ev3iqnnpa7ecq ... astmail.fm [gcmac] wrote on 21.05.16 18:00:>> I have pictures shot in a gym under sodium lights. These are about 2700> degrees K so they are very very warm and yellow. Fortunately i had the> camera set to save both jpeg and .CR2 raw files. I attached a sample but> i don't know if Yahoo groups allow such big files so here is a link to> Dropbox> <https://www.dropbox.com/sh/0z57i31090u2 ... EfYta?dl=0>.>> How do i adjust the color on the .CR2 file to make it look less yellow> and more natural?>> Can i do this with batch processing?>
eligurwayne
Posts: 1
Joined: Fri Dec 30, 2016 3:41 pm

Re: Adjust color to compensate for 2700K

Post by eligurwayne »

Yeah Edwin Land used Green and Red to reconstruct all colors..Why it did not t take off and become a true innovation IDK.Colorsync Utility 'used' to work in previous editions of Apple OS now it is sort of disabled -  can change all sorts of image parameters too. Black/white points; color temperature...color profiles etc..It was used to decode NASA images by me as well.  
tmcdanel
Posts: 0
Joined: Sat Dec 04, 2010 11:47 pm

Re: Adjust color to compensate for 2700K

Post by tmcdanel »

Wow! I learned so much from this thread. This room, the largest space in my school for major get togethers, has been driving me crazy all year because of the lighting. I struggled to find camera settings that would compensate, unsuccessfully and a professional photographer told me that RAW files could be adjusted in processing. The explanations regarding monochromatic light really helped me understand the physics of what was happening.Thorsten's suggestions of playing with the Hot Cold Effect helped me to understand what was happening in a very direct way. Thank you all so much for your generous time and expertise. GC is a great group of people.terry.
Hagen Henke
Posts: 7
Joined: Fri Dec 30, 2016 9:47 pm

Re: Adjust color to compensate for 2700K

Post by Hagen Henke »

Hello,professional photographers would use a flash and an f stop of 16 or higher with a standard time like 1/125sec. for pictures of people all more or less in the same distance to the camera. The high f stop value excludes the colored ambient light. Without the flash the picture would come out more or less all black. So the light in the picture is from the flash only and flashes produce light like sunlight at noon.For an overview picture this trick does not really work as light becomes less in a square formula: double distance means only a quarter of the light reaches the object so the flash would help only for the nearest objects. Play around a litte with lower f stop values and higher ISOs to get the ambient light for the background. The rest you do in GraphicConverter. Try also the Xe8472 from the filter menu.Regards, Hagen Henke ---Hagen HenkeDresdner Str. 2601662 Meia�enTel: 03521 / 71 77 494Mobil: 0151 / 524 789 21www.fotoservice-henke.de Am 25 May 2016 um 22:44 schrieb tmcdanel@fastmail.fm [gcmac] <gcmac@yahoogroups.com>:Wow! I learned so much from this thread. This room, the largest space in my school for major get togethers, has been driving me crazy all year because of the lighting. I struggled to find camera settings that would compensate, unsuccessfully and a professional photographer told me that RAW files could be adjusted in processing. The explanations regarding monochromatic light really helped me understand the physics of what was happening.Thorsten's suggestions of playing with the Hot Cold Effect helped me to understand what was happening in a very direct way. Thank you all so much for your generous time and expertise. GC is a great group of people.terry.
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