2000K minimum colour temperature?

Is there any reason why 2000K is the minimum coolest temperature available on the ACR white balance selector? Wikipedia list match flame at 1700, and candle-light at 1850K.
I've taken some photos under a railway bridge with very dim sodium lights, and the grey pavement came up around 2000K +1 with the ACR white balance selector. I'm wondering if in fact a cooler temperature might be more accurate, and why it's not possible to go below 2000.

>Is there any reason why 2000K is the minimum coolest temperature available on the ACR white balance selector? Wikipedia list match flame at 1700, and candle-light at 1850K.
If you took a picture under candle light or a match flame, you probably would want to keep a reddish cast rather than balancing all the way to white. 2000K is usually sufficient for most conditions. If you want complete control over WB, try DCRaw, which allows you to seet the white balance multipliers manually.
>I've taken some photos under a railway bridge with very dim sodium lights, and the grey pavement came up around 2000K +1 with the ACR white balance selector. I'm wondering if in fact a cooler temperature might be more accurate, and why it's not possible to go below 2000.
Sodium lights come in two flavors: high pressure and low pressure. Low pressure sodium lamps were introduced in the 1930's and have a tubular shape, resembling florescent lights. There is a picture of a low pressure lamp in the link. Such lamps are often found in viaducts and under bridges. They emit essentially monochromatic light and are not suitable for color photography.
The high pressure lamps are more recent and resemble an incandescent bulb. Like Ann said they have a discontinuous spectrum (shown in the Wikipedia link) and a low color rendering index, but you might be able to coax come color out of the picture.

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Misteriously Colour Temperature change from my computer to others

Ok, I've been stuck with this strange problem now. Out of the blue it started happening and realised when I uploaded some pictures on Flickr. I open my NEF file (from Lightroom) as a Smart Object and start working upon it as normal. I move it to 8 bits when finished the first steps, save as a JPEG. Close the TIFF, open the JPEG, change a couple of things as some of my filters only allow me to work JPEG (at least they are always disabled otherwise). And save again. IF I open it up from my computer, the colours are ok. Whenever I upload to Flickr OR Facebook, OR email them to anyone, the colours change. Specially the temperature. And no, it's not the monitor because I can see them on Flickr with a different colour from my very own computer.
My basic workflow is as follows:
Lighrtoom 2.4 => [Open as .NET smart object into CS4] => CS4 Camera RAW [Adjust Colour Temperature, Saturation, Contrast, Vibration, etc, click ok, open all adjusted on CS4 Again] => Filters adjust [Topaz Adjust, Sometimes Noisewaire or Portraiture, Nik Colour Effect (I GUESS here is the problem but not sure).
When done with this first set, I change the picture from a 16bits format into a bits image in order to save as a JPEG. => [Save as] > .JPEG 12 (Minimum compression). I then close the open TIFF image and open the respective .JPEG image. All colours are exactly as I saved. All the same. I work upon a couple of more things (such as LUCISAR SE, for instance, smoothly). Save again. And that's it.
I found an answer in stuckincustoms.com. He had the same problem and found the answer in correctly Colour Settings:
[EDIT]=> [COLOUR SETTINGS] // Then select [Colour Management Policies] and move RGB to 'Convert to working RGB', all other 2 as OFF and click on 3 icons underneath. Save as a new file, close it all. Send. This seems to work sometimes, but not always. I'm not sure if it's the 'Nik Software Colour Effect' which is not holding...
Here are two links as an example. The first one is with the right colour settings. I've done what Ratcliff told. The second one 'cooled down', even so I did what he told me to. I mean, same workflow both, different results.
http://photos-a.ak.fbcdn.net/hphotos-ak-snc1/hs244.snc1/9122_147658726621_505071621_276412 0_283341_n.jpg
http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs264.snc1/9122_147646046621_505071621_276406 8_6740954_n.jpg
You can see all my latest Flickr pictures have got the same problem. Some look nice, BUT it was not as I had edited.
http://www.flickr.com/lteles
HOW do I correct this??? And most importantly: WHY is this hapening?
Thanks,
Regards,
Leo

What do you mean "it dropped during transition." If you are maintaining temperature at some level, then the transition should have no affect on the temperature unless you reinitialize or have wired a default number to the temperature you are trying to control. I tried loading your program. I don't have the instrument controls for the instrument you are using -- not a problem -- but it is hard to follow what you are doing. It looks like you have many different setpoints all coming from the ni435x read.vi in a 2d array. You should check that the values you expect out of that array are correct for each of the points that you use it.
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Thunderbolt display changes colour temperature when in full screen mode

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I describe my problem here. I think it's similar, can you see if the console gives you the same error?
https://discussions.apple.com/message/20162986#20162986

Minimum Operating Temperature?

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Adjusting brightness and colour temperature on WindowXP PC

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I'm using Windows XP PC. I just bought 27" Cinema Display but I find that i can't adjust brightness and colour temperature in Windows XP......
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For brightness you need the AppleControlPanel.exe file from the Boot Camp package to be able to adjust the brightness - don't install the whole of Boot Camp as it will cause problems on a non-Apple PC, just get this one file - I can provide it if you can't find it elsewhere.

White balance, colour temperature value.

Hi all,
I've spent some time recently looking at the temperature value in the white balance adjustment for a selection of my pictures in Aperture.
All of my pictures are taken outdoors in natural daylight. I've noticed the colour value of my RAW pictures in Aperture varies. Is this value recorded by the camera when it takes the picture or is it a value that Aperture works out depending on the colours it sees in the picture?
For example for one set of outdoor pictures I took in the space of about 30mins the temperature value varies from 4685K to over 5000K and yet as I remember the apparent ambient temperature and light didn't change.
I usually have the white balance on my camera set to auto but am I correct in thinking that since I shoot in RAW mode the white balance setting will have no affect on the RAW file produced and will only affect the accompanying jpeg? Or is the current white balance setting recorded to the RAW file but without adjusting the picture data and this is the value we see as the temperature in Aperture? Hence if I've got the camera set to auto WB and one moment the camera thinks it's sunny when I take a picture and the next time it thinks it's cloudy then the raw files are recorded with a different colour temperature?
Regards,
Dave.

You have almost got it correct.
Jpeg will have the WB as per the camera setting.
The raw file does not have a WB setting. Aperture makes a rough assessment in much the same way your camera does.
Nothing gets recorded to the raw file only the information from sensor.
In camera, to produce the jpeg, the processor looks at blocks of data & applies an average value to the block. Lets say there is a block of 8 pixels with 8 different values, the jpeg file format gives it 1. So were you had 8 shades in the raw file you now have one in the jpeg.
Unless you have a specific need to import both, Aperture can make all the jpegs you want, any size and better quality and easier than you can in camera.

White balance doesn't match CR2 EXIF colour temperature after import?

Why does Lightroom make it's own choice of white balance for "as shot"?
My CR2s from both a 40D and previous 350D all exhibit a shift in colour temperature compared to the EXIF data. It's not even consistent and a sequence of shots can visibly differ.
I know that camera auto white balance has its issues, but it does look like the camera makes a better initial guess than LR....
Thanks,
Barrie

The numbers are dependent on the mathematical model used to model the distribution of wavelengths in the lightsource. The details are rather heady, but indeed, the black body temperature is not as well defined as you might think. This is because a lightsource is seldom an actual black body radiator (not even the sun is due to atmospheric absorption, diffuse scattering on dust particles, and Raleigh scattering on the air molecules). If it were you would not need the "tint" number to describe it. There are quite a few different models for this in use and so it is not strange to see different numbers for the same conditions. In ACR/lightroom they are even dependent on the camera profile if I understand this correctly. Bottom line is that what is neutral in the camera system is neutral in the ACR/Lightroom number system. That's all you need to know.

ACR colour temperature changes not honoured

Using Win7 64bit, CS6 perpetual with xmp files as sidecars, I have made droplets that will open a nef file and run various processes before saving the file.
I have recently seen an issue where the droplet will not honour any colour temperature change I make in ACR (using 2010 profile).
If I have a batch of images shot together I would normally select one image, adjust colour temperature (say -500) and click "Done" to save the changes. I would then select the remaining images in that batch (in Bridge) and apply the changes via delevop settings, pervious conversion. The thumbnails in Bridge then get updated to reflect this change.
If I drop this folder on the droplet, the first image processed wil be the colour I require while the remainder will revert to "as shot" colour.
If I open any of the "incorrectly processed" raw files on their own (without making any changes tot he ACR settings) and run the same action from the action action palette, the colour change I have made is honoured.
Any ideas as to why this may happen? I am not aware of any changes I have made that would cause this.
Thanks for any help.
Dave

kbtan wrote:
Hi guys, this thread seems to solved my MBP's problem:
http://forums.macrumors.com/showthread.php?t=1392978
http://www.macrumors.com/2012/07/10/gfxcardstatus-allows-easy-control-of-macbook -pro-graphics-cards/
gfxCardStatus by Cody Krieger: http://codykrieger.com/gfxCardStatus
Preventing the MacBook from dynamically switching from integrated (not blue) to discrete (blue) is not really suitable for me. What is posted in above links are only workarounds that limit the functionailty of my device. I want to use the features of my Mac as intended by Apple to preserve battery life. I want both display drivers to show the same colour.
PRAM reset never worked for me.
Booting Mac, logging in then off and on again is also a workaround -- I think mentioned here somewhere previously. This is a major pain though, as you can imagine.
Thanks for drawing my attention to display mode switching as being the potential cause however.

Importance of precise colour temperature when creating dual-illuminant DNG profile

I own an X-Rite ColorChecker Passport and would like to use it to create a dual-illuminant profile for my camera (and every lens combination) to use in LightRoom.
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2)      If I don’t nail it down that precisely, will the resulting profile be any less accurate?
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4)      If it will really aid profile accuracy, how does one get hold of reliable/certified light bulbs that produce the required colour temperatures? (I’m in the UK)
Your advice will be greatly appreciated.

The exact color temperatures (in Kelvin) are not that important within the standard daylight range (above 4000 K), because large number changes in color temperature actually represent small differences as far as camera color profiles go.
What is more important (rather than the exact number) is the spectral characteristics of the illumination. This isn't easy to characterize for the end user, but you can think of it in terms of bulb type. Most compact fluorescents are spectrally very different from actual daylight (even if the bulb is indicated as being "full spectrum"), for instance. My recommendation is to create a profile for the type of lighting you will be under, rather than trying to match the exact numbers.

How do I stop Acrobat changing the colour temperature of my 24" LED display

When I run an Acrobat in full screen mobe on my MacBook Pro connected to my 24" LED Cinema display it changes the colour temperature of the screen making it overly warm. The only way to rectify this is to go into system settings > displays > colour and select my callibrated profile.
Does anyone have the same problem or a fix?
Model Name:    MacBook Pro
Model Identifier:    MacBookPro5,1
Processor Name:    Intel Core 2 Duo
Processor Speed:    2.8 GHz
Number Of Processors:    1
Total Number Of Cores:    2
L2 Cache:    6 MB
Memory:    4 GB
Bus Speed:    1.07 GHz
Boot ROM Version:    MBP51.007E.B05
SMC Version (system):    1.33f8

I am having a similar problem that I just began noticing. When I go to Full Screen mode my display darkens, and I have to go to the color settings in my display preferences to reset it. It is very dark. I have only noticed this in the last week or so. I thought it was related to hooking up to a digital projector, but it happens whether I am hooked up to an external display or not.
The only other thing that happened in the last couple of weeks was a software update, and I am convinced it is a software problem isolated to Acrobat Pro 9.3.4. If I open a file in Adobe Reader 9.2.0 and go to full screen mode everything is fine.
I am also working on a MacBook Pro.
Model Name:    MacBook Pro
Model Identifier:    MacBookPro5,4
Processor Name:    Intel Core 2 Duo
Processor Speed:    2.53 GHz
Number Of Processors:    1
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L2 Cache:    3 MB
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This is really irritating, because it darkens images to the point that the details in photos are lost.

Colour Temperature

In Photoshops's RAW Converter there is a slider which allow you to correct white balancing/colour temperature problems. Is there such a function in Photoshop that can perform the same alteration (simple easy) on a JPG image? Colour Balance is too long winded for a simple colour temperature alteration.
Thanks

Dougnik12 wrote:
In Photoshops's RAW Converter there is a slider which allow you to correct white balancing/colour temperature problems. Is there such a function in Photoshop that can perform the same alteration (simple easy) on a JPG image? Colour Balance is too long winded for a simple colour temperature alteration.
Thanks
Adobe Camera Raw can be used on JPGs as well as raw files. The topic is well covered in Photoshop Help: search "open JPEG camera raw". The easiest way to do so is to select the JPGs to be edited in ACR and then press CRTL+R (windows) or CMD+R (Mac).
Since you have only 8 bits with which to work with JPEGs, you may encounter problems when a large color shift is needed.

Fine Colour Temperature Adjustments

When using the Adjustment Brush and the Graduated Filter in Lightroom 5, I only on occasion am given the colour temperature option in the drop-down menu. This is posing quite the problem in making specific adjustments to mixed-light situations. I never seem to have the option for CR2, or DNG, it is only there on occasion for JPG. Is there a problem with my settings that is causing this restiriction?
Thank you!!

Maybe you have your Process Version set to 2003 or 2010. The color temperature sliders are only available in PV2012 for the Adjustment Brush and Graduated Filter.

WB colour temperature

I am calibrating my Pentax 10D with your raw dng profile editor.
I shot two DNG images of CC one in direct sun and the other with tungsten filament lamps.
Checking with camera raw (4.6-CS3) the color temp of white patches were 5350 and 2600. So far so good. To me these seem ok.
On opening with DNG profile editor and setting colour balance the values obtained were 6950 and 4000. Hmpf
I continued to make profile and exported profile for use in lightroom (2.2)
Using new profile and "as shot" pictures appears colour balanced.
If I change to another profile say adobe standard or other also using "as shot" the pictures remains colour balanced but the colour temp reduces by around 150K. the same difference as found above.
Basically my new profile raises the indicated WB temp conciderably.
Can someone help here, surely the "as shot" should be independent of profile?
Roger

Problem solved.
If I update DNG files from camera with camera raw (gaining a base profile)then profile editor WB operates as it should.
Resultant profile also ok.
Roger

Screen colour temperature changes (bluer) when running web video, iDVD

An odd intermittent issue I noticed since upgrade from Lion to Mountain Lion.
Noticed on MacBook Pro 15" (high resolution), Early 2011 (MacBookPro8,2).
When I launch iDVD the screen turns brighter and a more blue-ish hue. It reverts when I close iDVD.
Issue is not isolatied to iDVD, for example it also occurs when running BBC Olympics web video content:
http://www.bbc.co.uk/sport/olympics/2012/live-video/bbc_one_2012_hd
Anyone know the cause or have a workaround? Driving me crazy!

kbtan wrote:
Hi guys, this thread seems to solved my MBP's problem:
http://forums.macrumors.com/showthread.php?t=1392978
http://www.macrumors.com/2012/07/10/gfxcardstatus-allows-easy-control-of-macbook -pro-graphics-cards/
gfxCardStatus by Cody Krieger: http://codykrieger.com/gfxCardStatus
Preventing the MacBook from dynamically switching from integrated (not blue) to discrete (blue) is not really suitable for me. What is posted in above links are only workarounds that limit the functionailty of my device. I want to use the features of my Mac as intended by Apple to preserve battery life. I want both display drivers to show the same colour.
PRAM reset never worked for me.
Booting Mac, logging in then off and on again is also a workaround -- I think mentioned here somewhere previously. This is a major pain though, as you can imagine.
Thanks for drawing my attention to display mode switching as being the potential cause however.

Changing Colour Display for Temperature Distribution

Hi everyone,
I am currently involved in reading a series of temperatures along a length of pipe as part of an experiment. I thought it would be a nice touch for my VI to have a diagram of the pipe which changes colour to show the temperature distribution along it.
I have attached my initial solution. I would have posted a VI snippet but this seemed to effect the my references in the property nodes.
Issues
The code 'works' in the sense that the foreground colour of each tab control will change based on the value of the corresponding temperature.
The solution does not scale well. I need 'n-1' case structures for 'n' colours/temperatures. I considered using an enum input to a single case structure, but was not sure how to compare this to the for loop index.
Unsure whether changing a tab control background is the most efficient way to do this. Not sure of an alternative.
I am looking for suggestions as to how to do this more efficiently as there will be up to 16 temperatures in the final system.
Many thanks in advance,
Pete
Regards,
Peter D
Attachments:
Temperature Display.vi ‏16 KB

Tabs are probably the weirdest choice here. Why not use e.g. a simple colorbox or button?
In any case, try to learn about autoindexing, it will dramatically simplify your code (see attached in yellow box).
I probably would use an array of clusters, each containing a colorbox and a numeric with transparent background. Modify as needed. (see attached in green box).
Of course you probably would want to make it a it prettier than my draft.
For a larger ramp, I would use a plain array of flat colorboxes. Now simply index into a color ramp to generate it according to your temperatures.
LabVIEW Champion . Do more with less code and in less time .
Attachments:
Temperature DisplayMOD.vi ‏18 KB

2000K minimum colour temperature?

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