Color Temperature at sunrise and sunset...

Apr 29, 2017,06:32 AM
 

Based on a discussion some weeks ago about the difference between photographing sunrise and sunset, I have been recording the color temperature changes... and learning to enjoy waking up early...  today was a unique day in the on going test... there were clear skies at 4:51 AM and 18:20 PM... let's take a look.





After sunset looking north

To be correct color temperature measurements are in Kelvin and like other aspects of photography the logic is reversed...  larger Kelvin values are cool and low Kelvin values are warm...

Color temperatures over 5000 K are blue-white and referred to as "cool colors"
Color temperatures (2700–3000 K) are yellow-white and called "warm colors"
Vertical daylight and electronic flash are considered to be 5500 K

The testing is still in process, but here are the results from today...



In general, during sunrise the color temperature gets progressively warmer while at sunset the color temperature gets progressively cooler... and typically the change is more pronounced at sunset... it's a little counter intuitive as we normally have red & orange sunsets... that quickly turn bluish as the sun dips below the horizon.

Here are the actual measurements from today (29-April-2017)...



The "mired" is a unit of measure along the Blue & Amber axis and indicates how strong a warming or cooling filter needs to be to keep the same or a reference white balance... (1,000,000/Kelvin=Mired).  In the case of sunrise we would need a progressively darker blue filter while at sunset a progressively warmer filter would be required.  If shooting daylight film the reference is 5500 K or 182 Mired.

CC (Color Correction) is a measurement along the Magenta & Green axis.  Sunrise is fairly stable while we see a variation at sunset.

The test is on going... and so far I have managed to struggle to the balcony at 4:45 AM...

Casey

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Comments: view entire thread

 

The photo is incredible Casey.....

 
 By: watercolors : April 29th, 2017-12:14
There is a website called time and date . c o m where you have calculations on sunrises/sunsets as well as the angle of the sun in % above/below horizon for your location on a given day etc. This suggestion may help with details of your current project as... 

Thank you Edward...

 
 By: cshimokita : April 29th, 2017-13:28
Good suggestion... I am using that site... looking east is the Pacific Ocean so the times and location are accurate, I adjust the sunset details by about five minutes for the mountains west of Tokyo. ...  

For example in addition to the times ( -15,+15 minutes) on your graph you can add .....

 
 By: watercolors : April 29th, 2017-14:07
the angle of the sun above/below the horizon. Then the reader could visualize the changing amount of light at your location . Best Regards Edward

It might make sense to add that info to the final 'report'

 
 By: cshimokita : April 29th, 2017-14:41
or at least look at the data in that context to see any relevance. It is surprising how fast the sun moves at (e.g.) this time of year and this latitude...

Yes...

 
 By: watercolors : April 29th, 2017-15:04
for each twilight there are certain degrees that the sun is below horizon, I wonder how does that phenomenon affect color temperature if the flash is not used at all. It is basically going the opposite way from the moment of sunrise/sunset. Best Regards E... 

; )

 
 By: cshimokita : April 29th, 2017-15:20
[nt]

For example it the sunrise is at 6.19 am today for London, Ontario....

 
 By: watercolors : April 30th, 2017-01:35
and the Civil Twilight is from 5.48 am to the moment of sunrise and when there are no clouds, I believe the Color Temperature will be the same during the entire time. Civil twilight starts when the sun is raising at 6 degrees below the horizon in the morn... 

Great shot,

 
 By: InHavenPro : April 29th, 2017-13:19
interesting data sets. Not sure if I would have the desire to delve so deeply into it myself but I certainly greatly appreciate having somebody like yourself to share it here with us . I'll definitely keep reading! Cheers, Filip

LOL... I hear you Filip

 
 By: cshimokita : April 29th, 2017-13:42
I have learned that my balcony faces 90° East and 270° West is visible off the external stairs ; ) Since the tall buildings of Shinjuku are exactly 90° East... the sunrise will be perfectly positioned on 25-September-2017 and 19-March-2018 ... hahaha

XD [nt]

 
 By: InHavenPro : April 29th, 2017-13:50

I learned something new today...

 
 By: cshimokita : April 29th, 2017-14:04
and a word I haven't seen used in a long time: guffawing

Lol...

 
 By: watercolors : April 29th, 2017-14:08
I am laughing with you guys... but with eyes open wide. Best Regards Edward

Technicals aside....

 
 By: KamalRostov : April 30th, 2017-02:35
that is one beautiful color palatte!

Photographs of clouds have an interesting history...

 
 By: cshimokita : April 30th, 2017-05:57
"Equivalents" is a series of cloud photographs by Alfred Stieglitz taken between 1925-1934 and are considered to be some of the first abstract photographs. In the mid 1920s the Museum of Fine Arts in Boston acquired a number of cloud prints made by Stiegl... 

Thanks for the added info Casey :)

 
 By: KamalRostov : April 30th, 2017-08:14
I'm still learning the ropes with my camera and your photos have been my 'teacher'. I always look forward to your postings and photos. Thank you!

; ) ; )

 
 By: cshimokita : April 30th, 2017-13:21
[nt]