How does being in a polar region affect the golden and blue hours of light?

Question

While I already know what the golden and blue hour are, I am having trouble understanding how this changes very close to the poles so that I can time an upcoming trip to Iceland.

Online services give different interpretations which make little sense. Here is a screencap from Twilight Calculator. Note how the sunset and sunrise time increase consistently and so does the corresponding Golden hour and Twighlight duration until May 16th. On May 17th things get weird. The golden hour duration jumps from 122 mins the previous day to 309 mins. 309 mins!

• Does that mean the sun stays above the horizon the whole night? In which case, it should be all golden and none blue.
• Or does the sun dip below the horizon? As suggested by the fact there there is a sunset and sunrise time and therefore. And therefore should there not be about 305 mins of blue hour? ...and the golden hour should last about 87 mins?
• Should the last two columns in that chart be reversed starting on May 17th?

Given that I am looking to Iceland for mostly landscape shooting, the big question is: When would there be the most golden light? (So when the sun is above the horizon and not below).

Asked by Itai

Answer

Iceland is so far north that depending where you are in the country, you get significantly different results. Compare the following chart from gaisma.com for Reykjavík, which is in the south:

With this chart, for Ísafjörður in the north:

As you can see, between mid June and the beginning of July, the sun never actually sets in the north of Iceland, however in Reykjavík it DOES set, but it stays light enough to remain twilight throughout sundown (the pink area). At this latitude, there would be little to no 'blue hour' as it rarely gets dark enough, even in Reykjavík.

To answer your final question, the best time to go for as much golden hour as possible would be between mid May and late July, as this is when you get the most twilight (as much as 5 hours), and as it occurs in the early hours of the morning, you will not be competing with tourists for the best scenes.

Note that as Iceland is not on the meridian, but uses GMT throughout the year, the sun's lowest point occurs at around 1:30 am, not midnight, so you can still get 'midnight sun' in Reykjavík around the summer solstice, even though the sun does eventually set (around 12:05 am).

Oh, and have a great time. Iceland is a wonderful country!

Answered by Nick Miners

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