Night mode might be as bad as blue light - Page 3

gaudi3 · 01-12-2020, 06:46 PM

Unfortunately, I don't have access to Kindle with front light. My Kindle DXG is without front light.

I'm also sorry about the little mistake. The color temperature dropped to 3300K and then started to rise.

Here are the detailed results with rounding to 100K and 100lx:

17:08 10200lx 3800K flicker 0.1%
17:15 8900lx 3500K flicker 0.1%
17:27 5800lx 3300K flicker 0.1%
17:30 4400lx 3500K flicker 0.2%
17:36 2700lx 3700K flicker 0.3%
17:40 1800lx 4300K flicker 0.4%

The test was related to the calibration of the meter for the sun, which is completely flicker-free. No meter is perfect and the flicker error increases as the level of illumination decreases. Thanks to this measurement, I know that if I want to build LED-based artificial lighting and measure a flicker of no more than 0.1%, I have to test at least 5000lx.

A few remarks:
1) The measurement was taken from a hill with a clear horizon over which the sun was setting.
2. the day was completely cloudless.
3) All the time the meter was directed towards the setting sun. Slight correction of the direction and the color temperature of the light rose dramatically.

Now, the most important thing: a person does not look directly at the sun as my meter does. Therefore, the color temperature that reaches the eyes is probably in the range of 4000K and higher. It is important that the spectrum of light is fairly even without any hills around the blue colour and maximally diffused, just as the blue sky diffuses light.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Kobo - Night light doesn't turn off in sleep mode	voidIndigo	Devices	3	06-05-2017 02:08 PM
Glo Blue light/Comfort light/eyestrain, etc.	oj829	Kobo Reader	4	09-01-2016 09:04 PM
Glo Night mode ?	Ethanaul	Kobo Reader	1	07-23-2013 10:23 PM
Is there a night mode?	zeroh	Nook Color & Nook Tablet	5	12-04-2010 10:24 AM
Ended Blue PRS-505 mint condition, Sapphire blue M-Edge cover and Kandle light (black) $150	Waba	Flea Market	4	11-06-2010 11:03 PM

01-12-2020, 06:46 PM	#31
gaudi3 Junior Member Posts: 8 Karma: 10 Join Date: May 2011 Location: Europe Device: Kindle DXG, My wish: Dasung monitor 13.3" My dream: Dasung monitor 32"	Unfortunately, I don't have access to Kindle with front light. My Kindle DXG is without front light. I'm also sorry about the little mistake. The color temperature dropped to 3300K and then started to rise. Here are the detailed results with rounding to 100K and 100lx: 17:08 10200lx 3800K flicker 0.1% 17:15 8900lx 3500K flicker 0.1% 17:27 5800lx 3300K flicker 0.1% 17:30 4400lx 3500K flicker 0.2% 17:36 2700lx 3700K flicker 0.3% 17:40 1800lx 4300K flicker 0.4% The test was related to the calibration of the meter for the sun, which is completely flicker-free. No meter is perfect and the flicker error increases as the level of illumination decreases. Thanks to this measurement, I know that if I want to build LED-based artificial lighting and measure a flicker of no more than 0.1%, I have to test at least 5000lx. A few remarks: 1) The measurement was taken from a hill with a clear horizon over which the sun was setting. 2. the day was completely cloudless. 3) All the time the meter was directed towards the setting sun. Slight correction of the direction and the color temperature of the light rose dramatically. Now, the most important thing: a person does not look directly at the sun as my meter does. Therefore, the color temperature that reaches the eyes is probably in the range of 4000K and higher. It is important that the spectrum of light is fairly even without any hills around the blue colour and maximally diffused, just as the blue sky diffuses light.