Visible twilight analogue using blue filter, I have realise…

I have realised that the transmission of a Cokin BLUE 80B photo-filter applied to the solar (outside the atmosphere) energy flux spectrum provides a remarkably good analogue for the colour of the twilight sky within the visible part of the spectrum. The plot shows a measurement of the twilight sky with a solar elevation of -8° (green line) compared with the Cokin-filtered intrinsic solar spectral energy distribution (blue line). The filter thus represents the the effect of the long atmospheric path taken by sunlight during twilight (The Blue Hour). There are differences in detail: the analogue is brighter than twilight in the far red (beyond about 680nm) and also peaks at a shorter wavelength in the blue, but is does provide a rather realistic twilight blue. The riboflavin fluorescence spectrum (red line) is of interest for animal vision but is incidental to this this post. Note: The slight wavelength shift between the two solar spectra is understood: I resampled the solar flux spectrum onto the original JAZ wavelength vector before I applied my calibration correction. This small difference is not important for this plot.

This Is Why You Should Appreciate the Cinematic Filmmaking of 'Twilight

Blue Hour Photography: The Definitive Guide

Pre-Owned 2022 GMC Sierra 3500HD Denali Ultimate Dually 6.6L Duramax Crew Cab Pickup in Edmonton #Z-U73064

Someone here made a post about how the blue filter would have looked on the other movies. I tried it out. : r/twilight

Make your Echo portable with a Battery Base. Designed to work with Echo (4th Gen). Echo sold separately. Enjoy your music away from the power outlet

Echo (4th Gen) | With premium sound, smart home hub, and Alexa | Twilight Blue

In-Depth: The Eerie Beauty Of The Apple Watch Solar Face, And The Anatomy Of Nightfall - Hodinkee

Sensors, Free Full-Text

Ready For Bed? How to Stop Blue Light From Disturbing Your Sleep

Why is looking at the sun during a solar eclipse worse than looking at the sun on a normal day? - Quora

Someone here made a post about how the blue filter would have looked on the other movies. I tried it out. : r/twilight

Orange/Blue Contrast - TV Tropes