what exactly are Crepuscular Rays

[shimokita]

Crepuscular Rays can be defined as "rays of sunlight, which stream through gaps in [e.g. stratocumulus] clouds or between other objects" and/or "...columns of sunlit air separated by darker cloud-shadowed regions."

Crepuscular is strictly defined as: "of, pertaining to, or resembling twilight; dim; indistinct".

Thus at first flush it would seem that crepuscular rays would only be present when the sun is below the horizon, either from daybreak to sunrise or from sunset to nightfall... and thus limited to an atmospheric phenomenon as shown below.

I am not an English language expert, nor "strict" in any academic sense... however a friend used "Crepuscular Rays" when describing a photo with sun filtering through a forest valley (i.e. late afternoon) where I might use the (non-technical term) 'sunbeams'...

1) Is there a technical term for what I describe as sunbeams in the example above?

2) Are Crepuscular Rays limited to being 'twilight' atmospheric phenomena?

Casey

 

[lynnb]

It seems the definition depends on usage; either biological where it means around dawn or dusk, or atmospheric - where your friend's description might fit.

 

[Chris Bail]

Sunbeams are crepuscular rays. Light filtering through a forest are as well. Interestingly, anticrepuscular rays are opposite when the rays travel all the way to the other horizon and seem to converge. That's what the photo above looks like to me. Was the sun behind the camera in this photo?

 

[Chris Bail]

Crepuscular Rays are named as such because they often appear around twilight, but they don't necessarily need to occur at that time.

 

[sleepyhead]

I don't know, but I like this photo! I think if the foreground were lightened up a bit while keeping the sky as it is, it would be really super.

Crepuscular Rays can be defined as "rays of sunlight, which stream through gaps in [e.g. stratocumulus] clouds or between other objects" and/or "...columns of sunlit air separated by darker cloud-shadowed regions."

Crepuscular is strictly defined as: "of, pertaining to, or resembling twilight; dim; indistinct".

Thus at first flush it would seem that crepuscular rays would only be present when the sun is below the horizon, either from daybreak to sunrise or from sunset to nightfall... and thus limited to an atmospheric phenomenon as shown below.

I am not an English language expert, nor "strict" in any academic sense... however a friend used "Crepuscular Rays" when describing a photo with sun filtering through a forest valley (i.e. late afternoon) where I might use the (non-technical term) 'sunbeams'...

1) Is there a technical term for what I describe as sunbeams in the example above?

2) Are Crepuscular Rays limited to being 'twilight' atmospheric phenomena?

Casey

 

[shimokita]

... depends on usage; either biological... or atmospheric

Context is everything... thanks for the comment

Casey

 

[shimokita]

Was the sun behind the camera in this photo?

absolutely... an evening photo looking toward Shinjuku with the sun at my back

...and the original photo is an example of Devil's Rays.... bwahahahaha

 

[shimokita]

I don't know, but I like this photo! I think if the foreground were lightened up a bit while keeping the sky as it is, it would be really super.

Thanks sleepyhead... I did shoot a few, some with a lighter foreground... personal choice here, I wanted to eliminate detail and emphasize the sky... I'll take a look at the other shots and/or post processing options...

Casey

 

[MrFujicaman]

Also known as "god beams"

 

[John E Earley]

They were named after Ray Crepuscle, a bus driver from New Jersey who made a series of Polaroid shots of them.

 

[shimokita]

"Le Crépuscule des aigles" available in blu-RAY

George Peppard (Acteur, Réalisateur)
James Mason (Acteur, Réalisateur)
John Guillermin (Réalisateur)