Why are exposure times so long if light travels so fast?

[TCampbell]

So Cal is not always 75 degrees, warm beach, and fake boobs. We have huge national forests that are completely untouched. My home studio is a short 15 mins drive to San Bernardino National forest. I go deer hunting there every year, 2am in the morning pitch black sitting on my tree standk, looking up to the beautiful sky with no major towns within 30 miles. I've never been able to see the Milky Way the way that my camera does.

The San Bernadino Natl Forest has Bortle 5-6 skies (if you use the color zones then it's mostly an "orange" zone and "yellow" zone.

I've been sailing up the North Channel of Lake Huron... these are Bortle 7-8 skies ("black" zone). It makes a HUGE difference!

On a moonless night with Bortle 7-8 skies... the Milky Way jumps off the sky at you and looks like a photograph. Your eyes absolutely see what you see in those long exposure photos. Your eyes must be dark-adapted (if you've switched on a lightbulb in the last 30 minutes... you're going to have to wait a while before your eyes adjust.) Eyes can mostly dark-adapt in about 20 minutes... but it takes closer to 40 minutes to be fully dark-adapted. Switching on a light for just a moment destroys the dark-adaption and you have to wait again.

 

[runnah]

Like they say at an Appalachian key party, it's all relative.

 

[Vtec44]

I guess I'll have to take your words for it... since I haven't been able to see it in person

 

[480sparky41 40]

The San Bernadino Natl Forest has Bortle 5-6 skies (if you use the color zones then it's mostly an "orange" zone and "yellow" zone.

I've been sailing up the North Channel of Lake Huron... these are Bortle 7-8 skies ("black" zone). It makes a HUGE difference!

On a moonless night with Bortle 7-8 skies... the Milky Way jumps off the sky at you and looks like a photograph. Your eyes absolutely see what you see in those long exposure photos. Your eyes must be dark-adapted (if you've switched on a lightbulb in the last 30 minutes... you're going to have to wait a while before your eyes adjust.) Eyes can mostly dark-adapt in about 20 minutes... but it takes closer to 40 minutes to be fully dark-adapted. Switching on a light for just a moment destroys the dark-adaption and you have to wait again.

Methinks you have your scale backwards.

 

[qleak]

Methinks you have your scale backwards.

He's referring to naked eye limiting magnitude (the NELM column):

Bortle scale - Wikipedia, the free encyclopedia

 

[480sparky41 40]

Methinks you have your scale backwards.

He's referring to naked eye limiting magnitude (the NELM column):

Bortle scale - Wikipedia, the free encyclopedia

Which is 'reversed' compared to the (referred-to) Bortle scale.

 

[Designer]

Not to be-labor the freakin' point, but we lived about 15 miles from any sizable town, and aside from our own freakin' yard light, there was no freakin' light. just look up and see the freakin' Milky Way.

 

[photoguy99]

Nerd.

 

[Trever1t]

best thread this month. gotta be some good hooch, that's all I'm sayin'

 

[Designer]

three glasses of wine with supper

 

[Designer]

I'd better not post the one I had written.

 

[DrDave]

...Time for a beer.

 

[Designer]

...Time for a beer.

Right.

I had a beer before supper.

 

[Light Guru]

Say, we've got a scene (hipothetically) with NOTHING moving in it and no more or less light entering it, it's stagnant. How would it make a difference in the final picture if I left the shutter open for 1/1000 of a second or 30 seconds??

I mean why the heck would a sensor need a whole 30 seconds to capture an image?? I really don't get it.

Again it had NOTHING to do with how fast light moves, it has EVERYTHING to do with how much light there is.

 

[Bebulamar]

SnapSnap you must be a genius! I have never heard anyone posing your question so you have my vote for being creative. But sorry I think your question is a challenge to us and not one of a wondering mind so there is no answer for you.