Anything other then east and west (sunrise vs sunset)

[timmyquest]

Is there any differences in the colors? Logic tells me that in the summer a sunset would be more colorful because of all the added polution and heat of the day. But this is an untested theory mainly because it's easier to take pictures at 8:30 pm rather then 5:30 am

[CoolToolGuy]

There is a difference, and it has to do with the wavelengths of the light you see as the sun is rising or setting. I can't remember all of the details, but it seems to me that sunrises are more blue and sunsets are more red - but you might want to check about the actual colors. This was something I learned a long time ago. Someone else here may be able to be more precise.

Hope this helps
Have Fun
Rick 8)

[iwatkins]

I would agree, cooler in the morning and warmer in the evening (the light, not temperature).

But overall colour temperature would be the same for both sunset and sunrise assuming there was pure clean air.

On a still night, the wind usually dies down and pollutants, dust etc. tends to settle out. This leads to the light at sunrise being cooler than sunset. Sunset has had a whole day of atmospheric mixing, so dust pollution etc. is mixed up in the lower atmosphere which leads to a shift to the red end.

Of course, this doesn't always happen. Nice very windy day, with air off the sea etc. you won't see any difference really.

Cheers

Ian

[sdommin]

Is there any differences in the colors? Logic tells me that in the summer a sunset would be more colorful because of all the added polution and heat of the day.

You are correct. However, "more colorful" is a misleading term. SunRISES can be much more colorful than sunSETS - it depends on the atmosphere, and what your definition of "colorful" is. I think you mean to say that sunSETS are usually redder.

[Tom W]

the only thing I can remember is "red skies at night, sailor's delight; red skies in morning, sailors take warning". I'm not sure how it applies to photography though. :)

[iwatkins]

Tom,

Don't think it is relevent really. :P

But I have a new version:

"Red skies at night, photographers delight,
Red skies in the morning, photographers delight"

:wink:

Cheers

Ian

[Volatile]

any significant doppler effect? As the earth rotates away from the sun (sunset), the light would shift to the red. I just don't know if the speed of rotation is sufficient to cause a noticable effect...

[timmyquest]

any significant doppler effect? As the earth rotates away from the sun (sunset), the light would shift to the red. I just don't know if the speed of rotation is sufficient to cause a noticable effect...

The doppler effect wouldnt be at work here. The sun isnt actually coming towards or going away from us rather were just not looking at it anymore.

A good way to look at it is with the old speaker trick, swing a small speaker around on a string and you get the nce doppler effect.

Ok now imagine that instead of spinning the string around, you put the speaker in one spot and simply tippie toe in circles...can you see that there would be no doppler effect?

[iwatkins]

any significant doppler effect? As the earth rotates away from the sun (sunset), the light would shift to the red. I just don't know if the speed of rotation is sufficient to cause a noticable effect...

There probably is an effect, but probably far too small to measure. Rotational speed of a fixed point on the equator of the Earth is around 1000 miles an hour but speed of light is much faster. As I say, very small effect but difficult to measure and certainly wouldn't show up visually.

Cheers

Ian

[timmyquest]

any significant doppler effect? As the earth rotates away from the sun (sunset), the light would shift to the red. I just don't know if the speed of rotation is sufficient to cause a noticable effect...

There probably is an effect, but probably far too small to measure. Rotational speed of a fixed point on the equator of the Earth is around 1000 miles an hour but speed of light is much faster. As I say, very small effect but difficult to measure and certainly wouldn't show up visually.

Cheers

Ian

I'm not seeing how there is an effect here guys...the lack of light at night is due to the sun moving "below" the horizon, not away from it.

[iwatkins]

I'm not seeing how there is an effect here guys...the lack of light at night is due to the sun moving "below" the horizon, not away from it.

There isn't going to be a noticable effect anyway....

However, there will be a shift as the observer (say for this example) on the equator. The sun moves from overhead at midday to the horizon at sunset. The sun doesn't move but the observer does. The observer moves around 90 degrees in six hours due to the rotation of the Earth. That works out as a rotational speed of 1000 miles an hour.

In that period, the observer will have moved appox. 4000 miles further away from the sun (earth has a diameter of ~8000 miles). Therefore he will have moved 4000 miles further away during that six hour period. There will be a doppler shift of the sunlight because of it, but as I say, not noticable.

Cheers

Ian

[Volatile]

The effect is there for sure, but I did the math and it's too small to be noticed. On the order of a ten-thousandth of a nm shift in wavelength, at a middle latitude.

From what I can find, scientifically there is no difference between sunrise and sunset, aside from local amounts of airborne particles and clouds that affect sky color. Maybe it's just our imagination?

[PhotosGuy]

doppler shift...
Geeeez!!!