March 9, 2008

Last light. First lights.

Last light:

DSC_0010

First lights:

DSC_0005

Why is the blue in the first picture so much greener? I didn't do that. The sun did.

11 comments:

rhhardin said...

You see shorter wavelengths as the scattering angle to reach your eye gets steeper. ROYGBIV red orange yellow blue indigo violet.

Short wavelengths scatter steeper.

So the less scattered B still has some G.

rhhardin said...

...yellow green blue... it should read

Anthony said...

Technically, sunrise light (yellow) is coming out of evening light (blue) and sunset light (blue)is coming out of daylight (yellow), so the casts are slightly different, depending on the time.
You'd be lucky to catch them at the exact crossover time so that they'd have the same color balance.

Either way, it's nice.

MadisonMan said...

As you remove the light from the Sun -- which is primarily white with blue scattered out of it -- the sky will get bluer and bluer because only scattered light is reaching your camera.

Nitrogen and Oxygen atoms scatter very short wavelengths quite well -- that's blue/indigo/violet, as rhhardin notes. Your eye is much more adept at detecting blue light than indigo and violet (and the sun is emitting more blue light than indigo/violet).

Griff said...

I'm no scientist, but why does the setting sun appear in the same relative position to Manhattan's buildings as the rising sun?

Ann Althouse said...

These are both sunset pictures, taken a few minutes apart. "First lights" -- note the plural -- refers to the artificial lights that came on.

Ann Althouse said...

Anthony referred to "sunrise light." Not quite sure what he meant.

cardeblu said...

I got the "first lights" being the ones in the buildings, etc, but did you notice possibly Venus peaking through just "into" the blue? First, as well.

Michael said...

Ann: Why is the blue in the first picture so much greener? I didn't do that. The sun did.

I just checked the EXIF data of these two photos on Flickr. You used auto white balance for both of them. As the light changed, the camera automatically adjusted the individual gains for the red, green, and blue channels, using an algorithm known only to Nikon's engineers, thus giving you such drastically different results. That auto white balance is attempting to remove a color cast from your photographs.

As always, if you want the job done right, you're going to have to do it yourself. Check your D50's owners manual. "White Balance" should be in the index. I usually use the "Direct Sunlight" white balance to get the most pleasing colors for a sunset, prints of which you saw at the last Madison Althouse meetup.

Also, you overexposed the second shot. You probably maxed out the blue channel, thus allowing the red and green channels to catch up. While you have the manual out, check the index for "Histogram" and "Highlights."

Ann Althouse said...

Thanks, Michael, I've been trying to compensate by adjusting things in iPhoto after I've taken the picture, and I find I'm always turning down the exposure. I've spent some time trying to understand the manual and a website that puts the instructions more clearly, but I find it hopelessly obscure. I think the controls on the D50 are completely confusing when you leave the automatic setting. I'm not interested in the technical side of cameras, which seem built to fit the mindset of people who don't see a reason to use Apple computers. I'm interested in finding things to photograph and framing shots, not fiddling with a settings that are hard to see and troublesome to adjust and readjust.

Michael said...

Ann: Thanks, Michael, I've been trying to compensate by adjusting things in iPhoto after I've taken the picture, and I find I'm always turning down the exposure. I've spent some time trying to understand the manual and a website that puts the instructions more clearly, but I find it hopelessly obscure. I think the controls on the D50 are completely confusing when you leave the automatic setting. I'm not interested in the technical side of cameras, which seem built to fit the mindset of people who don't see a reason to use Apple computers. I'm interested in finding things to photograph and framing shots, not fiddling with a settings that are hard to see and troublesome to adjust and readjust.

The next time you're in Milwaukee with your D50 give me a buzz.