Clouds, why do they change color?

Marquise · Post by **Marquise** » Mon Mar 26, 2007 7:56 pm

My question is, Why do clouds chnage color with, or without, the flash on?
I was taking some pictures and i decided to do this fopr my project, but i dont know anything abut flashes and how they work.

jamescjb · Post by **jamescjb** » Mon Mar 26, 2007 11:21 pm

First of all, good observation. Well, now I think why don't you think about how the flash light works? When do you use flash light, at night or at some other situations? And are there any differences between different kinds of clouds? My suggestion is to take different pictures at different time. Try to take pictures with and without using flash lights, and then compare your pictures. I hope it will work out.

You could use internet to research for how flash light works.

Your observation is pretty interesting. Keep it up!

deleted-71588 · Post by **deleted-71588** » Wed Mar 28, 2007 5:12 am

Is this a photography question? If it is, then are you using film or digital? If you are using film, is it negative film and are you evaluating prints?

Marquise · Post by **Marquise** » Wed Mar 28, 2007 9:16 am

Craig_Bridge wrote:Is this a photography question? If it is, then are you using film or digital? If you are using film, is it negative film and are you evaluating prints?

Yes it is. All i have right now is a digital. And thank you for your help though

deleted-71588 · Post by **deleted-71588** » Wed Mar 28, 2007 9:29 am

You need to do some reading on "Exposure". The metering systems in most cameras are based on an 18% reflectance neutral color.

Try running an experiment. Capture an image of a white sheet of paper that fills the entire frame and another of a black sheet of paper that again fills the entire frame. Compare the results. I expect both to look grey. The camera meter system doesn't know white from black if everything in the frame is the same.

Here are a couple links that explain exposure and light:
http://www.photo.net/learn/making-photographs/exposure
http://www.photo.net/learn/making-photographs/light

JanelleSchlossberger · Mon Apr 02, 2007 5:08 pm

Dear Marquise,

You might also want to read about how your camera works from the user manual that it came with. (If you can't find it somtimes the web site from the company that made it has them available on line)

I believe that most digital camera flashes only provide enough light to illuminate an object that is relatively close to the camera (perhaps 20- 25 feet max).

When the flash is on, the camera is set to receive that reflected light from the object you're looking at and if that object is too far away (I assume the clouds are relatively high) then none of the light from the flash gets reflected back and the camera just takes a picture that is somewhat darker than normal.

When the flash is off, the camera adjusts automatically to the amount of light it receives from all the objects you're viewing and produces an image that appears to be as bright as the scene when you had observed it with your own eyes naturally.

Hope this helps to explain a bit more.

Regards,
Janelle

deleted-71576 · Post by **deleted-71576** » Mon Apr 02, 2007 5:54 pm

Craig is refererencing the phenomenon that is responsible here. Do a google, answers.com, or wikipedia search on "White Balance" and Digital photography.

An object that is illuminated by diferent light shows different colors with digital cameras (film too, but you're using a digital camera). While Janelle is certainly correct that your camera flash is not illuminating the clouds, your camera thinks it is, and is color correcting to compensate for the perceived color temperature of the flash). A way of standardizing this is using a target of a very specific color, known as an 18% reflectance neutral color target.

Most digital cameras get around this a slightly different way by having a setting where you can fill the entire frame with a white target. By having the camera adjust the "White Balance", it makes a calculation that changes how the colors are reproduced, essentially correcting for the color temperature of the light source. TV sets have similar ways of changing their color temperatures (crudely as tint, color, brightness, and contrast. You can try changing those values in your TV set (with an adult around) and see how the same image looks different depending on their values.)

Read the links that Craig has provided. I get the feeling that he's a pretty good photographer.