Hand of God

I've never fully understood in what manner these images are colorized...

I see from the link to "unusually colored image" that the hubble uses six different color filters...which doesn't really explain much to me as a lay person.

I understand that the light and shadow, and form are all directly taken from the hubble images, but I don't understand the filtering process which leaves me with two questions:

1. Is this more of a real photograph of that area, or more of an artist's conception of that area?

2. If the former, assuming I was floating around out and about in the nebula, is this what it would look like to my naked eyes?
 
Andonyx said:

1. Is this more of a real photograph of that area, or more of an artist's conception of that area?

2. If the former, assuming I was floating around out and about in the nebula, is this what it would look like to my naked eyes?
Click to expand...

My understanding (possibly not correct) is that this is sort of "false color" - ie, someone picks out the colors to be used for artistic reasons, but exactly where they get applied and how much is based on actual spectral information. So this is not what it would look like if you were there (among other things it would probably be a lot darker), but color differences are indicative of genuine differences, even if they wouldn't be obvious to the naked eye.
 
"False color" images are usually interpretations of images taken in infrared, radio, ultraviolet, or x-rays, none of which can be seen by our eyes. The color scheme usually mimics visible light with the shorter wavelengths at the blue end and the longer wavelengths at the red end. Or blue light indicates lower intensities or energies and red colors the higher intensities or energies. False color images usually include an explanation of the color scheme.

Color filters are used in visible light photos to enhance certain features by improving contrast or surpressing brighter features.

Many objects, such as emission nebulae, do have inherent color, such as the characteristic emissions from ionized gases. But filters and other techniques may be required to make the faint colors obvious...
 
This might help with the concept of false colour images. I used to work in the photo lab at a remote sensing facility. Landsat sattelite data had images based on four different spectral sensitivities. IR would be one of them for example. The data was imaged with a laser beam film recorder on B&W film. We would take these processed images and hand register them (line them up with each other). We would take three of the images into the dark room and expose a piece of Ektachrome (8*10 inch) with red, green and blue light. With each colour being exposed through one of the bands. When the film was processed the result was a false colour image. It might appear orange where forests were growing. We did a couple of different combinations of these depending on the end user. The whole point being to use the false colours to help seprate data in the image and enable easier interpretation of the information. This is all done with software now.

Interestingly this is quite similar to Technicolor where film footage is shot in B&W and three images are produced. Each shot through a colour filter of red, green and blue. When printed to colour print film in a process similar to what I described you get 'Gone with the Wind' in wonderful technicolor..
 
Thanks everybody.

I think I get it now. It's almost like a topographical map in which the colors change relative to some discernible property, such as elevation. Got it.
 
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