M17, more light

Same shots as previously seen, but with another 30 minutes added. In this case, I am using the additional exposure to draw out more detail, rather than expand the amount of cloudy nebulosity. Since stacking large numbers of short exposures allows the signal to noise ratio to be improved, adding exposures lets me enhance the contrast without the grainy noise increasing.

This sort of nebula is a challenge for DSLR users; nearly all the activity is in the infrared, like any red/lavender emission nebula. There are several dark and dusty dark nebulae in the mix, but it takes a great amount of exposure time in visible wavelengths to get the bright stuff behind evident enough to outline the dark clouds.

M17 is often seen in photos to be much brighter and redder. Just another example of how many popular astrophotos have "cheated" the image slightly by using crimson red to represent hydrogen alpha wavelengths, even though those are not really visible with our eye. Of course, that is all good; there is no rule that photos cannot help us see what we otherwise would miss, and even the "natural color" pictures I try and produce are a "cheat". Our eyes would never see anything this faint, at least not in color.