About After Midnight Landscapes
Well, all of the photos are not taken after midnight, but you get the idea. People have called this type of photography Landscape Astrophotography or more commonly "Nightscapes". I became interested after seeing photos on the web. I was immediately hooked, and the rest is history.
These photos require a very dark sky, and were taken in some of the darkest places in this country. There is a lot of subtle color in the night sky that the camera captures. The green is primarily “Airglow”, somewhat like the aurora. The sun’s extreme ultraviolet light excites oxygen and nitrogen atoms in the upper atmosphere during the day. The products then interact with other atmospheric components to later produce light emission by chemical luminescence at night. The camera can detect this but our eyes cannot. The yellow, orange, and red can be due to the setting sun or moon, and in large part due to light pollution. Light pollution can be seen for hundreds of miles. There is also a lot of subtle color in the core of the Milky Way that is simply beautiful. In many of these photos the nearby landscape is illuminated to some degree (light painting).
So why do this at all? Living in the Eastern USA I was not used to actually seeing the real beauty of the night sky. The light pollution in the East obscures many of the stars as well as the Milky Way. You have to actively seek the darkest skies in the country to see the sky as our ancestors did. It is exhilarating to be in these places at night and see the Milky Way arching overhead. There is a feeling that is almost primal to see the sky just as our ancestors did thousands of years ago, maybe one of the few experiences we can still share with them.
We have largely forgotten the beauty of the night, especially in the eastern US. When the sun sets we go indoors and turn on the lights, and spend little time outdoors. People have learned to fear the night. Seeking out the night sky has been an exciting experience. The sky is beautiful. The land is still and quiet. The crowds of the day are gone. Occasionally a rabbit, or fox, or mouse will appear and then scurry away. It is peaceful and quiet in a way that we have forgotten.
For those that have not tried this kind of photography, here is a little background. Those photos are taken in the darkest places possible, to allow you to see the Milky Way and stars. There are "Dark Sky" apps that can help show you the darkest places in the world. Moonlight is usually too bright and this means that you take those photos around the time of the new moon, or well after the moon has set. Most of these photography trips are planned around a new moon to minimize moonlight. All of the exposures are long exposures, usually 15-30 seconds. All are taken with a tripod. Since the stars are moving in the sky, you will get "star trails" if you use exposures longer than 15-30 seconds. This means the stars turn from dots into curved lines that look like small commas. Twilight (the time after sunset) lasts much longer than most people realize. There is some residual light from the sun for up to two hours or so after sunset, and most of the photography is obtained after that time. You also need a camera that is very sensitive and functions well in low light. As for the landscape you can provide lighting or leave it natural. There are times each may be best.
By profession I am a Radiologist. Photography and Radiology share many of the same principles as far as image capture and display, both in the eras of film and digital imaging. As photographs moved into digital imaging so did x-ray. I suspect an interest in photography while in college later helped to stimulate an interest in Radiology. My primary interests are outdoor and travel photography. I have had a longstanding interest in travel, and travel as much as my life will allow. Over the years my interest in landscape photography has opened up a world that I may have otherwise never experienced.
The photos were taken with a variety of cameras over the years, changing with the times. The 35mm and digital cameras were Canon with a few rare exceptions. Earlier Medium Format cameras were Bronica and Contax. Over the last few years the cameras have been Canon Digital SLR's, most recently the 6D, 5D Mark III, and 1Ds Mk III. Canon lens include the 16-35mm 2.8L II, 28mm f1.8, 100mm 2.8 Macro, 70-200mm f4 L IS, and the 100-400mm f4.5-5.6 IS L. Non Canon lens include the Sigma 15 mm f 2.8 fisheye, and the Nikon 12-24 mm f 2.8 zoom, and the Rokinon 24mm f 1.4. I use a Gitzo G 1128 MK2 tripod and an Acratech Ballhead and leveling base. I find that as time goes by I use less filters, with the exception of a polarizing filter. Image processing is done on a Mac Computer with Adobe LightRoom 5.0 and Photoshop CC. I am currently printing either on an Epson Stylus Photo R1900 Printer or use Bay Photo as a commercial lab. Virtually all of the daytime images were taken with available light. "Light painting" is used in many of the night photos. If there are any questions please contact me by email.
I'll try to pass along some workflow ideas, as these change and evolve. It changes as I learn.
There is a choice you have to make at some point in the processing. It can be made initially or later. If you want the sky to be blue with a cooler look overall, you will want to process the sky with a cooler white balance. This usually turns the highlights in the Milky Way a magenta color, and is very pretty. This seems to be the most common choice photographers make. The sky experts say that the real color of the Milky Way is more yellow, and they assume the sky is black (and I suppose it is out in space!). If you use the Temp and Tone curves to make the darkest part of the sky a dark grey, several things happen. The Milky way develops a yellow hue rather than magenta. The stars develop individual colors. If you look closely you will see blue, yellow, red, white, and occasionally orange stars, with the largest number being blue. This reflects the temperature at which the stars burn, the bluer stars burning hotter. This is a better reflection of real life. If you process the sky as a "cool" blue color it will in part cover up airglow (green) and light pollution (yellow, orange, red). If you process the sky more neutral or more "warm" you will find a lot of subtle color coming out. The airglow and light pollution shows up much more vividly. It can be attractive or a nuisance. You can then try to make the light pollution and airglow go away, or you can embrace it and work with it. This can make the sky look very surrealistic, with lots of green, yellow, orange and red. IT can look beautiful but very otherworldly. Lots of photographers try to get rid of this color to make the sky look more natural or more like we expect. Lately I have stopped trying to get rid of these colors and have embraced them (at least for now). A good choice might be to process the sky more neutral to start with and then adjust the color later as desired. You could select the sky in photoshop and then use the color tools.
The initial part of processing can be done in Adobe RAW or Lightroom (I use Lightroom). For processing I usually make the darkest part of the sky as neutral as possible in Lightroom (using the Temp and Tint sliders). It is hard to get it perfect, at least for me. When I say I make the sky as neutral as possible, I do this: I pick the darkest area and try to make it grey or only slightly tinted. The easiest way to do this is to look at the separate histograms for red, green and blue in the histogram graph and use the Temp and Tint sliders to get the separate color curves to overlap or match up as best you can. Overlap or superimpose the blue and yellow peaks (in the part on the histogram that represents the sky - the large rightmost peak), then superimpose the green and magenta peaks as best you can, then go back and superimpose the blue and yellow peaks again, keeping an eye on the darkest sky. This means that you no longer have a cool or warm tone bias. The more neutral you make the dark sky, the more subtle color you can bring out elsewhere. If I want to end up with a blue sky I will then move the Temp slider very minimally to the left (one click). This is virtually un-noticeable at this stage. To get a preview of what the sky will eventually look like go to the "Tone Curve" function in Lightroom. Click on the little square in the bottom right hand corner, so you can manipulate the curve freely. The place a very steep "S" shape on the curve, up at the top and down on the bottom. This will increase the contrast tremendously, and you can see which way the color is trending. I like to leave it with a minimally blue bias in the darkest sky. Then right click on the curve and click "flatten curve", and the sky will return to a grey flat color (contrast will be applied later in Photoshop). Usually the upper sky is so much darker than the lower sky that I may lighten the upper sky with a gradient in Lightroom to make the sky more uniform in density. This helps a lot in processing the sky later. I also do noise reduction, sharpening, and lens correction in Lightroom and export to Photoshop. You can do all of this in Adobe RAW with the exception of the gradient function. In Lightroom or Adobe Raw here are some good initial settings for sharpening and noise reduction for an ISO of 6400 in a Canon 6D:
For sharpening, Amount 25 (you can sharpen later in Photoshop if necessary), Radius 0.7, Detail 15-20, Masking 75. For noise reduction, Luminance about 40-50, Detail 50, Contrast 50, Color about 17-20, Detail 50, smoothness 100. The amount of noise reduction you need will vary with your camera and ISO. I use the Lens Profile correction function. I then export or open in Photoshop. To do this right click the image and choose "Edit in Photoshop". In Photoshop I carefully select the sky and foreground and save the selections separately. I chose the sky and may increase the vibrance by 10-25. This darkens the color in the sky slightly. You can darken the sky primarily in Curves by adding contrast, but if this is your primary way to darken the sky, then you may be adding a lot of noise and graininess. I mildly increase the vibrance first, then mildly increase the contrast in curves use a "S" shaped curve. Increasing the vibrance first means that you can use a smaller contrast adjustment in curves to darken the sky, and end up with a less noisy and less contrasty sky. Many times the sky can end up looking overly sharp, and this helps to lessen that effect. I then go to levels and move the left most slider slightly to the right. This darkens the sky without significantly changing the lighter tones.
I find that this will really bring out the subtle sky colors if you start with a neutral sky. If you make the sky very blue in Lightroom from the very beginning, them you cover up a lot of the subtle colors in the sky, and also you can give the airglow and light pollution unpleasant color casts. Airglow and light pollution can be attractive! I may make small changes in the color of the sky primarily with the Color Balance function. I frequently choose the Milky Way with the lasso tool and feather it about 200 pixels, and then use then adjust the brightness and contrast and vibrance. I frequently chose the lower sky separately and darken it, as it is usually much brighter than the rest of the sky.This often improves the color tones in the MW, but not always. I then chose the foreground and adjust the contrast separately in curves. I do a little dodging and burning for hot areas or areas that are too dark, and that's about it. I commonly increase the local contrast using the Unsharp Mask function, using an Amount of 10-20, a radius of 40-50, and a threshold of 0. This increases local contrast and gives the impression of sharpness, without increasing the perceived noise too much. Using the sharpening tools in the usual way of a high amount and a low radius creates too much noise in high ISO images.If there is too much noise I use the Topaz noise reduction plug-in. It is remarkable good at reducing noise without making the image too soft.