Hardware
Camera: Canon EOS 6D
Lens: Canon EF 17-40mm f/4L USM
Tripod: Oben
Shutter release; wired timer Vello ShutterBoss Remote
Head lamp
Software
Adobe Photoshop Lightroom 5.3
Adobe Photoshop CC
Other
Wacom Intuos Pen and Touch pen tablet
There are not very many places near Thunder Bay with ideal conditions for night photography but clear cloudless skies help. This night was probably as good as it gets considering the location. Moon is also a major light source in the night sky so observing moon phases when preparing for night shoots is equally important; of course new moon is best. This was photo was taken on the 22nd of September 2014 so the moon was old but wasn't to rise until 2:30 AM so I had a moonless sky to work with. Photographing the milky way in our area is probably best done in early to mid summer. In September, the brightest part or the Milky Way is visible immediately after sunset just above the horizon which isn't dark enough for getting good shot. July would have been better. I was also already out for a few hours before I arrived at this location but some of brighter part of the Milky Way was still visible.
When it comes to composing and focusing in the dark there is a lot of trial and error involved because there is nothing, or very little, to see in the viewfinder or in live view. What I do is set the lens to it's infinity mark, and crank up the ISO to max, set the camera to level and start taking quick test shots. With ISO cranked up real high I don't need to expose for too long. I look at the results in preview and recompose if necessary and repeat until I like the composition. When satisfied with composition I magnify the test shot in preview to verify that focus is satisfactory. Since the lens aperture has to be wide open for this type of photography, the photo will not be very sharp but that is to be expected. If focus is not satisfactory then I make very small adjustments using the focus ring until I find the "sweet" infinity focus spot. The marks on the lens are not always in perfect. Some photogs recommend finding and marking your own spot on the lens but it is best done in daylights. When I am happy with composition and focus, I adjust ISO to a reasonable setting and program my exposure time.
I already know the approximate correct exposure time for my lenses in various situations. To figure this out a formula is used but tables with common exposure times are also available on the web. This formula is sometimes called the "600" rule. It is important to factor in the focal length and sensor size (full frame, APS-C "cropped", etc), In short, because stars move very quickly across the night sky, too much time and the starts in the photo will start to trail (instead of dots they will become short lines), but too little time and the stars wont be bright enough. For the lens I used, and at 17mm, I used 34 second exposure time and ISO 6400. ISO 6400 may sound like too much but Canon 6D controls noise quite well and I personally rather have a little noise and brighter stars in my photo. My lens is also not "ideal" for this type of photography, an f2.8 or faster would have been better which would allow me to drop the ISO but I have to work with what I have.
With the camera firmly mounted on a tripod, I programmed my shutter release timer to 34 seconds, set white balance to 4000K and went to work; test shots, check the results, recompose, refocus, check again, ISO to ....
Once I imported my RAW shot into Lightroom 5, I made a virtual copy of the same image and processed one for ideal foreground and the other for ideal night sky look. I won't go into much detail here; post processing can be time consuming and requires a solid understating of all the available tools in Lightroom. The important part here is that although I used a single original shot, I processed the 2 copies of the same shot differently; in one I focused only on the sky the other copy I focused on everything else but the sky. I micro tweaked and re-tweaked most settings until I was happy with each copy. When preparing an image for subsequent layer masking work in Photoshop it is important to keep in mind that the colour tone and warmth of both copies match in order to produce a natural-looking final image. When done with processing both copies in LR5 which took me about an hour I loaded both copies into Photoshop CC. I created a layer mask and manually masked the night sky. In the past I used a mouse but I recently acquired a Wacom pen and touch tablet which allows me to use an actual pen on the tabled surface. (very natural and no wrist pain) To mask properly is time consuming and there is no quick way to do it; I brushed the mask along the edges of the foreground and the sky at various levels of intensity to make a natural seam between the 2 copies. It took me about an hour in Photoshop to do this but I am still getting used to my Wacom tablet.
Planning is important and this composition was planned; I knew I will get the light ppollution illumination on the cliffs because I've taken numerous nights shots in this area in the past. I also knew where the Milky way will be and that I will get some starts in the shot and because I am familiar with the area and that I wanted to take this shot from that particular spot on the road. However, I was also planning another shot earlier the same night and it was a bust. Sometimes things come together as planned, most often they do not.
Additional tips:
ALWAYS shoot RAW!
Camera Long Exposure Noise Reduction: Many photogs and long exposure related articles recommend that in-Camera Long Exposure Noise Reduction be turned ON. The camera will automatically take another shot with the same exposure time and it will then used this "dark frame" to attempt to remove noise from dark areas of the photo. Until recently I have been leaving this setting on but I no longer do so mainly because it takes TOO much time for the camera to take the second shot and do the processing. The darker the photo, the longer the process takes. Instead of being able to take a shot every 34 seconds, it takes at least triple the time. Since conditions change quickly in the field (star movement, sunrise & sunset, bands of dancing aurora) I found I was missing too many shots while waiting for camera to remove noise from my previous frame. I turned the feature off and night photography instantly become a lot more fun. The difference between photos taken with and without noise reduction is barely noticeable and I rather correct for noise in post than miss a shot in the field.
