Blue Hour and HDR Tutorial by John Strung the Blue Hour is a wonderful time of night when photography can yield images of intense blue colours. Blue Hour is a bit of a misnomer for two reasons. There are actually two blue hours each day, and they usually last only about a half an hour each.
The morning blue hour typically starts an hour before sunrise and ends an half an hour before sunrise. The evening blue hour typically starts a half an hour after sunset and ends a half hour after sunset. However, the blue hour is a continuum with the most intense colours coming somewhere in the middle. A Blue Hour App is available for iphones which will calculate when the blue hour starts and ends for your particular location and date. Some Tips for Blue Hour Photography
Artificial light contrast very nicely with the sky at blue hour
Shoot Raw Set the white blanced to Tungsten Bulk adjust the white balance before exporting to your HDR software Use a large f-stop to get the star effect for lights Consider using a wide-angle lens Use HDR A wide-angle lens: 1. Adds depth and perspective. 2. Increases depth of field 3. Allows you to make use of foreground and converging lines. The image at right was shot at 16mm on a full frame camera, the equivalent of 10mm on a crop frame. Note that it is sharp all the way from the edge of the pier at the lower right to the lights in the far distance. The converging lines of the edges of the pier add to the sense of perspective.
Focusing You may have to use manual focus at night if there is not enough light for your camera to autofocus It is important know your depth of field. Depth of Field Focusing at the hyperfocal distance yields the greatest depth of field for your camera, lens and f-stop combination. (The "hyperfocal distance" is the closest distance that you can focus your camera and still have it sharp at infinity). For instance, using a Canon 6D, the hyperfocal distance for a 100 mm lens at f8 is roughly 137 feet. Focusing at 137 feet will yield an image with everything in focus from roughly 70 feet to infinity. By contrast, using a 16mm lens at f8 yields a hyperfocal distance of slightly less than 4 feet, and focusing at 4 feet will yield an image with everything from 2 feet to infinity in focus. What this means is, if you are using a 16mm lens, you can simply set it to manual focus at the beginning of the shoot, focus at 4 feet and never have to refocus all evening. Everything from 2 feet to infinity will be in focus. Depth of Field preview on your camera will not work at night. I highly recommend the inexpensive iphone App Simple Depth of Field which will quickly and easily calculate the hyperfocal distance and depth of field for your camera, f-stop setting and lens. I find it absolutely invaluable in ensuring sharp pictures and an appropriate depth of field
The Simple Depth of Field App, above, showing the hyperfocal distance for a 100mm lens at f8 to be 137 0.36. When focusing at 138, everything from 68 9.07 to infinity is in focus. The Simple Depth of Field App, above, showing the hyperfocal distance for a 16mm lens at f8 to be 3 6.62. When focusing at 4, everything from 1 10.56 to infinity is in focus. HDR The last piece of the puzzle is to use HDR for your blue hour photography. HDR photography gets a bit of a bad rap from people who think its sole purpose is for special effects photography. That is not the case all. HDR stands for High Dynamic Range photography. It actually originated as an attempt to make photographs look more realistic. Cameras do not have as large a dynamic range as the human eye. If you look at a landscape on a sunny day, your eye can see the clouds in the sky at the same time as it can see the details in the shadows. Cameras can't yet do that. If you expose for the clouds in the sky, you lose the details in the shadows. If you expose for the shadows, the sky is blown out. That is why so often shots we take of landscapes do not seem as vivid as we recall the scene being. HDR photography attempts to remedy this by combining multiple exposures. In the simple example above, you would take three separate shots, one exposing the sky correctly, one exposing the shadows correctly, and one exposing the midrange correctly, and then combine the three to approximate what the eye actually sees.
This sounds complicated, but modern cameras and software make it easy. In fact, modern cameras make it easy to take HDR photos with 3, 5 or 7 images. The image below is an HDR composite of 5 different exposures. The image on the right is the middle of the 5 exposures Compared to the HDR image on the left, the single exposure image above has blown out highlights in the streetlight and at the base of the lighthouse, and has no colour or detail in the lake or sky or below the pier. HDR is useful whenever your subject has a larger dynamic range than your camera can handle. It can be particularly useful for shooting into the sun or for getting texture in snow.
HDR is also useful for indoor architectural photography. If HDR had not been used for the image below of the Notre-Dame Basilica in Montreal, the bright chancel would have been blown out and there would have been little or no detail in the dark areas under the balconies.
Making and HDR Image 1. Camera Settings - taking the photo Use a tripod. Set your camera to Aperture Prioritymode (Av on Canons, A on Nikons), with a fixed (not Auto) ISO setting, so that only the shutter speed changes between exposures. Most cameras have an "Auto Exposure Bracketing" setting which will allow you to set the camera to take 3, 5 or 7 shots at different exposures automatically. You may have to consult your camera manual. The photo below shows a Canon 6D set to take 5 shots, the first 2 stops underexposed, then 1 stop underexposed, then correctly exposed, then 1 stop overexposed, then 2 stops overexposed. If the camera is set to the timer mode, you only have to press the shutter once and it will automatically take all 5 shots one after the other. Exposure Tip: Most cameras will not let you take an exposure longer than 30 seconds unless you use the manual "bulb" setting. When shooting HDR, to ensure that your longest exposure is 30 seconds, set up your camera as above and press the shutter half way down to see what shutter speed the camera will automatically expose for. Then, assuming you are going take HDR shots over a range of -2 to +2 EV (as above) change your ISO so that the shutter speed is shown as 8 seconds. This will result in exposures of 30, 16, 8, 4 and 2 seconds. (If you are going to shoot a range of -3 to +3, set your ISO so that the metered shutter speed is 4 seconds). Combining and Processing the Images
Combining and processing the images is done most easily using a plug-in. The two most popular ones are Photomatix https://www.hdrsoft.com/index.html and Nik HDR Efex Pro https://www.google.com/nikcollection/products/hdr-efex-pro. Both will work as plug-ins for Lightroom and Aperture. HDR Efex Pro will also work as a plug-in for Photoshop and Photoshop Elements. Although HDR Efex Pro is a little more expensive than Photomatix, it comes as part of a suite of 7 plug-ins, so you get an additional 6 plug-ins for the price. There are good video tutorials for using both of these tools on the web sites linked above. Basically, it is just a matter of selecting the 3, 5 or 7 images you took in the Aperture or Lightroom browser, then pulling down a menu to invoke the plug-in. The software will then combine the images and give you a choice of various effects you can apply. If you used a tripod for your shots, you should turn off "auto-align" in your HDR software to get a better result. With a little practice and experimenting, you will find that you can process HDR images quickly and effectively. Useful Links 1. Blue Hour Trillium Club s Night Photography Interest Group see Night & Long Exposure PDF HDR Night Photography Tips: The Magical Blue Hour - http://www.joshuaguntherphotography.com/tutorials/hdr-night-photography-tips-themagical-blue-hour/ 5 Ways to Improve Your Blue Hour Photography http://www.hdrone.com/2013/03/5-ways-to-improve-your-blue-hour-photography/ How to Photography the Blue Hours With Amazing Results - https://www.lightstalking.com/blue-hours/ Blue Hour Calculator http://jekophoto.eu/tools/twilight-calculator-blue-hour-golden-hour/ Blue Hour App - https://itunes.apple.com/ca/app/bluehourapp/id425965523?mt=8 https://itunes.apple.com/ca/app/simple-dof-calculator/id301222730?mt=8 2. Wide Angle Lens Simple Depth of Field App - Why Your Next Lens Should be a Wide Angle - refer to the PDF on the Trillium Website http://wh425991.ispot.cc/wp-content/uploads/2017/11/6-wide-angle-lens.pdf
3. HDR Photomatix HDR Plug-in - https://www.hdrsoft.com/index.html Nik HDR Efex Pro HDR Plug-in https://www.google.com/nikcollection/products/hdr-efex-pro/ HDR Tutorial How to Make Beautiful HDR Photos With Ease - https://www.stuckincustoms.com/hdr-tutorial/ The HDR Image - http://thehdrimage.com Cambridge in Colour HDR Photography - http://www.cambridgeincolour.com/tutorials/high-dynamic-range.htm