Sunday, February 28, 2010

Night Photography

In a much earlier posting from 2007, I talked about shooting Sunsets. I am currently teaching a Digital Photography course and the next project involved night photography. So, for their benefit and yours, here is some things to keep in mind when shooting at night:

-If you are including the moon, sunset, or sunrise, consider where it will be at the time of your shoot. OF course, the sun rises in the east and sets in the west (changes a little throughout the year, but not much). So, you will get a vastly different photo when shooting sunrises to the east or sunsets to the west.

-It is going to be very dark. Bring a flashlight. This will help you see your camera as well as see where you are going.

-You must use a tripod as exposure times will be long

-Use a remote release to trigger your camera. Or use the self timer if the timing of the shutter release isn't critical. You may want to invest in a cable release which has a timer function. This will allow you to use a shutter speed longer than what the camera otherwise offers. For example, the longest shutter speed my Nikon D300 offers is 30 seconds. If I need a shutter speed longer than that, I have to use the Bulb setting. In that mode, you have to hold the shutter release button down to keep the shutter open. This is not conducive to sharp photos. Higher end cable releases have timer functions built in that will allow you to set longer times and hold them with a single press of the cable release button.

-Use the mirror lock up or anti-shock feature of your camera. This will help insure that the photo won't be soft due to vibrations from the mirror (Only applies to those using DSLRs as compact digital cameras don't make use of a mirror).

-Turn on long exposure noise reduction if your camera has it. Most DSLRs and some compact cameras do. May have dig through the custom menus to activate it. The problem with this is your longer exposures will take a very long time to complete. Let’s say you take a 30 second exposure. First the camera takes the normal shot, and then it takes another 30 second shot in which the shutter doesn’t open. It takes the resulting noise pattern and subtracts it from the original exposure. It is very effective, but it really slows shooting down. Not a big deal when it is 80 degrees out, but it really stinks when it is 25 degrees out.

-Bring your camera’s instruction manual. You should always carry it with you anyways. If you are using a seldom used feature like long exposure noise reduction, then it is likely that you will have to look up how to activate it.

-Use your cameras lowest ISO. This assumes that you can use a very slow shutter speed as needed. For most of you this will require that you use the bulb mode in which the shutter will remain open as long as you keep the shutter release button pressed. Many of the remote releases have a provision to lock the button down until you release it. If your camera doesn’t have a slow enough shutter speed, then you may have to increase the ISO in order to obtain a correct exposure even when the aperture is lens all the way open.

-You may have to manually focus. All autofocus cameras require a certain light level to autofocus. If you are setting up in the dark, you will have precious little (if any light) so you may have to manually focus. If you have a DSLR, you can set the lens on infinity. You should note that the lens will likely allow you to focus past infinity. Past infinity?!? This is to take into account the expansion of the lens due to different weather, humidity, and pressure. So, you make have to take a few photos to insure that it is really set at infinity. Almost all compact digital cameras have a manual focus provision that entails selecting a distance from a distance scale. I simply set mine for infinity when using a compact camera. I was happy with the results. Another neat trick is to utilize an external flash. They often have a much more powerful autofocus assist light built in that will allow your camera to focus in pitch black night. So, you would use it focus, then turn the flash off.

-Consider all the ambient light sources unless. Even a very weak light adds up during a long exposure.

-Set your white balance to daylight. This will preserve the unique colors at that time of day. There is no point at getting up at 2am if you just want to take a photo that looks like it was taken at noon.

-Start taking photos before you even see the sun. There is usually a lot of color in the sky that you don't even notice until you take a long exposure photo and see it. Try it.

-Remember to expose for the highlights. Ensure that you are taking in enough light so that the histogram is very close to the right most wall without touching it. On a recent outing I noticed that some of my students were not doing that because it looked better on the LCD when it was underexposed. That is true. However, it will not look nearly as good as the image that was properly exposed once you begin editing on it the computer.

-Shoot RAW file format (assuming your camera supports it). If it is worth shooting, then it is worth shooting as a RAW file.

-Consider creating a HDR image from multiple, varying exposure (I will soon post more on HDR).

-Look for reflections in water (assuming there is water) that will give you twice the color.

-Bring a cell phone or a buddy; preferably both. If you are trouncing around in the dark it is a good idea to have a way of getting some help should you run into any trouble. Please take this seriously.


Steve Marsel said...

Ate you using Photomatix for the HDRs? Thanks in advance Steve Marsel

Seder said...

While I have used Photomantix for HDR, I generally use Photoshop CS4 as it is the program that my students are most likely to have or have access to. PS is really quite capable of stunning results. It gets a bad rap for its HDR capabilities, but I think that is because you have to be able to edit the tones using a Curve and many people can't pull it off. Photomantix is simpler to use. The HDR processing in CS5 is said to be improved. Thanks for your comment! Seder

alexcotton17 said...
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