Long Exposures

Comments

• Keebs

  June 2016

  Seconded!
• bruto

  June 2016 edited June 2016

  I think the Canon and Nikon are similar in that the way to get exposures up to a certain length is to use either shutter priority or manual exposure mode, and manually select a shutter time.
  
  At night, metering is essentially unworkable, and so is auto focus unless you can find a pinpoint of light, so you will probably have to set your AF to manual and try to focus manually. Use a tripod, and if focusing is difficult, switch to Live View ( back screen, whatever they call it in a Canon), and zoom that view in. On a Nikon this is done with the [+] button to the left of the screen. I'm sure there's a similar function in the Canon, but you may need to look it up. The screen view does not zoom the photograph, only the viewfinder.
  
  You'll have to guess the metering for long night shots, as most of the scene will be black. If you attempt to meter, the camera may overexpose and try to turn the image gray. If you have it on Auto ISO, it will crank the ISO way up into noisy territory. Try to keep ISO low for less noise.
  
  On the Nikon, the camera will only go up to 30 seconds. For longer exposures, you need the infrared remote timer. The "Bulb" function holds the shutter open as long as you want, but only when you are physically pushing the button, which leads to vibration. How your Canon works may vary, but there should be some way to get a true time exposure, in which one push of the shutter button opens it, and it stays open until you push it a second time. If you can accomplish that, you can make any length exposure limited only by battery life.
  
  There are various ways to try to figure the best exposure. You could start with manual, set the shutter at 30 seconds, the aperture wide open, and ISO 100. Take a picture. If it is too bright, either shorten the shutter time or close down the lens. If it is too dark, either increase the ISO or keep the shutter open for longer (if you can do this).
  
  It depends a lot on what you are shooting. If you are doing pinpoints of Christmas lights, you may want it quite dark to avoid blowing out the lights, but if a rainy night street scene, you may want it lighter than it really is, for an eerie moonlit look.
  
  For dark but not truly black night work, an alternative would be to use aperture priority. Again, use a tripod, and set the ISO manually low to avoid too much noise. Open up the aperture, and just hit the shutter. If the exposure meter calls for anything shorter than 30 seconds, it will work. If it's not very long, you can close down the aperture to get a bit more sharpness and less critical focus. If it's too long, you can raise the ISO, but be careful not to go up to high. Depending on subject and camera, you may do well up to 800 or more, but dark areas will look noisier than light ones, and a nighttime picture will suffer if it's too noisy.
  
  If the camera's exposure meter makes the scene brighter than you like, you can either use exposure compensation to darken it, or darken it in post processing. You can adjust exposure in a Raw file easily, and the advantage to this is that when you darken a picture that is a bit too bright, you reduce the noise some at the same time.