onsdag 8. april 2009

Ansel Adams, the first HDR pioneer

Photographers have always tried to take advantage of the huge dynamic range that we see around us. The process to bring out that dynamic range in a photograph have been going on since the camera was invented.
One of the pioneers in this high dynamic range field is Ansel Adams.

William Turnage describes Adams this way: "He manipulated the work tremendously in the darkroom. He always said that the negative is the equivalent of the composer's score and the print is the equivalent of the conductor's performance, and the same piece of Mozart is conducted differently, performed differently, by different orchestras, different conductors, and Ansel performed his own negatives differently."

How to get 9 shots in AEB on Canon 40D

Canon only implemented 3 shots in Auto Exposure Bracketing mode (AEB) on the 40D/50D. Even the 5D mkII has only 3 shots in AEB.
The rumors says that the 60D will have 9 shots in AEB, we'll see...

But 3 exposures is not enough if you shoot scenes with a lot of dynamic range and want to create HDR/Tone Mapped images. In normal situations it is enough with 6 exposures ranging from -3 ev to +2ev with a 1ev interval.
That can be achieved fairly easy using the exposure compensation dial. Here's how:
  1. Use a tripod!
  2. Use manual ISO, as low as possible.
  3. Use 1/2-stop increments on the exposure compensation dial, not 1/3.
  4. Set the AEB to -1 0 +1. You'll now see three markers in the display that shows the AEB value, to begin with it will show -1 0 +1.
  5. Set the drive to 2 second (self timer).
  6. Use aperture program (A). If your shooting landscape you'll properly want to use a small aperture like f/16 or f/22, maybe even smaller like f/32.
  7. Frame and focus the shot.
  8. Switch on manual focus so that the focus is the same in all 6 shots.
  9. Turn the exposure compensation all the way to the left to get three underexposed shots, -3 -2 -1. The display will now show one marker on -1 and one blinking marker on -2 telling you that the third marker is on -3 :)
  10. Press the shutter, wait those 2 seconds and let the camera shoot 3 exposures.
  11. Quickly turn the rear dial to control the exposure compensation up to 0 +1 +2. That will be 4 ticks if you use 1/2-stop increments on the exposure compensation dial.
  12. Press the shutter, wait those 2 seconds and let the camera shoot 3 exposures.
  13. You now have 6 exposures at -3ev -2ev -1ev 0ev +1ev +2ev.

OK that will be sufficient for most situations, but if you shoot directly into the sun, you'll want more underexposed images. If you add another little procedure to the one above, it is possible to shot 3 more exposures fairly quickly:
  1. Follow step 1-9.
  2. Press the shutter half way down to read aperture and shutter speed for the -3 settings. That could be f/22 and 1/180 sec.
  3. Switch to manual mode (M) and set the aperture to the same value that you used in aperture mode (f/22). Set the shutter speed -2 stops lower, that would be 1/750 sec. With a little practice this is done very quickly by turning the dial for the shutter speed four ticks (2 stops) to the left.
  4. Press the shutter, wait those 2 seconds and let the camera shoot 3 exposures.
  5. Switch back to aperture mode (A).
  6. Proceed with step 10-13.
This will give you 9 exposures ranging from -6ev - +2ev, enough exposures to shoot directly into the sun :)

What you do with those 9 exposures is a whole different story, but they make the perfect starting point for some nice into-the-sun-hdr-shots :))

Addicted to Sun

mandag 6. april 2009

iPhone Sunrise / Sunset applications

Landscape photographers love to shoot in the hour around sunset and sunrise. But how do you know when an where the sun will show up or disappear?

There is several iPhone applications that helps you to calculate the movement of the sun and the moon. I have tried several free applications, but these two applications is all I need to know when the sun & moon will be where :)

Sunrise (1$) is a simple utility to calculate sunrise, solar noon, and sunset times, as well as the phase of the moon.
By default, it shows the information for the current day at the current location, but Sunrise can calculate any day in the past or future for locations around the world.

Sunrise uses iPhone and iPod touch’s ability to locate itself to determine the latitude and longitude for its calculations, so you don’t have to pick a city or location — it’s automatic.

In addition to using the current location, Sunrise has a self-contained list of locations from around the world for displaying times for other locations, or for iPod touch users who cannot use location services.

When using locations from the database, Sunrise can operate without a WiFi, cellular or GPS signal.

The Focalware iPhone Application Helps Photographers and Filmmakers Know the Position of the Sun and Moon - Anywhere, Any Time
Focalware is a photography application that calculates the position of the sun and moon anywhere in the world and at any time by utilizing GPS location and date information.

Focalware helps photographers and filmmakers around the globe plan optimal shots with accuracy and maximize their shooting schedules. For example, if a photographer has an assignment for a shoot in New York City on March 15, 2009 and the building in the shot faces 195 degrees but the photographer prefers raking light at an angle of 130 degrees, Focalware instantly computes a time of 10:28 a.m. with a sun elevation of 35 degrees as the time for the desired conditions.