[HDR-photo] HDR Capture during changing light

[Ferrell McCollough]

To all:



I'm shooting a high contrast scene and during the bracket set, the sun comes out and lights up the scene. Should I start over? 

 

I'm shooting a dimly lit interior and a door opens and light spills in, should I start over?



These changes are easily 1 stop or more in lighting and if they happen during the exposure set will it impact the final image? Here's an extreme: I take the 0EV image, then a white puffy cloud drifts in front of the sun, I'm oblivious and I dial in +1EV and take the picture. What I've done is taken another shot at 0EV. Then, still oblivious, I dial in +2EV, but now the cloud is really blocking the sun, I end up capturing another shot at 0EV. I actually have three pictures all at 0EV but I think I have bracketed the scene 0EV, +1EV and +2EV!

 

OK it's not common, but it is possible, especially with interior work where shutter speeds are longer and exposure sets can take a few minutes. Low to medium contrast outdoor scenes can go pretty quickly in AEB continuous mode shooting 2 frames @ 2EV. I'm not talking about that, I'm talking about high contrast scenes that take more exposures and longer shutter speeds. An image set can easily take 2 minutes, especially with noise reduction mode turned on.



There seems to be two scenarios possible. One is shooting in manual mode. It will result in EXIF data that says +1EV but may not necessarily mean it. The light could actually read 0EV or 2EV as an example. The other scenario is when shooting in AEB the camera constantly responds to changes in light so when the shutter is released it is for sure +1 over the existing light. Its EXIF shutter speed may say +2EV from the 0EV exposure. 

 

A few of my thoughts:

  1.. AEB mode is better than manual mode when lighting conditions are changing.
  2.. If you are using merging software that allows you to over-ride the EXIF be really careful about doing this. You may recall shooting AEB at 1EV spacing but the shutter speed may not reflect it.
  3.. Recognize changing light during an exposure set and if it doesn't cost you anything, shoot the set again.
Regards to all,
Ferrell McCollough
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