Tuesday, December 24, 2013

Manual HDR Photography

To be clear from the beginning, this is about manual, i.e. as not automated, HDR photography, not handheld. Although it could potentially be done handheld, for starters I recommend a tripod.

Outside it is raining cats and dogs with a lovely storm going on, hence, I decided to stay inside this Christmas eve. Consequently, there are no landscape or architecture photos accompanying this particular post.

Some years ago, I picked up a P&S camera for various low demand purposes.
Selection criteria: it needed to
  • be inexpensive
  • run on AA or AAA batteries
  • use SD-cards
  • have a tripod mount.
That was essentially it. The choice fell on a Samsung S760, which serves me well. Most of the photos shown on my other blog (draaggolf.blogspot.com) are actually shot with this particular camera.

You may have guessed from my blog, that I experimented with HDR for a few weeks. Fun stuff. However, the variety of AE-bracketing cameras is rather limited and placed at the higher price segment, cf. http://www.hdr-photography.com/aeb.html.
However, we know that all that is required are 3, maybe even only 2, images of the same scene, with the same aperture but different shutter speeds.
Of course it is very convenient if AEB is already built into the camera in an automated way, in particular if it is as speedy as the 11fps of the LX7. But, it can be done with almost every digital camera on the market, provided that the camera has got a possibility to adjust exposure compensation, in one or the other way, and preferably has got a tripod mount.

Here is where in S760 came in. The camera employ a manual mode, with a +/-2 exposure meter... very handy! And, in addition to that, this particular model is equipped with a 2s or 10s self-timer.

Here's my workflow for bracketed exposures using the Samsung S760:
  1. Mount the camera on a tripod and set your scene.
  2. Switch mode dial to "P".
  3. Power up.
  4. Half-press the shutter release, the aperture and the shutter speed for a "normal" exposure will be displayed; try to memorize the numbers.
  5. Change mode dial to "M".
  6. Hit the "Fn" button, aperture and shutter-speed will be displayed in red.
  7. Introduce those values with the "5 function button". This will be you middle frame.
  8. Hit "OK" to confirm the settings; aperture and shutter speed will be displayed in white.
  9. Engage the 2s timer by pressing the right part of the "5 function button" twice.
  10. Press the shutter release to start timer and step back!
  11. From here on, steps 6 to 10 will be repeated with difference that in step 7, only the shutter speeds should be changed. Multiply the shutter time by 4 to obtain a +2EV frame, divide the shutter time by 4 for a -2 EV frame.
Quick and dirty through the window demonstration:





HDR by exposure fusion

I am not sure what blogger does, it seems that blogger tries to "improve" the images... the original of the over-exposed frame is much brighter and the under-exposed is much much darker. Anyway, you get the idea...

The only downside to the whole story is that this camera, like all in-expensive P&S cameras, does not write RAW files. Compression artifacts may cause problems under certain circumstances.

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