Saturday, March 22, 2014

Tone Mapping and HDR Photography


Anyone interested in tonemapping? It is very easy to do if you have the right software...I use Photoshop CS5 for RAW conversions and then Photomatix Pro for the HDR(1) generating and tonemapping.

You can generate HDR from one exposed photo but I find it best to secure camera on tripod and take at least three shots using AEB(2) if your camera has it, what you are looking for is underexposed shot to get details in the lighter areas, 'perfect' exposure for midtones and overexposure for details in the darker areas. If you don't own a tripod don't worry as you can fake it with RAW conversion...i.e change the exposure value before you open the RAW file, do this three times and save them to your desktop, open Photomatix and click on HDR tab on tool bar, then click where it says generate and it will then ask you to load images, browse to desktop and select your saved images, then click ok.

Photomatix will then come up with another box to align images, again click ok, wait for the script to do its magic and you will be presented with the worst looking image ever!!!! Fear not brave cameraists this is HDR in all its raw glory, you also will see a HDR viewer so as you scroll around the disaster scene you will see lots of detail in the viewer but not the bigger picture (seems ironic to me lol).

OK now we would normally bin this image as unusable so now comes the magic part...tonemapping! Hit HDR on the toolbox and in the dropdown menu seek out tonemap or hit ctrl+t, then more computing magic and you are presented with a much better looking image...play around with the strength and luminosity etc have fun!!! If anyone found this remotely interesting then I am quite prepared to carry on...let me know;o) HDR(1) - High Dynamic Range. It's a feature in Photoshop CS2 or Photomatix or FDRTools. A way to 'digitally develop' your photos using tonal information contained in multiple exposures of the same shot.

AEB(2)- Auto Exposure Bracketing; simple automated technique professional photographers use to ensure they properly expose their pictures, especially in challenging lighting situations; taking two or more pictures: one slightly under-exposed (usually by dialing in a negative exposure compensation, say -1/3EV), and the second one slightly over-exposed (usually by dialing in a positive exposure compensation, say +1/3EV).

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