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HDR buildings - How to maximise dynamic range within your photos using HDR exposure and Photomatix.
To overcome this you can purposely create a photo with a high dynamic range. Here's how...
A high dynamic range photo, commonly shortened to HDR photo, is one that has been created using a special HDR feature found in Photoshop or purpose-made programs such as Photomatix.
The idea is to capture as large a range of exposures as possible when taking a photo. This is not possible with a single exposure, but you can take several photos and merge them with the HRD technique.
The Photo on the right shows the three bracketed exposures and then a merged version with a bit of artistic licence on the colour saturation and tonal range. You can create more subtle and natural looking version, but this style suits the shot.
Step 1: Mount the camera on a tripod
Set the camera up on a solid tripod. This is important to prevent any movement so the HDR program has an easier job of blending and there's not image shift which can cause poor results. If you don't already own a tripod check out Warehouse Express.
Step 2: Set the exposure
Switch the camera to aperture-priority mode or manual and have the aperture fixed. Take photos at different exposures, using exposure compensation if you're in aperture priority or adjusting the shutter speed in manual. To know what to set look through the lens while moving the camera around at different parts of the scene. If your camera has a spot meter mode switch to this so you can get a better indication of the various light levels. Take two or more photos at different readings from the darkest area to the lightest. In many cases you can get away with three exposures.
Step 3: Merge the bracketed photos
You should have a series of photos all from the same point all with the same aperture but showing different areas exposed correctly. Load these photos onto your computer and, if you're using Photoshop go to File> Automate>Merge to HDR, and choose the necessary bracketed photos. I will use Photomatix which has much better HDR processing capability and control. In this program select Generate HDR Image.
Click Browse and select the correct location of the photos from the explorer window. Right click on the list for each of the photos you are going to merge and click open and then OK on the "Selecting source images" box.
The program will then go to work pulling the chosen files in, merging them and creating a HDR image. And it's this bit that confuses people. A HDR image cannot be viewed on normal computer monitors. So the file that appears in the preview often looks rubbish. It's only if you click on an area and see the HDR viewer, that you see the real hidden depth.
Step 4: The processed HDR image preview
In the sample below I selected the side of the record player and it shows the power cables which you cannot see on the main pic. This is because the image is 32-bit colour depth and our monitors cannot show that detail information...yet. In future we will be able to display the entire range but for now we have to tone map the image.
Click Tone Mapping and here's where the fun starts. You are presented with a range of sliders to adjust the depth or the tonal range, the highlight and shadow cut off points and the colour saturation. When you first use this it can be quite daunting. You can also go overboard on effects.
Step 5: Tone mapping the image
Below is what I set to get a natural result that I mentioned at the beginning. It's picked out detail from the lighter exposure for the record player, and from the dark exposure for the window. And a mix of all three for other aspects. Notice none of the sliders are at the extremes of the scales.
And the next screengrab is a more experimental version which gives the characteristic cartoon feel that many enjoy creating when playing with HDR. This is the Marmite version - you either love it or hate it.
You can use HDR and tone mapping an a wide range of subjects as long as the subject is static. Have a go and let's see your results.