• grist-mill-at-mohican-state-park_10112009_004-006_hdrpro_nocp

    As I discussed in part one, there are often scenes we want to take a picture of but the contrast between the lightest parts and the darkest parts are too much for the camera to capture in one shot unless we manipulate something.  The first way I mentioned was to use graduated neutral density filters at the time of capturing the picture so that it can be done with one shot.

    In the next several articles, I will discuss several ways to use multiple images to create a single picture.  First you will need to use the histogram on your camera to be sure you capture enough shots to show all the dynamic range.

    You want do what is called “bracketing”.  Bracketing is where you will take a series of pictures, adjusting each one so the exposure is a little lighter or darker than the recommended exposure.  Typically I place my camera on the manual setting so that I can make the adjustments of shutter speed and aperture myself.

    I snap my first exposure for what the camera recommends and then look at my histogram.  If I see that the highlights are blown out to the right, I will adjust my controls to darken the exposure one f-stop and then take another shot.  Checking the histogram again, I will look to see whether my highlights reading is still smashed against the right or did the highlights get pulled back off the right side.  I will keep repeating this process until I have an exposure showing the highlights moved from the right side.

    over-histo

    In the same way, I will adjust the left side of my exposures from the first shot for the shadows.  Trying to make sure I have an exposure that shows the shadows not against the left side of the histogram.  Typically you could need any number from three to six exposures to capture the full dynamic range of some scenes.

    under-histo

    Now that we have our series of bracketed pictures, we can load them into different software programs to merge them into one picture showing the whole spectrum of dynamic range.

    Today’s method is using Merge to HDR Pro in Photoshop.

    1. In Photoshop go to File > Automate > Merge to HDR Pro.
    2. Click on the Browse Button in the dialog box and select the images you want to merge together. Once selected and loaded, click on the Ok button to start the merging process.
    3. When another window opens showing a merged picture, I click on Remove Ghosts, leave the mode at 32-bit, and then click on Tone in ACR.
    4. From here I do some global processing and click Ok. This takes the adjusted image back to the Photoshop window and made the layer a Smart Object with the ACR adjustment layer connected below.
    5. Next I go to Image > Mode > 16-Bit to convert the 32-bit file to a 16-bit file. When the little box comes up, click Merge.
    6. In the next box, I set Detail and Saturation to zero and click Ok.
    7. Now you can continue making any other adjustments to the picture for final processing.

    Here are the three pictures I used to create the image at the top of the article.

    grist-mill-at-mohican-state-park_10112009_005 grist-mill-at-mohican-state-park_10112009_006 grist-mill-at-mohican-state-park_10112009_004

    Any comments or questions can be posted in the Comment section below.