High Dynamic Range

If you search websites for info on High Dynamic Range (HDR) you will find a plethora of opinions, examples, tutorials, and definitions.

For me, HDR serves two purposes: allowing a good image from one that would have otherwise had blown out hilites or shadows with no detail. Some scenes you will find yourself shooting have a range of lighting that your camera can’t capture in one image. If the sky, water, or other large part of the image is the problem, a Graduated Neutral Density filter might resolve the issue for you, but I prefer to take 3-5 images 1-2 stops apart in exposure and make an HDR image from them. It’s a matter of preference and I have nothing against filters; I just like the post shoot process using Bridge and Photoshop to edit my RAW images.

For most situations I encounter it seems that three shots, in 2 stopĀ  increments work best. If your camera allows you to bracket, with your camera in a tripod and in Aperture Priority mode, set it to take three shots varying the exposure by 2 stops. This will give you one shot at the exposure the camera would consider best, another at 2 stops below that, and one 2 stops above. (If you are not sure how to bracket with your camera, you may need to take a look at your user manual or search the WEB.) Why use Aperture Priority instead of Shutter Priority? Using Aperture Priority will keep the depth of field constant in your images, Shutter Priority may cause very noticeable differences because this mode results in your camera changing the aperture to get the correct exposure which will be problematic when you blend the images together later. Of course, you can use Manual mode also, but you still need to keep the aperture constant.

You need some type of software to do the HDR processing. Photoshop has a feature to create HDR images and there are many more products out there that will help you make great HDR images. My personal favorite is Photomatix. I’ve been using it for several years. I’ve downloaded trials of other software, but so far nothing has lured me away from Photomatix. If you are considering the purchase of HDR software, you might benefit from trying free trials of a few before you decide.

One thing I don’t like about using Photoshop is it reads the metadata in the images and if it can’t find it or if it detects that all of the images have the same exposure, it won’t let you procede. Sometimes I create three exposures from the same RAW file and Photomatix handles this very well.

Below are a couple of examples from photos I’ve taken recently. The first one was made using only one RAW image. I love the way Photomatix edited this image.

HouseSideCompare

The next photo was created from four different exposures 1 stop apart. Before I process the images in Photomatix I open them in Adobe Camera Raw to remove any chromatic aberration, make minor adjustments to extreme highlites and apply noise reduction. Photomatix will also take care of that, but I like the manual control I have in Camera Raw. I also use the ProPhoto RGB color space.

Here are the four original images:

exposresoldhouse

I could have gotten a good enough HDR image using the first three, but I wanted to capture the shadows in the upper part of the barn so I included the fourth, overexposed image to open those shadows.

Next step, opening in Photomatix:

OldBarnComparison

I hope this post will spark an interest and you will experiment with HDR. It’s a lot of fun and a great way to take your images to a new, artistic level. While it is better to take multiple images with your camera and use them, the example above shows what is possible if you think outside the norm when the need arises.

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