Shooting for HDR

HDR. It is not your typical grunge HDR anymore. HDR (High Dynamic Range) imaging can represent anything from artistic grunge to an image that no one will recognize as HDR. The premise of HDR is combining multiple images so the information from the dark areas is not all black and the information from the light areas is not blown out white. Digital cameras can record a range of light of about 6-8 stops (depending on who you talk to and the camera). Slide film records about 5 stops of light. So what happens when you have a scene that has lights and darks outside of the range that can be recorded? Well, in a single shot, you have to decide whether to record and emphasize the lights ( while not blowing them out) which will create very dark areas. If you emphasize the dark areas (record them so there is detail in the darks) you will sacrifice detail in the light or white areas (blow the highlights out).

What do you do if you want to see detail in the highlights and detail in the shadows and the range of light is greater than 6-8 stops? Voila’, HDR. In the old days, we would simulate HDR by combining elements of several different images (shot to preserve detail in highlights, then to preserve detail in shadows) in Photoshop. This was a time consuming task. Enter HDR software. Now you just shoot multiple images at different exposures and then the magic of HDR software combines them. I will talk about NIK HDR Efex Pro in a later post as my HDR software of choice.

Shooting HDR.

First, see if you scene needs HDR. You can use the spot meter in your camera to spot on the darkest area and then the brightest area and compare the exposures. If they are more than 6 stops apart, HDR will work for you. After some experience, you can take a single image and look at the dark areas and the bright areas and judge for yourself whether HDR will help. Don’t forget that post processing with Lightroom or Photoshop can help bring back detail in highlight areas and bring out detail in shadows without HDR.

Once you have decided to shoot an HDR, compose your scene with the camera on a tripod. Since you are combining 5 or more images, you don’t want the camera to move. Set your exposure just like you would for a normal shot. Shoot an image of your hand (this is to give you a reference point of beginning and end for finding components of HDR images). Then set your camera to bracket 1 stop apart and for 5 shots. I will occasionally use only 3 images but they need to be 2 stops apart, or 7 images that are one stop apart. Shoot your brackets. Remember to turn bracketing off, and then shoot an image of your hand to complete the series.

It is not hard to do. Remember that you will be combining multiple images, so movement within the image (people, wildlife, etc) can cause a ghosting or multiples but software is getting good about managing this. I shoot running water all the time (streams, waterfalls) and HDR gives me a look that is different than the straight single image. Play with this and then you will be able to add this trick to your bag of techniques.

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