Hello. In today's lesson, we'll examine what HDR is, how to shoot HDR images and prepare them for processing in Lightroom. HDR is an acronym for High Dynamic Range. While most cameras could capture a pretty good range of tones from dark to light, the human eye could perceive much more. This dynamic rage could be simulated by capturing multiple exposures of a scene that retain the maximum shadow and highlight detail. These exposures are combined to simulate the extended tonal range that the human eye perceives. It's particularly effective in scenes with high contrast or extremes of highlights and shadows such as sunrise, sunset, night scenes, and bright cloudless days with full sun creating deep shadows and bright highlights. Since you are making several exposures of the same scene it will be merged together into one image, several recommendations should be followed. First, choose a scene such as a landscape where little movement of the subject will occur between exposures which could result in a ghosting or poor alignment of the images. Use a tripod, set your camera to its lowest ISO and use the raw format and manual mode. The lowest ISO will record the greatest dynamic range your camera could capture. In raw formats capture up to 16 bits of information which significantly greater range than JPEGs produce. Ideally keep the same aperture for all photos as this can affect up the field. And determine the exposures you want to meet for the shadows in one capture as shown here, highlights in another, in this image here, and mid-tones for an average exposure here. This will create what is known as a bracket. This bracket could contain as few as two exposures or as many as seven, ranging from the darkest to the lightest. The greater the brightness range of the original scene the more exposures required for optimal results. If your HDR bracketing is less than three stops in total separation, meaning minus one and a half stops zero and plus one and a half stops difference, use only the darkest and brightest exposures to generate an HDR. Capturing the middle exposure or zero exposure isn't necessary to generate a quality exposure blend in such cases. If you exceed this three-step separation between darkest and brightest exposures, an additional exposure offset becomes necessary to produce a good quality HDR photo. Here's what will work best for Lightrooms merge to HDR. If you bracket -1.52 to +1.5 in your exposure range, you could get by with this little two exposures. If there is a three-star difference between the two, 3 to +3 then you can use three exposures. If there is 41/2 stops difference on either side plus or minus, you can use four exposures. And if there are six stops on either side you can use five exposures. Typically speaking, if you are using the plus or minus one and a half exposure bracket you can often ignore the middle exposure. This helps Lightroom render faster and improves alignment and the result of HDR by reducing the chance of potential camera movement between the exposures. However, the middle exposure can be useful when the scene is within the acceptable range of a single exposure that could have been developed independently such as this scene here. If you are a standard HDR shooter using a plus or minus two stop bracket, you ideally require only three photos to merge into an HDR. In a five shot or four stop different exposure you can now drop from five shots to four shots to merge. And the seven shot can drop to five shots as we discussed earlier. Keep in mind that when you take photos to be combined in an HDR photo, some cameras allow automatic exposure bracketing. This would be ideal if you have that, it will take care of the bracket for you. In my case, these were captured manually. So the first underexposed image slightly exposed for the shadow areas. The first image exposed for the highlight areas minus one, one second, then a middle exposure of two seconds and the shadow exposure of four seconds which basically translates to one f-stop difference between each exposure. And because it is more of a scene it could be captured in a single exposure, I did include the middle one in this instance. So in this lesson, you've learned what HDR is, why you would use it and how to capture images using it for optimal results. Thanks for watching. Stay tuned for the next lesson where we will process in HDR, high dynamic range image using the HDRMerge command and perform some additional creative processing. So let's go check it out.
