Most DSLRs have a Kelvin setting in the white balance options, and this can be set to the desired temperature. Older or less expensive models may not have this feature, in which case you will have to choose a preset white balance setting, usually either tungsten or daylight. As long as you are shooting RAW files, the white balance can be adjusted in postprocessing, but it is good practice to try to get the white balance close to the way you want it to look in-camera. Changing the white balance will change the appearance of the histogram, which can influence the way you determine exposure. high-iSo expoSure teSting Unlike film, digital sensors do not suffer from reciprocity failure. This makes high-ISO testing for long exposures a simple and effective way to determine the correct length of long exposures without waiting 10 or 15 minutes for a test shot at optimum ISO. By increasing your digital camera's ISO to the maximum setting and opening your lens to the widest aperture, you can take a well-exposed moonlight photograph in just a few seconds. This flexibility is enormously liberating and provides the opportunity to get a feel for a location by doing a series of quick handheld shots to assess the exposure, lighting, and framing of a shot without investing too much time. Most people can handhold a 2 or 3 second exposure steady enough to evaluate whether or not the scene merits a full-length exposure. When working in moonlight or other very low-light environments, temporarily raising the ISO and doing a short exposure and then translating it into a longer exposure at optimum ISO will save you a lot of time. Efficiency can be further increased by choosing test exposure settings that allow for second to