FINDING THE RIGHT BLEND
Some deep-sky objects are brighter than others and to get the best photographic results from them, it’s necessary to be able to identify this and adjust your techniques accordingly. M13 is one of the best globular clusters visible from the northern hemisphere and falls into the bright category. Take too long an exposure of it and the core will overexpose to white. Expose correctly for the core and you’ll lose a lot of the outlying stars that really bring home just how huge this object is. A high dynamic range technique allows you to deal with this and see both.