The ability to shoot in low light situations can be crucial to a photographer.  Sometimes the use of flash just isn’t possible or isn’t permitted.  In these situation, we rely on two things.  The first is fast glass with wide apertures (2.8 or more), and the second is higher iso.  Each has it’s own drawbacks.  Shooting at wide open apertures can lead to soft or out of focus images due to the narrow depth of field.  Shooting at higher iso level tends to increase the amount of noise in the image.  Noise can be controlled to a degree if proper exposure is obtained. (more…)