Photo by Laura Burlton...
A beautiful photo by Laura Burlton. It's difficult to get good photos at milongas because of the low light conditions - especially of an orchestra - violinists "bowing" and moving their arms.
Laura used a Canon EOS-1D Mark II-N shooting at ISO 1600 (high ISO, but very low noise), 1/40th of a second (about as slow as you can go hand held, f1.2 which is about the fastest lens you can buy. ("f" stop is related to the exit diameter of the lens, the smaller the "f" number, the larger the opening, the more light that is allowed into the CMOS sensor).
The low noise at high ISO is one of the attributes that makes these cameras so expensive - hers probably ran about $4,000 a few years ago...the newest ones run inthe $5k to $8k range. It's just better technology - but it costs more. "Noise" in digital photography is like "grain" on film. Shooting a high ISO (ASA back in the olden days) film and pushing it in the darkroom would yield a very fuzzy/grainy negative. Here, the RAW file (digital "negative") yields a very fine "grained", low noise photo.