These days, just about every digital camera better than your iPhone has a user-selectable ISO range. While choice may be paralyzing, there's always the concern of image quality as well.
Since live music at indoor venues is often very dimly lit (by relative photography standards), I often get asked about what ISO I shoot at for live music photography, or what camera sensitivity I recommend for live music in general.
Here's my answer on what the best ISO sensitivity to use is for low light photography shot in any kind of photojournalism capacity.
Optimal Image Quality
For low light, high ISO work, there's really no such thing as “optimal” image quality. When there are constraints on lighting, time and position, it can feel as though almost every aspect of photography is one of compromise. Image quality is no exception – especially when you're shooting at the opposite end of the ISO range from a camera's “best” performance.
Blur or Noise?
Given the aforementioned technical constraints of live music photography, proper exposure for shows often comes down to a simple choice: Blur or noise?
This is essentially a consideration between using a lower ISO and compensating with a slower shutter speed, or using a higher ISO and a correspondingly higher shutter speed, albiet with the consequence of increased digital noise (and other drops in image quality associated with high ISO).
All things being equal, my personal take on this dichotomy is that I'll take noise over blur any day of the week. If high levels of noise is the worst thing someone can say about your images, then it means you did everything else right.
My Preferred ISO Settings
Personally, I prefer to shoot between ISO 1600 and 3200 whenever possible with my Nikon D3 and Nikon D700. The reason for this one-stop range is that it offers very high quality in terms of acuity, color fidelity and lower noise levels while still offering a good degree of “speed.” For the venues and types of lighting I shoot, this range of sensitivities generally works perfectly with my f/2.8 lenses.
That said, I also shoot above ISO 3200 whenever I need the speed for my work.
My very first “big break” image of Radiohead printed double-page in SPIN was shot at ISO 6400 with the Nikon D3. There's no concern of noise in print, even at a stop above my “sweet spot” range for that camera.
I've printed high ISO images shots (ISO 6400) from the Nikon D3 and Nikon D700 even larger, up to 20″ x 30″, and they look awesome.
The Best ISO To Use
Ultimately, the best ISO to use is the one that properly exposes your subject. Though it's beneficial to have a preferred, “go-to” range of ISOs that one uses under optimal conditions, we all know that low light photography is so often anything but optimal.
The main takeaway of this post is that there's no perfect or best high ISO setting.
If anything, I recommend shooting with and testing your camera at various settings and getting a feel for the quality that each setting will render. This will allow you to make the most informed choice based on the image quality required for the show, client and/or assignment.
Forget about a concern for noise, shadow detail or contrast – the best high ISO for you to use is the one that gets the job done. For almost all real world applications where you actually need high ISO performance, use whatever setting it takes.