I honestly think too many people are caught up on the "must shoot with the lowest ISO possible" scenario. Instead of being caught up in the technical mumbo jumbo everyone needs to remember that a photograph is art and the photographer is a painter.
Each photographer has their own style, some you may like and some you may not. I hear people complaining all the time about an image being too noisy and using noise reduction software to fix it. Don't get me wrong, its not that I dont agree with it because I used one myself but when someone runs across an image that is "too noisy" they trash it.
Having noise in your image to me gives the feeling of a timeless moment and depending on the subject and look your going for don't be afraid to crank up the ISO and see how creative you can get.
I just recently picked up a 50D and it's capable of ISO 12800.. I decided to play around with it and see what I could come up with. As I said, get creative and create art that you are happy with, not everyone else (excluding clients).
All of these shots were taken at ISO 12800 on the 50D...
In traditional (film) photographyISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films – 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.
Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain. Higher ISO settings are generally used in darker situations to get faster shutter speeds (for example an indoor sports event when you want to freeze the action in lower light) – however the cost is noisier shots.
100 ISO is generally accepted as ‘normal’ and will give you lovely crisp shots (little noise/grain).
Most people tend to keep their digital cameras in ‘Auto Mode’ where the camera selects the appropriate ISO setting depending upon the conditions you’re shooting in (it will try to keep it as low as possible) but most cameras also give you the opportunity to select your own ISO also.
When you do override your camera and choose a specific ISO you’ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example – if you bumped your ISO up from 100 to 400 you’ll notice that you can shoot at higher shutter speeds and/or smaller apertures.
When choosing the ISO setting I generally ask myself the following four questions:
- Light – Is the subject well lit?
- Grain – Do I want a grainy shot or one without noise?
- Tripod – Am I using a tripod?
- Moving Subject – Is my subject moving or stationary?
If there is plenty of light, I want little grain, I’m using a tripod and my subject is stationary I will generally use a pretty low ISO rating.
However if it’s dark, I purposely want grain, I don’t have a tripod and/or my subject is moving I might consider increasing the ISO as it will enable me to shoot with a faster shutter speed and still expose the shot well. Of course the trade off of this increase in ISO will be noisier shots.
Situations where you might need to push ISO to higher settings include:
- Indoor Sports Events – where your subject is moving fast yet you may have limited light available.
- Concerts – also low in light and often ‘no-flash’ zones
- Art Galleries, Churches etc - many galleries have rules against using a flash and of course being indoors are not well lit.
- Birthday Parties – blowing out the candles in a dark room can give you a nice moody shot which would be ruined by a bright flash. Increasing the ISO can help capture the scene.
ISO is an important aspect of digital photography to have an understanding of if you want to gain more control of your digital camera. Experiment with different settings and how they impact your images today.
