P.169 Changing the ISO Speed (Tip #001)

In digital photography, ISO is a measure of how sensitive the image sensor is to light. The lower the ISO value, the less sensitive it is, the higher, the more sensitive. The Canon Powershot S110 can take photographs in the range ISO 80-12,800. It is possible to select to either have the ISO setting chosen automatically by the camera (ISO Auto), or it can be set specifically by the photographer.

When a low ISO setting is used, the captured photo is of the highest definition. In situations where light is plentiful (e.g., bright sunny days), locking the ISO setting to the lowest possible value will generally get you the best photos. In situations where the lighting is less than perfect (dull days, or shooting indoors without flash), then a higher ISO setting will need to be used to avoid long shutter speeds and the risk of blurred shots. Instructions on Changing the ISO Speed appear on p.169 of the manual.

The Powershot S110 has the ability to have the camera automatically choose the optimum ISO setting within a specified range, and I recommend you consider using this. This is referred to on p.170 of the manual, under the heading Adjusting the ISO Auto Setting. Here you can choose the maximum ISO speed to be used in Auto ISO mode, in the range ISO 400 - ISO 1,600. I would recommend setting this to a middle value of say ISO 800 initially. When you've built up some experience of using your camera this will guide you as to the best setting in any particular situation. Work on the premise of attempting to shoot with a low ISO value unless you're unable to get the required shot, and then up the ISO setting.

From the shots that you've taken with your camera so far, interestingly I note that none seem to be at the lowest (ISO 80) setting of your camera. The following are examples of your photos taken using various ISO settings:

ISO 400 (Quite low ISO setting):

Here we see that the use of an ISO setting just a little above the lowest setting has nicely captured detail from Helen and Can's dining area. You and Helen are of course illuminated by camera flash. The increased sensitivity has meant background areas where the flash would not have reached are nicely exposed. The ISO not being too high has meant that the detail in the image is very high showing that at this ISO setting the camera performs exceptionally well.

ISO 1,600 (Medium ISO setting):

Many camera's begin to struggle at ISO setting of 1,600 and yet this is an excellent photo showing very high levels of detail. The photo benefits from the use of available light (rather than flash) which makes the background clearly visible and gives the photo a very natural look. The colour rendition of this photo is also very good.

ISO 12,800 (High ISO setting):

This is the highest ISO setting possible with this camera, and as expected, there is a noticeable drop-off in resolution. Since the shutter speed was 1/100, theoretically is would have been possible to take this shot at a lower ISO setting using a slightly slower shutter speed.

The use of the natural light from the window is once again very effective making this a very pleasing photo.

Note: I examined the ISO speed of your photos by using the Flickr option 'Actions/View Exif Info'.

P.S. The Canon Powershot S110's capability to handle low light through higher ISO settings is extremely impressive. Very superior to my Powershot S60 which you used on your recent holiday in England.