How to Lock Exposure on the Canon S90/S95

I’ve been using a Canon G10 as my everyday camera for the last few years. It’s a great camera, feels wonderful in your hand, lots of manual control – it’s like a mini-SLR. Unfortunately, it’s not a mini-enough SLR, so carrying it all the time is hard. This is the constant struggle with cameras, small enough to carry but with enough control to get the shots you want.

I’ve put my G10 on eBay and ordered the Canon S95 to replace it. I was originally planning to make the jump to the G12 (benefits: better low light performance and HD video), but the body size was still something I was struggling with.

The S90 really jumped out at me when it was released. I had an S30 about 10 years ago and was happy to see the S series return. The size is just right – big enough that you can treat it like a real camera, small enough that you can have it with you most of the time.

One of the guys at work has an S90 and I played with it a little. I really liked it, but couldn’t find the * button (Canon’s exposure lock button). That’s the thing I use more than anything on my SLR and G10 to try to quickly get the shot I want (without too much fiddling of settings, etc.).

On Friday, we figured out how to do it. The S90 (and S95) have a customizable button that can be assigned to one of a number of different functions, one of them is AE – auto exposure lock.

Auto Exposure Lock is a surprisingly useful tool that really expands what the photographer can do to apply exposure control, without losing the convenience and working speed of automatic exposure. In many cases, using it requires little more than identifying an element in a scene that you’d like to concentrate upon, aiming the camera at it and pressing the rear AE Lock button, and then re-composing to get the framing you want. It can lead to more consistent exposures when you’re shooting a sequence of shots, and is ideal for shooting with a primary subject off-center. It’s a great thing to get familiar with, so that you’re ready to use it when an opportunity presents itself.

This is what I’d been looking for when playing with the S90, but I hadn’t found it – nor had anyone else on the team. With this set as the custom button, I can treat an S90/S95 like a mini SLR (or the G series) when trying to compose a scene.

So there you have it – something you might have known already if you’d read the manual. My S95 is on order, so I still have an excuse.