In those early days, when all I had was an analog SLR, I had to make choices up-front. Do I buy an ISO 100 film for daytime shooting? (It’s cheaper, besides.) Do I go in for the expensive ISO 1600 film for my fancy night shots? Do I lug around the tripod? Do I use the flash? Do I even bother taking indoor shots? etc.

With my new digital camera, at least the ISO choice vanishes. The ISO range varies from 64 to 1600. And so, I don’t need flash or a tripod most of the time.

But once in a while, I get into a tricky situation.

Having a digital camera lets me take pictures a lot faster. Suppose I spot a boat speeding by when strolling along the Thames. The time it takes from the instant I see it to the instant I click the shutter is about 5 seconds. 2 seconds to pull out the camera, 1.5 seconds for the camera to start up, and about 1.5 seconds for me to aim and shoot.

I love being able to do this kind of a thing.

Except, it’s still a bit tricky managing the ISO. It takes me about 10 seconds to change the ISO settings. No, not because the menus are complex… that accounts for only about 3 seconds or so. The bulk of it is because I have to think about what ISO setting to use – especially given that I like to overexpose digital camera images a bit.

So, when I’m going indoors, I have to remember to set the ISO to something like 400 or 800, and back again when I get out. It may sound like I’m going a too far, but the thing is, since I don’t keep my tripod always attached, and don’t ever turn on the flash, I’ve spoiled a fair number of impulsive indoor and night shots because I’ve had the wrong ISO setting at the wrong time.

Being digital images, many of these problems can be fixed.

If I use a high ISO setting (say ISO 800), I get a fair bit of digital noise. But NeatImage does a decent job of reducing noise (thanks, Dhar!), so the result is not too bad.

If I use a low ISO setting (say ISO 100), I get clean images in bright light, but blurred images in low light (no tripod, no flash, you see). I haven’t found anything that can recover from a blurred image.

I decided, on the balance, to have a slightly higher ISO setting by default. I get slightly noisier images, but that’s less of a worry.

So I leave the camera in ISO 400. I can quickly shoot indoors. If I have the time and need, I shift to ISO 100, or use a tripod if required. Then I set it back to ISO 400 when done.