I’m looking for an amateur (≤ €500) digital camera for my dad. The main issue I’d like to alleviate is the slow autofocus on his current one. On his (and my very old, very cheap camera), the autofocus takes about a second, sometimes even more to find the right focal length. He laments that he’s unable to take a quick snapshot of a fleeting moment due to this.

I initially hoped I would find some metrics on this in cameras’ technical specifications. But so far, none have turned up. Guides often critique or praise the autofocus feature, but don’t provide a sense of how quickly the lenses adjust, either.

This leads me to these questions I now put to you to judge: Am I naive to expect a single number to adequately represent the amount of time the autofocus needs to focus? What contributing factors would render such a metric irrepresentative, if it existed?