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?
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Well, the speed of your autofocus depends on a variety of different factors. Lighting conditions, subject contrast, lens, focal range, af drive, af sensor type and processor speed are those I’d consider of the top of my head.
AF works slower in low light or low contrast situations because the camera has a harder time to figure out when the image is sharp. Lenses with a large focal range (like 150-600mm) need time to move the focus through that range, that’s why they often have range limiters for quick focusing. Ultrasonic AF drives are generally faster and quieter than “traditional” drives. Mirrorless cameras focus using the captured image and software and need good processors to get a quick focus. DSLRs rely on specialised focus sensors.
Setting up a common test, eliminating all possible outside errors and testing a wide variety of cameras with an even wider variety of lenses seems unnecessary given that even most mid range cameras should have a pretty snappy focus these days.
Thank you for elaborating.
most mid range cameras should have a pretty snappy focus these days.
What would you consider ‘mid range’ in this context?
No problem.
I’d consider a 500€ camera to be in the mid range for hobbyists cameras. For example anything in the Canon X00 line really, like 800D or 850D.
What I would do is watch as many YouTube videos as you can of someone either testing or using the camera. I find it much easier to actually see the camera in use to be able to understand the performance of the camera better. Numbers don’t mean anything to me 😕
