Fastest focusing clothing - bare with me on this one

SamJT

SamJT

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Sam
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Disclaimer - I don't know much about the ins and outs of the focusing system on your average DSLR

...however as far as I'm aware they focus based on detecting an area of high contrast. I take photos of mountain bikers and theres nothing worse than someone riding in green/dark kit in a dark wood, but a red tshirt can make the difference, both with the final photo and it seems with the focusing.

So basically, I was wondering if there would be an optimum tshirt design to maximise focusing accuracy for sports photography? Something like a large chequered black and white or something similar? Does the colour standing out from the background actually make a difference? Just curious really, got no idea what the answer is!
 
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As you know, focus is based on detecting an area with contrast,
so colours are irrelevant as long as the system can read a good
difference in luminosity. To detect lower contrast one will need
higher luminosity as higher contrast will not.
 
White T-shirt, with random bold black markings.
 
Obviously you can't get mountain bike riders to do this, but Roger Hicks once suggested you get your model to hold an item with a bar code on and focus on that.


Steve.
 
If you could get a rider to wrap a bit of sticky reflective tape round the handlebar stem, and you used a small weak unfocused light like a diffused head torch, of negligible effect on the general image, it would selectively brighten up the reflective patch, like a distant road sign catching off-beam spill from car headlights. A tiny pin point LED on the handlebars could also provide a focusing point.
 
I always find in dark light that the focussing works best on detecting the edge between light and dark points.
Realistically though why not go manual. Turn off the auto focus and prefocus on the point the rider is going to be.
 
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