Idiot question alert - 52 focus points

Started Jan 2, 2014 | Questions thread
SergioSpain Contributing Member • Posts: 539
Re: Pretty simple actually ...

Grevture wrote:

Well, in most cases you want to be able to do both. That is why we have options like matrix exposure where the camera makes lots of measurements and analyze the result in various ways, and also simple spot metering where you measure at one point only.

Focusing works pretty much the same. Sometimes you just want to measure in one spot and completely ignore what is going on around that spot. Sometimes you want to measure over a smaller area, and ignore things outside that area. And sometimes you want to measure over a larger area and figure things out from all that information.

That's a bit misleading though. You can take an average exposure reading and shoot with that, but there's no such thing as an average focus reading. And if there were, it wouldn't work in most cases! If you have all 51 points active, it doesn't mean that the camera is using focusing information from all the points. It means that if the subject is moving, the camera can try to track it and keep it in focus using one of the 51 points. The various points can also be used for predictive tracking to predict where the subject will be and where the focus will be when the shutter is triggered. But again, there is no such thing as average focus.

 SergioSpain's gear list:SergioSpain's gear list
Nikon D700 Nikon D4 Nikon AF-S Nikkor 70-200mm f/2.8G ED VR Nikon AF-S Nikkor 14-24mm f/2.8G ED Nikon AF-S Nikkor 300mm f/2.8G ED-IF VR +5 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow