How does the camera focus? at DVinfo.net

Chris Klidonas · August 25th, 2007, 10:12 PM

what does the camera use as a focus point? how does it decide? Is there a way to select a point of focus to use for tracking?

This is not about Instant AF or not, but in normal autofocus how many points does the camera have is it tracking or motion activated? how deos it know what you want in focus? obviously it does not promting the question, but is there a way to select say a middle or offcenter point as the point to continue focus on even if something else is in the frame or moving?

Mats Frendahl · August 26th, 2007, 01:51 AM

What I understand the focus point is Center.
I think one of the settings is to display the cross where it focus.
I don't think you can select focus point as you can on (Canon) SLRs.
For car rases you'd probl. want something like that but I don't think it's possible on the A1. Manual focus would be the option then.

Gert Kracht · August 26th, 2007, 04:12 PM

Look at the front side of your camera. On the left of the lens (if you hold the camera with the lens pointing towards you) you can see an electronice eye which sends out infra red light which bounces back from persons and subjects in front of the camera.
That light will bounce back to the centre of the lens and from there the electronics will pick up the signal and 'calulate' the focus.
The A1 sets it's focus in the centre of your video picture. If you want to have that different than switch to manual, use the manual focus button or the first ring at the front of the lens.

August 25th, 2007, 10:12 PM	#1
Chris Klidonas Regular Crew Join Date: Jul 2007 Location: NY, NY Posts: 129	How does the camera focus? what does the camera use as a focus point? how does it decide? Is there a way to select a point of focus to use for tracking? This is not about Instant AF or not, but in normal autofocus how many points does the camera have is it tracking or motion activated? how deos it know what you want in focus? obviously it does not promting the question, but is there a way to select say a middle or offcenter point as the point to continue focus on even if something else is in the frame or moving?

August 26th, 2007, 04:12 PM	#3
Gert Kracht Regular Crew Join Date: Feb 2007 Location: Ens, The Netherlands Posts: 198	Look at the front side of your camera. On the left of the lens (if you hold the camera with the lens pointing towards you) you can see an electronice eye which sends out infra red light which bounces back from persons and subjects in front of the camera. That light will bounce back to the centre of the lens and from there the electronics will pick up the signal and 'calulate' the focus. The A1 sets it's focus in the centre of your video picture. If you want to have that different than switch to manual, use the manual focus button or the first ring at the front of the lens. __________________ http://www.hdvinfo.nl The Dutch forum and website about HDV & Canon XH-A1

August 26th, 2007, 01:51 AM	#2
Mats Frendahl Regular Crew Join Date: Aug 2007 Location: Sweden Posts: 126	What I understand the focus point is Center. I think one of the settings is to display the cross where it focus. I don't think you can select focus point as you can on (Canon) SLRs. For car rases you'd probl. want something like that but I don't think it's possible on the A1. Manual focus would be the option then.