Ah, "Face Detection". One of the newest of the consumer buzz words.
In a perfect world, face detection would:
1) Seek and find human and animal faces, determine the distances to all faces and set an appropriate f-setting to make sure that all faces were in focus.
2) Use the faces to help track subjects as they cross the image frame to assist the AI-Focus algorithms calculate and maintain focus in a motion situation, either subject to camera or camera to subject.
3) Use the face-distance information to regulate flash output, regardless of the subject position in the frame.
4) Avoid AF distractions of foreground and background objects and concentrate focus priority on the faces in the image. This allows more accurate AF using multi-point focus automation.
In Canon technology this all started with the Digic III processor for small cameras but I believe that only the dSLRs using Digic IV offer face detection.
In the "real" world, face detection works "some" of the time. It is not something I consider a professional advantage, but it does ease the person moving from a P&S into the dSLR world. You can use face detection to "assist" by half-depressing the shutter button and then watching the LCD display to confirm that all faces have been recognized and accounted for.
Since face detection only works in live view mode, and since it's both a little slow and uncertain, I regard it as something of a novelty (5D MKII). It does work better in certain lighting conditions than the "Live Mode" AF however.
Ah, "Face Detection". One of the newest of the consumer buzz words.
In a perfect world, face detection would:
1) Seek and find human and animal faces, determine the distances to all faces and set an appropriate f-setting to make sure that all faces were in focus.
2) Use the faces to help track subjects as they cross the image frame to assist the AI-Focus algorithms calculate and maintain focus in a motion situation, either subject to camera or camera to subject.
3) Use the face-distance information to regulate flash output, regardless of the subject position in the frame.
4) Avoid AF distractions of foreground and background objects and concentrate focus priority on the faces in the image. This allows more accurate AF using multi-point focus automation.
In Canon technology this all started with the Digic III processor for small cameras but I believe that only the dSLRs using Digic IV offer face detection.
In the "real" world, face detection works "some" of the time. It is not something I consider a professional advantage, but it does ease the person moving from a P&S into the dSLR world. You can use face detection to "assist" by half-depressing the shutter button and then watching the LCD display to confirm that all faces have been recognized and accounted for.
Since face detection only works in live view mode, and since it's both a little slow and uncertain, I regard it as something of a novelty (5D MKII). It does work better in certain lighting conditions than the "Live Mode" AF however.
In other (more cynical) words, a gimmick. Got it. I think I'll wait for Ziggy's implementation.
... You can use face detection to "assist" by half-depressing the shutter button and then watching the LCD display to confirm that all faces have been recognized and accounted for.
...
I misspoke here, the face detection is not activated with the shutter button half-depress, it is on all the time. You can guide it somewhat with the joystick but it appears to be a single point focus acquisition.
I suspect it might work rather well for snapshots and close ups shot, like candids, in a party. Where you are shooting 1 to 3-4 faces in a group that covers much of the sensor.
I suspect is searches for eyes - twin dark spots in a lighter tone, possibly Caucasian tone, background, or something like that.
I think it's for those who treat dslrs as a bulky and rather expensive P&S.
If you start thinking of it, a whole plethora of questions rises:
you're shooting in a crowd. There are faces everywhere, close, far, black, white. All lit nearly identically. Which one *face* will a camera focus at?
you're shooting a closeup headshot at extremely shallow DOF. Which eye will it focus at?
and so on and so forth
I say: fuggedaboutit
Yeah, I'm getting the idea that it's a refinement of the DOF priority mode on my 20D. It sounded cool at first so I played around with it, but basically all it did was select a ridiculously small aperture most of the time. I don't need a DIGIC processor to tell me f/22 will give more DOF than f/4.
Comments
In a perfect world, face detection would:
1) Seek and find human and animal faces, determine the distances to all faces and set an appropriate f-setting to make sure that all faces were in focus.
2) Use the faces to help track subjects as they cross the image frame to assist the AI-Focus algorithms calculate and maintain focus in a motion situation, either subject to camera or camera to subject.
3) Use the face-distance information to regulate flash output, regardless of the subject position in the frame.
4) Avoid AF distractions of foreground and background objects and concentrate focus priority on the faces in the image. This allows more accurate AF using multi-point focus automation.
In Canon technology this all started with the Digic III processor for small cameras but I believe that only the dSLRs using Digic IV offer face detection.
In the "real" world, face detection works "some" of the time. It is not something I consider a professional advantage, but it does ease the person moving from a P&S into the dSLR world. You can use face detection to "assist" by half-depressing the shutter button and then watching the LCD display to confirm that all faces have been recognized and accounted for.
Since face detection only works in live view mode, and since it's both a little slow and uncertain, I regard it as something of a novelty (5D MKII). It does work better in certain lighting conditions than the "Live Mode" AF however.
Moderator of the Cameras and Accessories forums
Thanks.
I misspoke here, the face detection is not activated with the shutter button half-depress, it is on all the time. You can guide it somewhat with the joystick but it appears to be a single point focus acquisition.
Moderator of the Cameras and Accessories forums
It is neat watching the square move around following a face, just neat and fun.
Of course i have not really used live view mode either.
I suspect it might work rather well for snapshots and close ups shot, like candids, in a party. Where you are shooting 1 to 3-4 faces in a group that covers much of the sensor.
I suspect is searches for eyes - twin dark spots in a lighter tone, possibly Caucasian tone, background, or something like that.
Moderator of the Technique Forum and Finishing School on Dgrin
If you start thinking of it, a whole plethora of questions rises:
- you're shooting in a crowd. There are faces everywhere, close, far, black, white. All lit nearly identically. Which one *face* will a camera focus at?
- you're shooting a closeup headshot at extremely shallow DOF. Which eye will it focus at?
- and so on and so forth
I say: fuggedaboutitYeah, I'm getting the idea that it's a refinement of the DOF priority mode on my 20D. It sounded cool at first so I played around with it, but basically all it did was select a ridiculously small aperture most of the time. I don't need a DIGIC processor to tell me f/22 will give more DOF than f/4.