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Distance-metering and eye focus.
In the beginning there was optical film. It was not even that long ago and my friend bought a Canon Eos 3 (or 5, my memory deludes me)..

Anyway his camera had:1. IR sensors to measure distance for the AF.and.

2. A pupil sensor in the viewfinder so that the camera focused on where-ever he looked..

Am I wrong or do these things not exist any longer in even today's top digital models and if so why??..

Comments (12)

1. IR sensors to measure distance for the AF..

There is no infra-red sensor. The AF assist light just provides illumination that the normal AF system can use in low light..

But you're right, the current generation of cameras doesn't have it built in. You have to use a Speedlite flash to get this..

And2. A pupil sensor in the viewfinder so that the camera focused onwhere-ever he looked..

Yep. Some love it, some don't get on with it, but nobody understands why Canon hasn't implemented this on today's high-end cameras...

Comment #1

Steve Balcombe wrote:.

1. IR sensors to measure distance for the AF..

There is no infra-red sensor. The AF assist light just providesillumination that the normal AF system can use in low light..

But you're right, the current generation of cameras doesn't have itbuilt in. You have to use a Speedlite flash to get this..

But why? I hate the help-light (I much rather focus manually). In dark situations it disturbs the subject or exposes me..

And2. A pupil sensor in the viewfinder so that the camera focused onwhere-ever he looked..

Yep. Some love it, some don't get on with it, but nobody understandswhy Canon hasn't implemented this on today's high-end cameras..

Ah, so this has never existed in oter cameras than Canon? Now they're talking about gazillions of AF-points instead, but with this technique there's no limit...

Comment #2

Rodluvan wrote:.

Ah, so this has never existed in oter cameras than Canon? Now they'retalking about gazillions of AF-points instead, but with thistechnique there's no limit..

The reason people didn't get on with it was because it was impossible to examine the shallowness of Depth of Field. Every time the eye tried to check blurriness in a fuzzy image area, the camera promptly cancelled it's previous focus point and RE-focused that blur into sharpness..... (Grrrrrrr!!).

In short, it was a beautiful implementation of an idea that was totally wrong-headed right from the start. I would be very surprised if we ever saw it return.Regards,Baz..

Comment #3

Like face detection - who NEEDS it. Most photos I take have people in it, but they are not the main subject... Well, at least you can turn off face detection. Right?.

The greatest of mankind's criminals are those who delude themselves into thinking they have done 'the right thing.'- Rayna Butler..

Comment #4

Rodluvan wrote:.

Steve Balcombe wrote:.

1. IR sensors to measure distance for the AF..

There is no infra-red sensor. The AF assist light just providesillumination that the normal AF system can use in low light..

But you're right, the current generation of cameras doesn't have itbuilt in. You have to use a Speedlite flash to get this..

But why? I hate the help-light (I much rather focus manually). Indark situations it disturbs the subject or exposes me..

The near-IR put out by an external flash is the same as the near-IR put out by an on-body emitter. It doesn't disturb the subject..

Perhaps you are thinking about the multiple quick flashes of the flash head used for AF assist with the built-in flash. That's quite different..

2. A pupil sensor in the viewfinder.

Yep. Some love it, some don't get on with it.

Ah, so this has never existed in oter cameras than Canon? Now they'retalking about gazillions of AF-points instead, but with thistechnique there's no limit..

Yes, only Canon has it. They still sell a film camera with this feature, but have not yet done this on a digital camera..

Seen in a fortune cookie:Fear is the darkroom where negatives are developed..

Comment #5

Barrie Davis wrote:.

The reason people didn't get on with it was because it was impossibleto examine the shallowness of Depth of Field..

If your work flow has you always checking DOF, turn it off..

I would be very surprised if we ever saw it return..

I would be very surprised to see it return, because it hasn't left:.

Http://www.bhphotovideo.com/...roduct/335576-USA/Canon__EOS_Elan_7NE_Kit.html.

I'm a bit more surprised that it hasn't made it into a DSLR yet..

Seen in a fortune cookie:Fear is the darkroom where negatives are developed..

Comment #6

GodSpeaks wrote:.

Like face detection - who NEEDS it..

If you are taking portraits or candids where you do want to focus on a face, having some way for the AF system to get face-priority is a good thing. ECF and face detection are two ways to do it. The other ways (center focus point and recompose, mess with dial to get the correct focus point) either don't work as well or are cumbersome..

But if your camera has ECF and/or face detection and you don't want those features, simply turn them off..

Seen in a fortune cookie:Fear is the darkroom where negatives are developed..

Comment #7

Rodluvan wrote:.

Steve Balcombe wrote:.

Yep. Some love it, some don't get on with it, but nobody understandswhy Canon hasn't implemented this on today's high-end cameras..

Ah, so this has never existed in oter cameras than Canon? Now they'retalking about gazillions of AF-points instead, but with thistechnique there's no limit..

I don't think it gives you unlimited focus points; the camera is just selecting the focus point nearest to where you are looking..

Steve..

Comment #8

Steve Ives wrote:.

I don't think it gives you unlimited focus points; the camera is justselecting the focus point nearest to where you are looking..

Yep, as currently implemented..

It should be possible to do "unlimited" (in quotes because of course there is a limit the resolution of the sensor reading your eye, or failing that the resolution of the image sensor) focus points with a camera using contrast detect AF (i.e. a digicam with EVF)..

Seen in a fortune cookie:Fear is the darkroom where negatives are developed..

Comment #9

Nickleback wrote:.

The near-IR put out by an external flash is the same as the near-IRput out by an on-body emitter. It doesn't disturb the subject..

The AF assist on my 430EX is extremely visible! Visible red, not near-IR.

Perhaps you are thinking about the multiple quick flashes of theflash head used for AF assist with the built-in flash. That's quitedifferent..

I think you must be referring to the modelling flash which can be obtained by pressing the DoF preview button..

No doubt other systems work differently, but that's what my Canon flash does...

Comment #10

Steve Balcombe wrote:.

Nickleback wrote:.

The near-IR put out by an external flash is the same as the near-IRput out by an on-body emitter. It doesn't disturb the subject..

The AF assist on my 430EX is extremely visible! Visible red, not near-IR.

The lower 1/3 of the near-IR spectrum is visible, and is, in fact, bright red. It doesn't bother subjects much. The near-IR emitters on flashes isn't much different than the near-IR emitters on earlier EOS bodies, they're just more powerful, cover more points, and are less easily blocked by fingers, lenses or lens hoods..

Perhaps you are thinking about the multiple quick flashes of theflash head used for AF assist with the built-in flash. That's quitedifferent..

I think you must be referring to the modelling flash which can beobtained by pressing the DoF preview button..

Nope, the AF-assist from the built-in flash. Which is quite similar to the strobing during DOF preview..

No doubt other systems work differently, but that's what my Canonflash does..

Other flashes work similarly..

Seen in a fortune cookie:Fear is the darkroom where negatives are developed..

Comment #11

Nickleback wrote:.

The lower 1/3 of the near-IR spectrum is visible, and is, in fact,bright red. It doesn't bother subjects much. The near-IR emitterson flashes isn't much different than the near-IR emitters on earlierEOS bodies, they're just more powerful, cover more points, and areless easily blocked by fingers, lenses or lens hoods..

Well, if it's technically correct to call that near infra red then I stand corrected, but mine (on the 430EX) is very bright..

I have a Canon film SLR (EOS 10) so I'm familiar with the built in red AF assist. Yes, it's too easy to block it by mistake, but it worked ok and was much less intrusive. More importantly it worked without popping up the flash..

Perhaps you are thinking about the multiple quick flashes of theflash head used for AF assist with the built-in flash. That's quitedifferent..

I think you must be referring to the modelling flash which can beobtained by pressing the DoF preview button..

Nope, the AF-assist from the built-in flash. Which is quite similarto the strobing during DOF preview..

Well, I try to make a point of learning something every day and today's nugget was that the built-in flash provides AF assist. Somehow that fact had escaped me. Memo to self - RTFM...

Comment #12

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