Focus Confirmation & Focus Triggered Shutter

[Einst_Stein]

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AF M system is likely impossible, but a M body with focusing confirmation and focus triggered shutter release should be easy.

 

Here is the proposal:

 

1. When focus confirmation is enabled, the view finder will show a sign with a flashing light if the target in the focus point is in focus.

2. When focus triggered shutter release mode is enabled, the M body will fire the shutter when the focus is confirmed.

3. the focus triggered shutter mode is enabled either by the manual wheel or buttons, or pushing 2/3 of the shutter release button. yes, the shutter release button then can be pushed 1/3 of the way or 2/3 or all he way down. pushing all the way down will unconditionally fire it, 1/3 will lock the exposure, 2/3 will be shutter standbythat will fire if the focus is confirmed.

4. focus bracketing; user can setup focus bracketing through the pulldown manual, so that the shutter release can fire multiple times according to the bracket tolerance. for example, if the focus bracket range is 1 inch with 5 exposure, the shutter will fire when the focus error is -2,-1 , 0, 1, 2 inches.

[250swb]

At the moment such an idea would suppose that everything you want in focus is always in the centre of the frame, because that is where the focus point is. But I suppose it is some peoples idea of 'composition'.

 

Steve

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[TomB_tx]

I have a dSLR that has similar "catch-in-focus" that some users rave about. I'd much rather just focus myself manually and trip the shutter when I want. I've never found a "focus confirmation" aid that is as accurate as I am - even with my old eyes.

[dbraid]

The devil is always in the details on a scheme such as this. For example, what happens when you are at f8. How "in focus" is "in focus"? Further, how precise in area is the focus point? I often find that I focus on one aspect of what is within the patch of my RF. My experience with an AF camera is that it cannot know what it is I want in focus--it simply searches for highest contrast within a given focus area (perhaps smaller than the RF patch but an area none the less).

 

Donald

[Einst_Stein]

The devil is always in the details on a scheme such as this. For example, what happens when you are at f8. How "in focus" is "in focus"? Further, how precise in area is the focus point? I often find that I focus on one aspect of what is within the patch of my RF. My experience with an AF camera is that it cannot know what it is I want in focus--it simply searches for highest contrast within a given focus area (perhaps smaller than the RF patch but an area none the less).

 

Donald

 

There is no such thing as the perfect solution in this world, particularly about M.

Everything your mentioned could be very valid.

I believe you have heard similar argument about auto exposure. Yes, the camera does not know which point to meSure the light, should it be center spot or average or whatever.

With the technology improvement, I learned to search the positive side, you can always find some, not just few, negatives about the new things, but what is important is to find the positive ones.

 

My proposal surely won't be the best solution, and it is likely to take several trials to get better, but the core value of the Leica philosophy is to let the user to concentrate on the photography and leave the technique behind. The core value of technology is to hide the technology while let people accomplish the essence of the goal.

 

Leica is perhaps the slowest in picking up the modern electronic computing technology, but it also appears as the most elegant one when it does it. All the nice new things in M9, M monochrome, and M240 are examples. The X and T is the extension go that. It deserve a good plause.

 

Now, I believe Leica is willing to applied any of these good thing to M if possible.

 

I would shout loudly, Go, Go, Leica, don't be afraid if not perfect in the first time.

[jaapv]

Indeed, it is the same about exposure; reason I use it rarely.

[Guest volker_m]

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the shutter will fire when the focus error is -2,-1 , 0, 1, 2 inches.

 

How does the camera know it is in focus, without iterating back and forth across the range?

And even more challenging: How does the camera know it is xx inches off the focus point?

[mjh]

Focus confirmation is something Leica had tried when they developed the M (Typ 240). It didn’t work as reliably to be useful and so this feature was scrapped. I don’t think this is something one could ever get right in an M context.

[Einst_Stein]

How does the camera know it is in focus, without iterating back and forth across the range?

And even more challenging: How does the camera know it is xx inches off the focus point?

 

Perhaps you should ask first how does it know it is in focus or not in focus.

 

A servo system, such as AF, works on some kind of error measurement and/or error prediction. This process will determine when the error reaches its minimum value and predicts how far is from that minimum value. The error can be calibrated, albeit with focal length and aperture dependency, to distance.

[Einst_Stein]

Focus confirmation is something Leica had tried when they developed the M (Typ 240). It didn’t work as reliably to be useful and so this feature was scrapped. I don’t think this is something one could ever get right in an M context.

 

I think we can use a little common sense.

 

1. Whatever a DSLR can do, M can do it too except that the legacy M lenses do not have motor-driven focusing.

 

2. DSLR AF system contains the focusing master component and focusing slave component. The focusing master component is usually in the camera body, which performs the measurement and prediction etc., and sends focusing control command to the focusing motor to drive the lens.

 

3. M camera can do everything the focusing master does except it does not have the motorized lens. The missing piece is the human's hand.

 

There is no reason M can't do a good job in focusing measurement and prediction except that it is a bit of learning curve for Leica.

[mjh]

Whatever a DSLR can do, M can do it too except that the legacy M lenses do not have motor-driven focusing.

‘Legacy M lenses’? There is just one kind of M lenses and these, from the oldest to the latest up to those still in development, are focused manually. This is by design. For one thing it is the main reason why these lenses are relatively small for their speed and Leica has no intention of changing that.

 

And by the way, why should an M do everything a DSLR could do? It’s not a DSLR and that’s the point. Of Leica’s three camera systems, two support automatic focusing, as do all of Leica’s compact cameras. Only the M system does not and that is one of its distinguishing features.

 

There is no reason M can't do a good job in focusing measurement and prediction except that it is a bit of learning curve for Leica.

As I had explained Leica had implemented such a feature and scrapped it because it turned out it wasn’t such a good idea after all. So yes, they have done their homework and they have learned their lesson.

[Einst_Stein]

No one said M has to evefythibg DSLR does. But M can if needed, except all existing M lenses do not have motor driven focusing. Tbere is no reason new M body cannot pick up the focusing asistant features.

 

Your early comment about M240 AF attemp and conclusion that M can not do reliable focusing asistant is ansolutely absurd.

 

 

‘Legacy M lenses’? There is just one kind of M lenses and these, from the oldest to the latest up to those still in development, are focused manually. This is by design. For one thing it is the main reason why these lenses are relatively small for their speed and Leica has no intention of changing that.

 

And by the way, why should an M do everything a DSLR could do? It’s not a DSLR and that’s the point. Of Leica’s three camera systems, two support automatic focusing, as do all of Leica’s compact cameras. Only the M system does not and that is one of its distinguishing features.

 

 

As I had explained Leica had implemented such a feature and scrapped it because it turned out it wasn’t such a good idea after all. So yes, they have done their homework and they have learned their lesson.

[jdlaing]

No one said M has to evefythibg DSLR does. But M can if needed, except all existing M lenses do not have motor driven focusing. Tbere is no reason new M body cannot pick up the focusing asistant features.

 

Your early comment about M240 AF attemp and conclusion that M can not do reliable focusing asistant is ansolutely absurd.

 

There is no communication whatsoever between the lens and body. The only contact are the frame lines for rangefinder focusing. It is what it is and thats why we like it. The M bodies don't require or need all that fancy stuff.

[jaapv]

No one said M has to evefythibg DSLR does. But M can if needed, except all existing M lenses do not have motor driven focusing. Tbere is no reason new M body cannot pick up the focusing asistant features.

 

Your early comment about M240 AF attemp and conclusion that M can not do reliable focusing asistant is ansolutely absurd.

 

Not that absurd. It would need a contrast reading off the sensor at the point of the RF patch, and some way to project that into the viewfinder, synchronising the optical and digital systems. Maybe if Leica ever introduces a hybrid viewfinder (which I sincerely hope not) that such a thing would become practical. It would probably be as popular as the Video function now...

[mjh]

Tbere is no reason new M body cannot pick up the focusing asistant features.

How would you go about implementing such a feature?