M9, last of the line?

[haroldp]

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That the red edge is caused by lack of telecentricity seems to be a reasonable assumpttion, as it is a WA problem. I'm sure the development department at Leica knows more than they are telling

 

Jaap:

 

You have hit on an important point.

 

The WATE appears free of this problem even at 16mm, but it is telecentric, (and a real zoom lens).

 

Perhaps a wider mount would permit a faster WATE ?.

 

Regards .... Harold

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[jaapv]

In theory, yes, but the diameter of the front lens is a consideration as well.

[jonoslack]

It could be a non-symmetrical filter, but it seems doubtful, as there have been other cameras with the same problem. Another thing that points at telecentricity is that it does not happen with my 16 mm Fisheye - but that is an R lens with a long register. It may not be the cause, you are right there - but it seems to be the cure.

 

Hi Jaap

I spent many many happy ours filling in spreadsheets full of data for Kodak, trying to solve the 'Italian Flag' issue with the Kodak SLR/n - nobody ever got to the bottom of it (as far as I know), and the symptoms weren't quite the same, but similar, but they were not caused by telecentricity (some very wide lenses performed well, whereas the Nikon 70-200 f2.8 was the worst culprit).

 

To say that lack of telecentricity is the cause of the red edge is a bit like saying that cars are the cause of car crashes - sure, if nobody drove cars there wouldn't be any car crashes, and if everybody used telecentric lenses there wouldn't be red edges. A better understanding of WHY non-telecentric lenses cause red edges on the M9 might easily provide a cure within the camera (or at least for the M10), then we could all go on using the 21 elmarit, 25 biogon and 15 CV lenses of this world. Surely a better solution than a larger lens mount, which, if you use an adaptor, is only going to bring those old faithful lenses back to the same position vis a vis the sensor, and presumably to the same problem with red edges.

[ohnri]

Of course, electronic focus confirmation (see my earlier post) could use any part of the cmos sensor. This way, one could choose any location in the image to be in perfect focus easily, thus somewhat mitigating the need to focus and recompose.

 

It would also be helpful for lenses that display significant curvature of field.

 

And the option of using the RF patch would always be available, therefore adding functionality without losing the essential feel of the RF camera.

 

Best,

 

Bill

[rosuna]

A CMOS sensor cannot provide focus confirmation for a future M camera.

 

EVIL cameras focus using the sensor as a contrast checker device, but the AF mechanism is moving the focus plane back and forward comparing the resulting contrast in the AF selected area (or point). It is some kind of optimizing algorithm which looks for a fast convergence to the optimal point.

 

M cameras are manual focus cameras, and you have the focus control. So the sensor doesn't get information for the calculations. In theory, you would have to do the (many) back and forward operations required by the processor for the calculations, moving the focus ring. It is impossible.

 

Focus confirmation is possible with reflex cameras because the AF "rangefinder" system is measuring the exact distance for a perfect focus. You may install one of those AF systems in a manual focus reflex camera as well. The camera knows that distance and let you know when you focus position is correct. Compact cameras also have focus confirmation in MF mode, but I guess they are performing AF movements on the lens in parallel while you change the position of the wheel or ring.

 

Focus confirmation in a M camera would need a different solution.

[perb]

A CMOS sensor cannot provide focus confirmation for a future M camera.

 

EVIL cameras focus using the sensor as a contrast checker device, but the AF mechanism is moving the focus plane back and forward comparing the resulting contrast in the AF selected area (or point). It is some kind of optimizing algorithm which looks for a fast convergence to the optimal point.

 

M cameras are manual focus cameras, and you have the focus control. So the sensor doesn't get information for the calculations. In theory, you would have to do the (many) back and forward operations required by the processor for the calculations, moving the focus ring. It is impossible.

 

Focus confirmation is possible with reflex cameras because the AF "rangefinder" system is measuring the exact distance for a perfect focus. You may install one of those AF systems in a manual focus reflex camera as well. The camera knows that distance and let you know when you focus position is correct. Compact cameras also have focus confirmation in MF mode, but I guess they are performing AF movements on the lens in parallel while you change the position of the wheel or ring.

 

Focus confirmation in a M camera would need a different solution.

 

You describe a closed loop AF solution, but what if we open the loop and let the photographer be the "man in the loop"?

 

Imagine the viewfinder mostly like it is today, with the rangefinder patch in place and fully functional. We only aim to enhance the photographer's ability to determine where pefect focus occurs. What if we somehow could present the contrast/focus metric in the viewfinder, so that we get roughly to the required focus in the usual manner by looking at the rangefinder patch, and then for finetuning we use the the metric, and of course still keep an eye on the rangefinder patch for dual confirmation? We could have a small but easy to read bar with increasing height as the metric increases, a bit like a vertical higher resolution battery indicator, integrated in the display unit.

 

Of course this assumes that the contrast/focus metric will vary with small adjustments as to be useful.

 

Regards

Per

[adan]

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Focus confirmation is possible with reflex cameras because the AF "rangefinder" system is measuring the exact distance for a perfect focus.

 

Hmm - are you saying that if I mount an unchipped manual focus lens on a Nikon D700 - or a Contax RTS lens on a Contax RX body (which has focus confirmation but not AF), that something in the camera knows not only that the image is sharp, but also that the lens is set to 1.3 or 2.5 meters (I.E. the "exact distance")?

 

I do not think that is correct. SLR AF systems DO measure relative focus, so they can tell you which direction to turn the lens to get to sharp - i.e closer or farther. But not the actual subject distance (Chipped lenses that track the position of the lens elements add this capability, however - e.g. "AF-D" Nikkors)

 

By contrast, the Contax G cameras can, in fact, give one a fairly precise readout of subject distance even without a lens mounted, since they use an active IR-beam triangulation system. Point one at a wall, and it can tell you "1.25 meters" or "3.7 meters" on the little LCD on the left top cover.

 

I think you are correct, though, that a contrast-detect system off of an image sensor cannot tell you which way to turn the lens to improve contrast (= focus).

[swamiji]

I don't see a M10 any time soon, could be years, I don't even think we'll see an M9.2 ever. What I do see is an M9 Ala cart, where you can choose your options.

 

I also see a R replacement in the FF EVIL. Either using an R adapter, or native R mount. It will be the relief that Leica has been promising to the R users. Also it will have it's own set of lenses.

 

So there lineup will be:

 

Compacts

EVIL

M

S

[Xmas]

Indeed they are, but I doubt that Leica are losing much revenue to lenses that didn't sell in large numbers and are now discontinued <grin>

 

Yes but it did not help Leica when they were being marketed.

 

Noel

[jonoslack]

A CMOS sensor cannot provide focus confirmation for a future M camera.

 

EVIL cameras focus using the sensor as a contrast checker device, but the AF mechanism is moving the focus plane back and forward comparing the resulting contrast in the AF selected area (or point). It is some kind of optimizing algorithm which looks for a fast convergence to the optimal point.

 

M cameras are manual focus cameras, and you have the focus control. So the sensor doesn't get information for the calculations. In theory, you would have to do the (many) back and forward operations required by the processor for the calculations, moving the focus ring. It is impossible.

 

Focus confirmation is possible with reflex cameras because the AF "rangefinder" system is measuring the exact distance for a perfect focus. You may install one of those AF systems in a manual focus reflex camera as well. The camera knows that distance and let you know when you focus position is correct. Compact cameras also have focus confirmation in MF mode, but I guess they are performing AF movements on the lens in parallel while you change the position of the wheel or ring.

 

Focus confirmation in a M camera would need a different solution.

 

Interesting points.

However - some experience of using M lenses on an Olympus pen has shown that focus is very easy to achieve and recognise, are you saying that although it's easy to see when the lens is in focus on the LCD there is no way for the camera to recognise and acknowledge that?

[markgay]

Well, it's good to see that the idea of a design 'beyond the M' at least gets discussed without flamethrowers

 

Before we saw that Leica could design a full-frame digital M I raised the same issue here http://www.l-camera-forum.com/leica-forum/leica-m8-forum/47665-would-you-give-leica-free-hand.html and I'd say the split was 50:50.

 

I fall into the go-with-technology camp, caring first and foremost for the images I can get with a small rangefinder camera.

 

However many traditionalists also had strong arguments against a radical redesign, roughly in order of popularity:

 

Keeping backward-compatibility with M lenses

Keeping the optical rangefinder

Retaining the size and shape

 

Regards,

Mark

[rosuna]

Hmm - are you saying that if I mount an unchipped manual focus lens on a Nikon D700 - or a Contax RTS lens on a Contax RX body (which has focus confirmation but not AF), that something in the camera knows not only that the image is sharp, but also that the lens is set to 1.3 or 2.5 meters (I.E. the "exact distance")?

 

No, of course not. The camera is able to confirm the focus because the camera compares, knowing where are you focusing and where the focus should be, so some kind of electronic coupling between the lens and the camera is needed.

[rosuna]

Interesting points.

However - some experience of using M lenses on an Olympus pen has shown that focus is very easy to achieve and recognise, are you saying that although it's easy to see when the lens is in focus on the LCD there is no way for the camera to recognise and acknowledge that?

 

Well, no. When you use a M lens on a Pen camera you apply some kind of back and forward, sharpness based, focusing method, but using your eyes for evaluation. You control the focus ring, and you evaluate the result (on a LCD screen). The camera may do the same, on AF systems. What is impossible is to evaluate without controlling focus. You may discern if a focus position is sharper than other one, but without focus control you cannot say what is the sharpest position.

[jaapv]

 

Keeping backward-compatibility with M lenses

Keeping the optical rangefinder

Retaining the size and shape

 

Regards,

Mark

Those three are certainly not in conflict with a lens mount change, the only non-compatability being that the new mount lenses could not be used on older cameras, but then, M-mount lenses don't fit LTM cameras.

[ohnri]

some kind of electronic coupling between the lens and the camera is needed.

 

Hah! Not at all. Just imagine a row of small LED's along the bottom of the viewfinder. As the image becomes sharper more LED's illuminate. As you focus the MF lens more and more of the LED's would illuminate until you pass the point of maximum sharpness and then fewer and fewer would be lit up.

 

It would be very easy to find the precise point of maximum sharpness.

 

The LED's would be easily visible in your peripheral vision, no need to stare at them.

 

Remember the old stereo tuners where you would adjust the dial until you got maximum signal strength? Many of them used a similar interface.

 

Now, your 135mm lens will suddenly be fully useful even at max aperture.

 

Also, if there is a rudimentary electronic connection on the hotshoe you could put a small but smart finder on there that has it's own LED's incorporated for focus.

 

That would let you use Leica's brand new 200mm Summicron for the M series with manual focusing. Imagine the possibilities.

 

As far as the RF goes, it would be possible to develop a focus by wire system to replace the fully mechanical linkage.

 

Focus the lens which then moves the camera lever which signals a computer to cause a micro-motor to move the reflex mirror.

 

Now adjusting the RF for each lens and for different apertures for lenses with focus shift is simplicity itself.

 

Together, these ideas would work with every M lens and would be an adjunct to the RF system, not a replacement.

 

It would also allow the use of exciting new lenses like a 200mm, for example, which have previously been nearly excluded from RF use.

 

Now how much would you pay?

 

Best,

 

Bill

[stunsworth]

Bill, you've explained how you'd expect the camera./user interface to work. How would the actual AF focussing mechanism work - considering it would have to work well for f1 and f1.4 lenses?

[ohnri]

Bill, you've explained how you'd expect the camera./user interface to work. How would the actual AF focussing mechanism work - considering it would have to work well for f1 and f1.4 lenses?

 

You would need a CMOS sensor which can send data to a built in processor in real time. Then the processor would use a contrast detection method to determine sharpness at a spot that you determine. Probably that spot would be dead center but there is no reason it has to be. So focusing at a user selected location would now be possible if desired.

 

You would still focus the lens manually just as always. This way, all current M lenses are fully compatible. This is not a true autofocus, just manual focus with advice (but only when you want it).

 

This way you could either use the RF patch like we love doing now or you could use the LED's and let the camera help you determine the best focus point.

 

I guess that the RF patch would be used the vast majority of the time but in some conditions or with some lenses letting the camera advise you would be very useful.

 

Does that answer your question?

 

Best,

 

Bill

[lct]

....As far as the RF goes, it would be possible to develop a focus by wire system to replace the fully mechanical linkage.

Focus the lens which then moves the camera lever which signals a computer to cause a micro-motor to move the reflex mirror.

Now adjusting the RF for each lens and for different apertures for lenses with focus shift is simplicity itself.

Together, these ideas would work with every M lens and would be an adjunct to the RF system, not a replacement...

Interesting indeed. Any source to support this idea?

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Hallo,

Look here: Leica M

[luigi bertolotti]

Bill's explanations detail what I'd have in my mind... keep the future "M" as manual focus cameras, but with the legacy mechanical rangefinder simply thrown away: but the underlying technology must be REALLY ready to everything RF users do pretend... I mean, today the M's RFdoes allows to focus even in very dark situations.. some little detail of low luminosity, positioned where we want to focus, is sufficient to collimate the RF, and this even if (for some odd reason) we keep the diaphragm relatively closed... at 5,6 or so... all of this I think that with today technology is difficult to accomplish (but am not sure... never used AF cameras); moreover, the prospected Electronic VF on the accessory shoe, for long focals, is what is nearest to the concept of "new Visoflex" dreamed of by someone... it could be made, for instance, with 2 or 3 frames like 200-280-400 or 180-280 (depending on the lenses they would make... ).

Keeping the "legacy" RF TOGETHER WITH this possible new electronic confirmation system could be a nice dream... but I think , impossible to be accomplished, for reasons of space, if the form factor must be, wishfully, not too different from the current one.

[rosuna]

By contrast, the Contax G cameras can, in fact, give one a fairly precise readout of subject distance even without a lens mounted, since they use an active IR-beam triangulation system. Point one at a wall, and it can tell you "1.25 meters" or "3.7 meters" on the little LCD on the left top cover.

 

That is a possibility, and Leica knows something about it:

 

Leica Camera AG - Rangemaster

 

.