Shade Posted October 3, 2011 Share #21 Posted October 3, 2011 Advertisement (gone after registration) Blimey. Imagine how slow auto focus would be on Leica lenses... It take brute force to focus my 90mm Summicron by hand. You'd need a powerful motor to focus that. The battery would take some serious punishment too. I agree with you, I don't think it's workable - Leica would need to design from ground up to create AF-M lenses. Link to post Share on other sites More sharing options...
Advertisement Posted October 3, 2011 Posted October 3, 2011 Hi Shade, Take a look here Autofocusing an M lens?. I'm sure you'll find what you were looking for!
adan Posted October 3, 2011 Share #22 Posted October 3, 2011 Just to make sure - everyone DOES realize we are talking about a (hypothetical) Ricoh product, not something Leica would offer themselves? Link to post Share on other sites More sharing options...
AlanG Posted October 3, 2011 Share #23 Posted October 3, 2011 Blimey. Imagine how slow auto focus would be on Leica lenses... It take brute force to focus my 90mm Summicron by hand. You'd need a powerful motor to focus that. The battery would take some serious punishment too. I don't think any designer would consider such an approach. But once cameras have phase detect elements on the sensor and don't require a shutter, focusing via moving the sensor will be an option... certainly possible for smaller sensor cameras that have interchangeable lenses. This would eliminate or minimize the need for focusing mounts in lenses. Thus saving complexity, bulk and weight. If lenses require some elements to be moved independently, that can be accomplished with a motor, or motors, in the lens and an electronic interface. I'd think this would give even more options for using floating element designs. And this would be simpler to implement than designing precise all mechanical floating element focusing systems. It would make it much easier to weather seal a camera too. If the sensor can move 25mm this would cover a pretty good focusing range for up to portrait length lenses that fit M4/3rd cameras or smaller sensors. Longer lenses would probably require some kind of additional focusing system. Note - I am thinking of hypothetical future cameras here and not necessarily anything specific for Leica lenses. But I don't see why a Leica lens could not be used on such a system even if the AF only worked in a relatively narrow range with some lenses. Link to post Share on other sites More sharing options...
eleskin Posted October 3, 2011 Share #24 Posted October 3, 2011 I always felt the Contax AX was a stroke of genius. Some have reported the system had problems while others loved it. Even if there were some technological glitches back then, surely with the incredible technology of today you could build a much better and more compact version of the Contax AX system to acmomidate Leica M lenses (R lenses, any lens!!!) with a moving sensor. I really would not care if the camera were a little thicker and larger than the current M9 in that a camera like this would be more like a working tool more than a thing of beauty. I would not even care if you had to pre focus a bit to get it within range to autofocus correctly. I would love that with my Noctilux at f1.0! Link to post Share on other sites More sharing options...
bill Posted October 3, 2011 Share #25 Posted October 3, 2011 The AX relied upon ceramic rails from the parent, Kyocera. It was a kluge, that suffered from a reputation for fragility and unreliability. I was a big Contax user at the time, with a brace of RXs and thought it a turn in the wrong direction. If I want AF I'll use an AF camera system with dedicated lenses designed from the ground up. And the thought of a future M being fatter still is just ludicrous. Regards, Bill Link to post Share on other sites More sharing options...
AlanG Posted October 3, 2011 Share #26 Posted October 3, 2011 I always felt the Contax AX was a stroke of genius. Some have reported the system had problems while others loved it. Even if there were some technological glitches back then, surely with the incredible technology of today you could build a much better and more compact version of the Contax AX system to acmomidate Leica M lenses (R lenses, any lens!!!) with a moving sensor. I really would not care if the camera were a little thicker and larger than the current M9 in that a camera like this would be more like a working tool more than a thing of beauty. I would not even care if you had to pre focus a bit to get it within range to autofocus correctly. I would love that with my Noctilux at f1.0! This was a problem with film SLRs because the entire mirror box, prism, shutter, film plane, etc. had to be moved inside the exterior camera "shell." For a digital M this would still require the shutter to move back and forth with the sensor and would enlarge the camera significantly. I don't see this being practical. But if you consider that future cameras won't require a mechanical shutter, it may become a more viable solution to move the sensor. While such a camera could take M lenses, it won't likely have much in common with an M. I guess an optical viewfinder could be retained and the rangefinder could be linked to the AF system. But the camera would basically be working in "live view" mode all of the time. Link to post Share on other sites More sharing options...
Shade Posted October 4, 2011 Share #27 Posted October 4, 2011 Advertisement (gone after registration) If the sensor can move 25mm this would cover a pretty good focusing range for up to portrait length lenses that fit M4/3rd cameras or smaller sensors. Longer lenses would probably require some kind of additional focusing system. Note - I am thinking of hypothetical future cameras here and not necessarily anything specific for Leica lenses. But I don't see why a Leica lens could not be used on such a system even if the AF only worked in a relatively narrow range with some lenses. Hypothetically - wouldn't that make the camera thicker though? 25mm is quite thick for a movement space, then you would have to add extra thickness for the casing, the machinary and whatnot around the sensor. Link to post Share on other sites More sharing options...
AlanG Posted October 4, 2011 Share #28 Posted October 4, 2011 Hypothetically - wouldn't that make the camera thicker though? 25mm is quite thick for a movement space, then you would have to add extra thickness for the casing, the machinary and whatnot around the sensor. You are looking at this the wrong way. It would not make the camera thicker if the lenses were set at their closest focusing distance. The sensor would just move forward to reach infinity - assuming the case is more than 25mm thick or so. The mechanism to move the sensor could be pretty small, fast, and efficient - consider how much more mass is moved in many AF lenses. My bet is that before long an entire new small format system will appear that uses all of this technology - no shutter, no focusing mechanism in the lenses, EVF, on sensor phase detection AF. It simplifies everything dramatically. The new Nikon N1 has most of this but not the moving sensor. Some lens designs will still require motors to move various elements or groups independently. Link to post Share on other sites More sharing options...
mjh Posted October 4, 2011 Share #29 Posted October 4, 2011 It would not make the camera thicker if the lenses were set at their closest focusing distance. Huh? Of course it would. With a focusing lens, the body is as thick as it needs to be for infinity focusing; the lens tube is extended to focus on closer subjects. If you design the body so the lens is focused to the closest focusing distance and move the sensor to focus on subjects farther away, the body needs to be correspondingly thicker. (The lens wouldn’t need to extend, though.) Link to post Share on other sites More sharing options...
bill Posted October 4, 2011 Share #30 Posted October 4, 2011 Just remind me again why anyone would think this is a good idea...? Regards, Bill Link to post Share on other sites More sharing options...
pop Posted October 4, 2011 Share #31 Posted October 4, 2011 Just remind me again why anyone would think this is a good idea...? Regards, Bill It's not. It's an abomination. Just like using a board with a lot of little buttons instead of a quill for writing and lots of teeny little lamps behind a pane of glass in place of a parchment for showing the writing. Link to post Share on other sites More sharing options...
AlanG Posted October 4, 2011 Share #32 Posted October 4, 2011 Huh? Of course it would. With a focusing lens, the body is as thick as it needs to be for infinity focusing; the lens tube is extended to focus on closer subjects. If you design the body so the lens is focused to the closest focusing distance and move the sensor to focus on subjects farther away, the body needs to be correspondingly thicker. (The lens wouldn’t need to extend, though.) The body would not necessarily have to be thicker if the lens is extended to a closer focusing distance. But of course the lenses may have to be slightly longer if they are made without any kind of focusing mount. (This could be collapsible to save space on longer lenses.) But consider that short to normal focal length lenses, even on full frame cameras, do not extend much when focusing to 1 meter or so. AF systems especially could benefit by many lenses being smaller and lighter by eliminating the AF motors and focusing mechanism entirely. The sensor would start at the back of the camera where it currently is. This would give close focusing. Then it only has to move forward 1 inch (25mm) at most to achieve infinity focus. That is within the thickness parameters of many cameras today. 25mm of movement would allow very close focusing with a 50mm lens so this will be adequate for quite a range of lenses especially on smaller sensor cameras. This may be more than is typically needed. In any case, future camera designs could decide how far to move the sensor vs. having some focusing mechanism in the lens. Nikon and Contax RF cameras worked this way by having a helical for most lenses in the body and longer lenses had their own focusing helicals. The body helical didn't come close to extending 25mm. Link to post Share on other sites More sharing options...
AlanG Posted October 4, 2011 Share #33 Posted October 4, 2011 Just remind me again why anyone would think this is a good idea...? Regards, Bill Cameras and lenses could be smaller, lighter, faster in operation, simpler and easier to make, need less power, easier to weather seal, silent, more versatile, have faster sync speed, probably less expensive, etc. Link to post Share on other sites More sharing options...
bill Posted October 4, 2011 Share #34 Posted October 4, 2011 Correct me if I'm wrong but this thread is about autofocussing existing M lenses. The desperate need for that is what I don't get. Why take something designed to perform a specific function exceptionally well and make it do something else worse than existing tools designed to do that? Regards, Bill Link to post Share on other sites More sharing options...
AlanG Posted October 4, 2011 Share #35 Posted October 4, 2011 Correct me if I'm wrong but this thread is about autofocussing existing M lenses. The desperate need for that is what I don't get. Why take something designed to perform a specific function exceptionally well and make it do something else worse than existing tools designed to do that? Regards, Bill I have no idea if there is a desperate need by any M users for AF. But should Leica or anyone else introduce a camera that has AF via a moving sensor, this could be a way to have AF using M lenses. Whether you care for it or not, this is just a discussion of possibilities. If nobody spent time thinking of new possibilities, we'd still be living in caves. Link to post Share on other sites More sharing options...
pop Posted October 5, 2011 Share #36 Posted October 5, 2011 ... thread is about autofocussing existing M lenses. The desperate need for that is what I don't get. Why take something designed to perform a specific function exceptionally well and make it do something else worse than existing tools designed to do that? The M lenses are designed exceptionally well to take pictures of what's in front of them. They are designed moderately well to work with the range finder of the M camera body. The need to adjust lens, body or both in order to obtain a reasonable accuracy is well documented and rather often observed. While the purely optical qualities are very hard to achieve, varying the distance between a group of lenses and a plate of light sensitive material is not nearly as demanding, even when the constraints on the geometry are taken under consideration. You move one of those parts, or two, to and fro. Some of us have sunk as much money as they can reasonably afford (or even more) into those lenses because of their outstanding quality, i.e. because of the way they render images. I, for one, would find it very desirable if those lenses could be used with other bodies which support other shooting circumstances better than the M type body. There used to be a time when Leica served that need after a fashion, with the Visoflex. It does not seem reasonable to me that I should have to buy another set of lenses just in order to extend the available modes of operating my cameras. I'm no Croesus and no athlete. While the opto-mechanical range finder of the M system is a very elegant concept for certain modes of operations, it is not equally well adapted to all situations. I have been using cameras with auto focus (as has everyone here) and can attest that they make reasonably well focused images under circumstances where I can not use the opto-mechanical RF. Link to post Share on other sites More sharing options...
andybarton Posted October 5, 2011 Share #37 Posted October 5, 2011 If you have a camera body that moves a sensor in order to focus, you are not autofocusing an M lens, you are autofocusing the body. Link to post Share on other sites More sharing options...
pop Posted October 5, 2011 Share #38 Posted October 5, 2011 If you have a camera body that moves a sensor in order to focus, you are not autofocusing an M lens, you are autofocusing the body. The question is moot since focusing means adjusting the distance between lens and body. Link to post Share on other sites More sharing options...
bill Posted October 5, 2011 Share #39 Posted October 5, 2011 I have absolutely nothing against AF; people tend to forget that I was the first to use a digital AF camera on the One Challenge years ago This is not about "progress", its about commonsense. What I am taking issue with is the flawed "logic" of fitting an outboard motor to a coxless fours boat; its a compromise that may be possible but adds no value and makes no sense "I wouldn't start from here if I were you" as my Grandfather used to say when asked for directions. Regards, Bill Link to post Share on other sites More sharing options...
AlanG Posted October 5, 2011 Share #40 Posted October 5, 2011 What I am taking issue with is the flawed "logic" of fitting an outboard motor to a coxless fours boat; its a compromise that may be possible but adds no value and makes no sense "I wouldn't start from here if I were you" as my Grandfather used to say when asked for directions. Regards, Bill You could also say that if the M didn't already exist, there is no logical reason to think that Leica would have designed the M9 to be the way it is either. You can't get much simpler than a manual lens. View cameras work by moving the back to focus. And if the sensor moves for focus that would be about best way to do AF with a non-floating glass lens, I figure. Link to post Share on other sites More sharing options...
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