A true digital rangefinder?

Fabio Ruffet

Fabio
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So maybe a stupid question but given the advancement in digital focusing ie. focus peaking, auto focus etc, why can't there be a digital rangefinder type of focus?

Effectively you could have an EV with a square patch digitally super imposed to the image, and as you focus on an object, the square aligns

or even better this could be applied to a hybrid optical/EV (ie Xp1). So the image is via the optics but the rangefinder operates digitally

This would remove the cost of the optical rangefinder in a camera like the M9 but still keep the same user experience and couple with existing lenses

thoughts?
 
Probably possible but I doubt it would have widespread appeal. First, it seems like a rather odd superimposition of a mechanical necessity onto a digital device. Next, EVFs still have a long way to go. Finally (and perhaps most tellingly) you wouldn't be able to see the scene outside the viewfinder frames, so it wouldn't really be anything like the same user experience.

Cheers,

R.
 
It wouldn't be practical at all. There's no reason for a system like that unless its for people that just want the nostalgic feeling of using a rangefinder. In a sense, doing that would be a little bit backwards. Manufacturers could implement it as an option/feature in the future, but I don't think it'd ever take off as a primary way of focusing.
 
A possible compromise, which I think would not be very difficult at all, would be to have an indication of the focus outside the frame. For example, having to line up two lines to focus manually. Some Nikon dSLRs already indicate which way to turn the lens when focusing manually, and when you've achieved focus. What they don't do, though, is indicate how close or far to being in focus you are.
 
Ha, I suggested this in a thread here when the Fuji X100 was announced. Still think it's a great idea and we will likely see it in a Leica in the future when all other brands keep passin up on it. Any brand that adopts this might be THE future RF-like manufacturer in the future and even beat Leica at their own game, since production of that RF-like system would be cheaper.

The hybrid VF from the X100 would allow a view outside the frames while projecting an RF spot to line up with the view through an optical VF.
 
So maybe a stupid question but given the advancement in digital focusing ie. focus peaking, auto focus etc, why can't there be a digital rangefinder type of focus?

Effectively you could have an EV with a square patch digitally super imposed to the image, and as you focus on an object, the square aligns

or even better this could be applied to a hybrid optical/EV (ie Xp1). So the image is via the optics but the rangefinder operates digitally

This would remove the cost of the optical rangefinder in a camera like the M9 but still keep the same user experience and couple with existing lenses

thoughts?
I think you have missed the idea of rangefinder:
Leica rangefinder is a measuring tool that gives information where the optimum focus with a given lens is. You can choose pinpoint focus, that is the big and small window images are exactly superimposed, You can choose frontal focus: The small frame image is to the right or then small frame image is to the left. That way you can have the focus more to infinity. This has an effect on how the image shows. Not always you want the focus to be on the main part of the image. also you can decide how the area of focus distributes: You measure with the rangefinder the nearest and furthermost location what you want to have in focus. Place the lever halfway between and look at the depth of field scale where the aperture will be to have the image the way you want. It is as important as leica finder showing what comes to the frame/ image and what is left out.
 
In fact Leica, Nikon, Bushnell and probably a number of other companies make laser rangefinders for measuring distances (look up Lieca Rangemaster). I have wondered for some time if this technology could be used to replace the mechanical rangefinders in cameras, and if so what the advantages and disadvantages would be.
 
I think you have missed the idea of rangefinder:
Leica rangefinder is a measuring tool that gives information where the optimum focus with a given lens is. You can choose pinpoint focus, that is the big and small window images are exactly superimposed, You can choose frontal focus: The small frame image is to the right or then small frame image is to the left. That way you can have the focus more to infinity. This has an effect on how the image shows. Not always you want the focus to be on the main part of the image. It is as important as leica finder showing what comes to the frame/ image and what is left out.

Many Thanks for the kind explanation but I have a couple of Leicas and fuji and I understand this principle. My question is, why does this have to be done optically. Why can't the same principle be replicated digitally?

Take a look around in your own household right now and you will see things that were unthinkable 5 years ago are just built into simple everyday products. So the answer can't just be technical difficulty. Lack of demand versus investment would be a more plausible explanation though

But again, this could be done mostly or entirely via software as the camera already 'knows' what's in focus and what isn't (that was my original badly phrased point)
 
Many Thanks for the kind explanation but I have a couple of Leicas and fuji and I understand this principle. My question is, why does this have to be done optically. Why can't the same principle be replicated digitally?



But again, this could be done mostly or entirely via software as the camera already 'knows' what's in focus and what isn't (that was my original badly phrased point)
Of couse the camera "knows" but does it tell you what it wants. I have also several "autofocus" cameras, but I consider them to be "out of focus" cameras. The focus is somewhere else that I want it to be...
 
Of couse the camera "knows" but does it tell you what it wants. I have also several "autofocus" cameras, but I consider them to be "out of focus" cameras. The focus is somewhere else that I want it to be...

Obviously AF is technically viable and highly successful. Tens of thousands of full-time professionals get paid for images everyday from AF cameras. So do millions of amateurs who enjoy and display well-focused photographs.

Some how all these photographers get AF to focus exactly where they want or need it to be. If you really wanted or needed to work with AF, I am confident you would also achieve success. At the same time I understand the satisfaction experienced by manually focusing an analog camera system.

There is no need for you to work with AF... so don't do it. But realize it's not credible to suggest AF can not perform as well as MF.
 
Obviously AF is technically viable and highly successful. Tens of thousands of full-time professionals get paid for images everyday from AF cameras. So do millions of amateurs who enjoy and display well-focused photographs.

Some how all these photographers get AF to focus exactly where they want or need it to be. If you really wanted or needed to work with AF, I am confident you would also achieve success. At the same time I understand the satisfaction experienced by manually focusing an analog camera system.

There is no need for you to work with AF... so don't do it. But realize it's not credible to suggest AF can not perform as well as MF.
Alas I cannot quote chapter and verse but I have seen more than one study suggesting that for the ultimate in precision, through not necessarily speed, manual focus works better. Personally I find it faster and more reliable to focus my Leicas than to rely on autofocus, but as you suggest, that's probably just habituation.

Chers,

R.
 
All focusing systems have errors. An optical rangefinder is a problem because you usually don't know that it is out of adjustment until after the fact and you hold a bunch of fuzzy photos in your hands.

Autofocus, while certainly not foolproof, can usually focus faster and more accurately than most people...especially those of us with aging eyes. The 1DMkIV I shoot sports with can keep an erratically running football player on a dimly lit high school football field perfectly in focus while shooting 10 fps.
 
All focusing systems have errors. An optical rangefinder is a problem because you usually don't know that it is out of adjustment until after the fact and you hold a bunch of fuzzy photos in your hands.

Autofocus, while certainly not foolproof, can usually focus faster and more accurately than most people...especially those of us with aging eyes. The 1DMkIV I shoot sports with can keep an erratically running football player on a dimly lit high school football field perfectly in focus while shooting 10 fps.
You are of course right: I was thinking about reflex focusing on a well-adjusted SLR, not coupled rangefinders, where you need (a) really good adjustment (b) no focus shift and as you say (c) faith that it's working.

Cheers,

R.
 
Still, with the increase of EVF quality it should be no biggie to create a rangefinder-like focus system that is mostly digital-based.

First of all a bit of understanding the RF experience: when focusing a Leica, it's in fact two different methods you are using at the same time. One is the superimposed images, but the other comes from the sharp-edged RF patch. Line up the objects inside and outside the patch and you're in focus. This aspect is what is needed for a digital RF mechanism.

The X100 projects digital data in the optical viewfinder, right? So, why not take a square bit of the sensor image and project it in the middle of the optical viewfinder? It does not have to be superimposed, just the sensor image! When the camera is in focus, that little square will be in focus, and it will line up with the optical image.

Along with that it'll be quite easy to have framelines in the viewfinder, like any rangefinder camera.

I really cannot understand why no manufacturer is getting into this. Like I said, I presume that it is a much cheaper to produce RF system that will sufficiently mimic the Leica RF.
 
Alas I cannot quote chapter and verse but I have seen more than one study suggesting that for the ultimate in precision, through not necessarily speed, manual focus works better. Personally I find it faster and more reliable to focus my Leicas than to rely on autofocus, but as you suggest, that's probably just habituation.

Chers,

R.
very few photographers,not counting view camera shooters, are using the depth of field scale propely. My father, an amateur photographer shooting with leica already in the 30`s taught me the virtues of it when I got my first M2 and 35mm summicron. The depth of field scale was an invention by a finn VILHO SETÄLÄ, a friend if my father. It was adopted by leitz when his leica was sent to factory for repair and they copied it from his lenses. That was the time when rangefinder was the extra gizmo on top of the Leica I. It still has the same function, for those that are smart enough to use it!
 
Still, with the increase of EVF quality it should be no biggie to create a rangefinder-like focus system that is mostly digital-based.

First of all a bit of understanding the RF experience: when focusing a Leica, it's in fact two different methods you are using at the same time. One is the superimposed images, but the other comes from the sharp-edged RF patch. Line up the objects inside and outside the patch and you're in focus. This aspect is what is needed for a digital RF mechanism.

The X100 projects digital data in the optical viewfinder, right? So, why not take a square bit of the sensor image and project it in the middle of the optical viewfinder? It does not have to be superimposed, just the sensor image! When the camera is in focus, that little square will be in focus, and it will line up with the optical image.

Along with that it'll be quite easy to have framelines in the viewfinder, like any rangefinder camera.

I really cannot understand why no manufacturer is getting into this. Like I said, I presume that it is a much cheaper to produce RF system that will sufficiently mimic the Leica RF.
Just wait and see, the "M" will be quite nice to use... No autofocus but red lines on the image where the pinpoint focus will be, no room for focusing errors...
 
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