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Would an electronic rangefinder-lens coupling be relevant?

ypamine

New member
Having had an M9, but living in a country with no access to Leica services, I got more and more uncomfortable with the rangefinder calibration issue as the number of my lenses grew. I finally sold the M9 and have been using mirrorless cameras since.

With growing sensor resolution, the mechanical rangefinder-lens coupling is becoming a serious limiting factor.

Now, I was wondering if this could not be solved by replacing this mechanical by an electronic coupling. The position of the rangefinder roller, moved by the rangefinder helix of the lens as the focusing ring is turned, would be electronically measured. This measured position would then trigger the adjustment of the position of the rangefinder patch, for example using a servo or a digitally produced patch in an arrangement similar to the one used in the Fuji X-Pro1.

The obvious advantage of this is that no mechanical adjustment or calibration is required. Both RF roller and RF patch would never need to be adjusted after initial build of the camera. All adjustments and calibration could be done via software using a calibration profile for every camera-lens couple. This calibration could even be done by the enduser with the help of an EVF and a software supported procedure.

So one would set a calibration profile for every lens he wants to use on his camera, and the camera would upload the corresponding profile every time the lens is mounted. For lenses with strong focus shift, the owner of the camera could also choose at what aperture the calibration is done, depending on his preferences.

If this is possible, the list of improvements would be long, among them:
- software calibration allows to perfectly calibrate a camera with an unlimited number of lenses, which is very hard to do with a mechanical coupling
- in the field calibration is possible, with no risk of damage
- as the RF roller is not adjustable, the calibration will not be lost du to excessive vibration or mechanical shock
- focus shift can be taken into account
- etc.

Again, if this is possible, one would have the pleasure of using rangefinder focussing without the hassle of maintaining mechanical calibration.

If this has already been suggested or discussed elsewhere, don’t bother, but if not, I would be happy to have your opinion about the idea.
 

Godfrey

Well-known member
Yes it is possible, and feasible too. But. It might be even more expensive to manufacture than a mechanically coupled rangefinder, and more difficult to repair.

G
 
Arca Swiss has pretty much done this and I went through the process last year. They have a super fine helical for focusing (5 full turns - more accurate than roller in Leica) and designed the e-module cloud that can couple with the helical mount and sense the position and derive focus point or range. I had to send my mount in to get calibrated based on specific lenses models that I own, they went through some calibration and wrote it to an SD card which is inserted into the e-module. It can tell you the distance of focus range base on aperture which is quite handy. The part that I think would be challenging is size of the mechanism and also accuracy to accommodate a range of lenses. The helical used to be dialed by hand according to a chart hyper accurately but after calibration to work with the e-moduel accurate focus only works for mid to far range and is not very accurate in the close range especially when the focal length goes up. My guess is they have to find a median to work with all the lenses since the variables are so wide. I also think the focusing is non-linear which makes it hard to satisfy every lens due to the compound range. I agree with Godfrey that cost will be going up a lot and draws more power for it, too.

An EVF is pretty much the easiest solution without modifying the M shape or layout so in a way that is the best solution. If you need critical focus for photography you can probably put up with zoomed in live view anyhow. Other than that, the simple and nimble rangefinder is hard to beat.

I have a feeling Leica has looked into the rangefinder improvements over the years and decided not to tamper with it. The fact it is small and does not require power is its strength. It works pretty well and yes calibration is of concern depending on access or usage, I did adjust my M8 before and hence the P versions with a screw is way easier but I haven't had to do it for the M9-P. You may consider getting the tool yourself from ebay.
 

Godfrey

Well-known member
...
An EVF is pretty much the easiest solution without modifying the M shape or layout so in a way that is the best solution. If you need critical focus for photography you can probably put up with zoomed in live view anyhow. Other than that, the simple and nimble rangefinder is hard to beat.

I have a feeling Leica has looked into the rangefinder improvements over the years and decided not to tamper with it. The fact it is small and does not require power is its strength. It works pretty well and yes calibration is of concern depending on access or usage, I did adjust my M8 before and hence the P versions with a screw is way easier but I haven't had to do it for the M9-P. You may consider getting the tool yourself from ebay.
I'm sure they have. And thus we have the T system: smaller, lighter, no less well made, new lenses designed for and integrated with it that seem to be splendid to a one, and a very high-quality EVF. I think this is the future for Leica in new technology, and they'll keep developing and refining the digital M for the RF lenses and users.

To my mind, there doesn't have to be just one solution or product line. :)

G
 

jonoslack

Active member
I have a feeling Leica has looked into the rangefinder improvements over the years and decided not to tamper with it.
Except they really have changed the rangefinder in the M240 - tolerances have been improved considerably, and most users recognise and approve the changes. It may still need to be adjusted, but with the M240 it's done by machine rather than by hand, which makes it much more precise.

The big difference seems to be that one no longer needs to have one's lenses and camera calibrated together.
 

Paratom

Well-known member
To me this sounds way to complicated to become truth.
Plus there stil might be tolerances in the interface between the RF roller and the electronic parts.
I believe there is a much higher chance Leica would develop a M body with an integrated high resolution electronic viewfinder with some focus aid (maybe not focus peaking but something comparable to the rangefinder) but no optical finder.
IMO this viewfinder would have to be of very high resolution and DR to be accepted by M users.
If I see the difference between the VF2 and the current visoflex EVF it is obvious. If the next generation EVF appears even better by the same margin...this could be it. I say this as someone who has prefered optical viewfinders all the time but now with the Visoflex and the A7II and EM1 I think the difference is not that pronounced any more. So next generation we might be there.
Over the years I came to the conclusion that the M system works best for
lenses 50mm and smaller
f2.0 and slower
Thats why I dont use/own the superfast M lenses any more. FOr super shallow DOF SLRs and AF cams work better IMO. Just to many factoes which can lead to focus inaccuracy of rangefinder: mechanical parts lens, mechanical parts camera, coupling, focus shift, optical parts camera, optical parts lens
pretty impressive how good it works anyways
 

aDam007

New member
you could keep the same analog design and the only thing you change out is the RF spring and roller for a laser distance flange reader. That sends information to the RF patch thus causing it to move.

You send all your lenses in to Leica for them to install a bit of paint on the flange which catches the lasers view.

The camera can also double as a weapon if you get mugged. Just remove the lens and point the camera at your attackers eyes.

:D

All jokes aside, I've been thinking about the laser idea for a while. Seems more likely that Leica will just go EVF if anything at all.
 

jonoslack

Active member
To me this sounds way to complicated to become truth.
HI Tom - I"m with you there
Over the years I came to the conclusion that the M system works best for
lenses 50mm and smaller
f2.0 and slower
Thats why I dont use/own the superfast M lenses any more. FOr super shallow DOF SLRs and AF cams work better IMO. Just to many factoes which can lead to focus inaccuracy of rangefinder: mechanical parts lens, mechanical parts camera, coupling, focus shift, optical parts camera, optical parts lens
pretty impressive how good it works anyways
Hmmm - I've borrowed Cam's lovely 75 'lux recently, and the hit rate on focusing wide open is still more to my taste than any AF lens - and I've no problem focusing 90mm lenses with the M either. . . . . maybe you need to practice a little :p

The other problem with an EVF is that it'll show you the whole area of the lens . . . . so, no more framelines . . in which case you may as well just cut the crap and get an A7. I don't see the mileage in an M camera with only an EVF.
 

Knorp

Well-known member
Hmmm - I've borrowed Cam's lovely 75 'lux recently, and the hit rate on focusing wide open is still more to my taste than any AF lens - and I've no problem focusing 90mm lenses with the M either. . . . . maybe you need to practice a little :p
+1 I've always been pretty pleased with my hit rate with both 75AA and 75Lux. The 90AA wasn't bad either.
The 135AT was more of a challenge OTOH IMO.

Practice is key though !

All the best.
 

aDam007

New member
HI Tom - I"m with you there

Hmmm - I've borrowed Cam's lovely 75 'lux recently, and the hit rate on focusing wide open is still more to my taste than any AF lens - and I've no problem focusing 90mm lenses with the M either. . . . . maybe you need to practice a little :p

The other problem with an EVF is that it'll show you the whole area of the lens . . . . so, no more framelines . . in which case you may as well just cut the crap and get an A7. I don't see the mileage in an M camera with only an EVF.

Yeah, hit rate isn't an issue for me either. I shoot with two bodies and a 35FLE and 75APO for weddings and I think I miss critical focus on 1-2 out of every 10 shots. It's really not that difficult, until your RF fails. Then the hit rate goes to 0 really quickly. I've had this happen during a wedding for no reason, which is why I carry four M240 bodies with me (now 3, since I sold my silver unit due to disliking the color). But when it works, it's faster and more accurate then my time with the D4 or my current 1Dx and 5D3.

I use a lot of lenses and out of all those lenses, the 90APO is the most difficult to focus due to two reasons. 1) My eyes can't see that minute detail at the distance I shoot it, and 2) the frame lines are really off even after sending all my cameras in TWICE to THREE times.
The 50LUX is the second most difficult because of the field curve wave. Mid zone dip whatever you call it. Focusing and recomposing with that lens can be a hassle, even worse then focusing the Noctilux, which is difficult because of 0.95 DOF.
Aside from the above mentioned "problem" lenses, I rarely if ever have a issue with focusing. Mind you, I sleep with the M240+50APO under my pillow. My wife calls it my mistress, since I give it more attention then her :D LOTS of practice focusing it.
 

Paratom

Well-known member
HI Tom - I"m with you there

Hmmm - I've borrowed Cam's lovely 75 'lux recently, and the hit rate on focusing wide open is still more to my taste than any AF lens ...
Hi Jono,
maybe thats because you have resisted the S system ;)
Anyways, some lenses seem more problematic than others.
At least my fav lenses (21/3.4,35/1.4FLE,35 Summicron asph, 50APO and 75 Summicron (this one is correct but not easy to focus due to its sharpness and abrupt transition)) all work great on my M body. Also the 90/2.8 - for some reason has worked great on all my m-bodies. While my 50/1.4asph seems to need focus calibration for each M-body.
And I do think many images floating in the internet from the Noctilux wide open do have a special look and character but often focus is not that accurate (on the eyes for example). Often not problematic/most important thing for an image but still I like to have that under control.
 

250swb

Member
I can't help but think making the camera adjust to an inaccurate lens is a short sighted way to go about this. Lens manufacturers presumably want to sell M compatible lenses, and while Leica themselves are addressing the tolerances needed for digital others may not be. So to get your lens to work on an M9 you need to be talking to Cosina (kills the Zeiss bird with the same stone) not designing a camera to work with crappy lenses. Encourage manufacturers to make sloppy tolerances would also mean they may even be/become inaccurate for film cameras and you are paying for less effort on their part.

And if you are only addressing the second hand market then inaccuracy has had a solution since Leica introduced the 35mm camera, send the lens to be calibrated properly. If you can't be bothered to do that it shouldn't need a new camera designing. And do we really want a second hand lens market where inaccurate lenses are encouraged?

Steve
 

Paratom

Well-known member
I can't help but think making the camera adjust to an inaccurate lens is a short sighted way to go about this. Lens manufacturers presumably want to sell M compatible lenses, and while Leica themselves are addressing the tolerances needed for digital others may not be. So to get your lens to work on an M9 you need to be talking to Cosina (kills the Zeiss bird with the same stone) not designing a camera to work with crappy lenses. Encourage manufacturers to make sloppy tolerances would also mean they may even be/become inaccurate for film cameras and you are paying for less effort on their part.

And if you are only addressing the second hand market then inaccuracy has had a solution since Leica introduced the 35mm camera, send the lens to be calibrated properly. If you can't be bothered to do that it shouldn't need a new camera designing. And do we really want a second hand lens market where inaccurate lenses are encouraged?

Steve
I have had brand new Leica lens where my first action was to have to send it in for focus-calibration. And Leica themselve suggest to send in lens with body for best results.
 
V

Vivek

Guest
Having had an M9, but living in a country with no access to Leica services, I got more and more uncomfortable with the rangefinder calibration issue as the number of my lenses grew. I finally sold the M9 and have been using mirrorless cameras since.

With growing sensor resolution, the mechanical rangefinder-lens coupling is becoming a serious limiting factor.

Now, I was wondering if this could not be solved by replacing this mechanical by an electronic coupling. The position of the rangefinder roller, moved by the rangefinder helix of the lens as the focusing ring is turned, would be electronically measured. This measured position would then trigger the adjustment of the position of the rangefinder patch, for example using a servo or a digitally produced patch in an arrangement similar to the one used in the Fuji X-Pro1.

The obvious advantage of this is that no mechanical adjustment or calibration is required. Both RF roller and RF patch would never need to be adjusted after initial build of the camera. All adjustments and calibration could be done via software using a calibration profile for every camera-lens couple. This calibration could even be done by the enduser with the help of an EVF and a software supported procedure.

So one would set a calibration profile for every lens he wants to use on his camera, and the camera would upload the corresponding profile every time the lens is mounted. For lenses with strong focus shift, the owner of the camera could also choose at what aperture the calibration is done, depending on his preferences.

If this is possible, the list of improvements would be long, among them:
- software calibration allows to perfectly calibrate a camera with an unlimited number of lenses, which is very hard to do with a mechanical coupling
- in the field calibration is possible, with no risk of damage
- as the RF roller is not adjustable, the calibration will not be lost du to excessive vibration or mechanical shock
- focus shift can be taken into account
- etc.

Again, if this is possible, one would have the pleasure of using rangefinder focussing without the hassle of maintaining mechanical calibration.

If this has already been suggested or discussed elsewhere, don’t bother, but if not, I would be happy to have your opinion about the idea.
No need for any coupling of any sort. Just make use of the liveview and integrate an EVF.
 

jonoslack

Active member
I have had brand new Leica lens where my first action was to have to send it in for focus-calibration. And Leica themselve suggest to send in lens with body for best results.
Do they still suggest this with the M240 Tom? - I thought they'd changed their tune.
 

jonoslack

Active member
No need for any coupling of any sort. Just make use of the liveview and integrate an EVF.
. . . and then realise other cameras have better EVFs and get rid of the rangefinder altogether!
The reason for shooting with a rangefinder is to be able to see outside the image and to use rangefinder focusing . . . no point in having one at all if you don't want to do that!
 
V

Vivek

Guest
. . . and then realise other cameras have better EVFs and get rid of the rangefinder altogether!
The reason for shooting with a rangefinder is to be able to see outside the image and to use rangefinder focusing . . . no point in having one at all if you don't want to do that!
Does anyone shoot videos with the rangefinder focusing?
 

Paratom

Well-known member
. . . and then realise other cameras have better EVFs and get rid of the rangefinder altogether!
The reason for shooting with a rangefinder is to be able to see outside the image and to use rangefinder focusing . . . no point in having one at all if you don't want to do that!
I think it is also one of the best focus aids available today for wideangle to normal focal lengths. For me focus peaking doesnt cut it, and focus magnification is great for still but not for people.
Seeing outside the image is also a great feature IMO.
 
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