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Archive 2019 · Mirrorless to Rangefinder transition

  
 
AcuteShadows
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p.1 #1 · Mirrorless to Rangefinder transition


I'm currently trying to get rid of using the zoom on my Z7 for manual focusing. I think I'm having some success with the Summarit lenses, and my goal is not necessarily to be able to correctly focus on the eye rather than the eyelashes when using manual focus without using the zoom function.

Would it be harder or easier to focus accurately on a rangefinder camera (such as the Leica M Typ 240) than on the Nikon Z7 (without zoom), say at f/2 or f/2.4 for a typical head and shoulders portrait magnification (and resulting depth of field)? How much scope is there to improve your focusing skills, and what is a reasonable expectation on what is possible for someone who's willing to put in some effort but probably does not have exceptional skills?

(I'm not planning to drop my Z6 and Z7, but I may add a used Leica for travel and occasional use.)



Nov 14, 2019 at 07:26 PM
rscheffler
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p.1 #2 · Mirrorless to Rangefinder transition


What lens(es) do you have in mind? Ease of consistently hitting wide open focus with rangefinder cameras become progressively more difficult the longer the focal length.

I don't know how good the Nikon EVFs are compared to something like the first SL, with which I found I could pretty consistently hit correct manual focus with fast lenses ~50mm and longer without use of any focusing aids (this was strictly based on spending ~1 hour with an SL trying my various rangefinder lenses).

Hitting wide open focus with a rangefinder is not only dependent on how well you can see the rangefinder patches align, due to your eyesight, it will also depend on the calibration of the camera and the lenses. From my experience after ~9 years with an M9 and M240, it's nearly impossible to have the camera and all lenses perfectly calibrated. Instead what usually happens, at least for me, is I learn each lens's 'quirks' with the camera. For example, if a lens consistently back focuses, I do focus bracketing test shots at various distances intentionally front focusing in small increments (based on the coincidence of the rangefinder patches), checking the results in-camera and then remembering what the 'offset' of the coincidence was whenever I'm using that lens. This might seem like a hassle, but in practice I've found it works pretty well. Some advocate the use of eyepiece magnifiers, particularly with 75mm or 90mm lenses. I've tried this too, but didn't really find it helpful. Unless you dedicate one camera to one lens, if you're like me and switch lenses a lot while out shooting, it's a considerable hassle to screw and unscrew the magnifier to/from the eyepiece. I found getting the correct eyepiece diopter for my eyesight was much, much more helpful at achieving consistent focus.

With a fast lens, such as a 50/1.4 at portrait distances, I'm pretty confident at getting correct wide open focus, if the point of focus is centrally located. The 90/2 AA is a bit trickier, but it also has a reputation of being very difficult for Leica to correctly calibrate across its full range of focus. If you like to consistently place your subject off center, it gets more complicated with a rangefinder camera because of the tilt/shift of the plane of focus whenever you focus and recompose, particularly at closer distances and with wider angle lenses. Complicating this will also be the field curvature characteristics of each lens. For example, due to the 28 Cron v1's plane of focus curving away from the camera the farther from the center of the image, I would always have to front focus it (relative to correct rangefinder coincidence) for correctly focused off-center subjects when shooting relatively wide open.

Where I have found the rangefinder focusing system the best of any focusing system I've tried so far, is more so with lenses ~35mm and wider. I could never be confident of correct focus of wide angle lenses by eye with SLRs and also found that SLR/DSLR AF systems were often frustratingly inconsistent the wider the lens. It's one of the primary reasons I got the M9 back in 2010 and in this respect have been very happy. Another aspect is that the degree of alignment of the rangefinder image gives you a very fast ballpark idea of how near or far off focus is at any moment. Therefore, if you're shooting wide open, you will work harder at getting correct rangefinder coincidence. But if you're shooting stopped down, you know that depth of field will cover minor focusing errors. This can help in fluid situations because you don't have to stress about perfect rangefinder coincidence yet you will have a very clear idea of how close you are to perfect focus. IMO, this is where mirrorless has disadvantages when shooting stopped down, in that it's very difficult to discern where the exact plane of focus is in the EVF image, especially without use of magnification.

My mirrorless experience is considerably less than with DSLRs or rangefinders, but so far I've found that focus peaking is almost worthless with wide angle lenses and/or when shooting stopped down, because nearly everything in the image ends up swimming in peaking artifacts. Focus magnification is too time consuming if trying to photograph non-static subjects... so I can appreciate where you're coming from. In that respect, if non-static subjects are a good portion of what you photograph with mirrorless, I'd probably stick with native AF lenses.



Nov 14, 2019 at 11:07 PM
pmeheut
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p.1 #3 · Mirrorless to Rangefinder transition


AcuteShadows wrote:
Would it be harder or easier to focus accurately on a rangefinder camera (such as the Leica M Typ 240) than on the Nikon Z7 (without zoom), say at f/2 or f/2.4 for a typical head and shoulders portrait magnification (and resulting depth of field)?


rscheffler said it all.

Using a rangefinder for portraits wide-open is possible but even after 30 years with a Leica M as my primary camera, this would not be my first choice.
And getting the kind of precision you want is sometimes possible depending on your eyes (and age), perfect camera & lens calibration but I would not bet on it.






Nov 15, 2019 at 12:49 AM
zhangyue
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p.1 #4 · Mirrorless to Rangefinder transition


I have better luck with my M set since M240. All my lenses and camera are in sync right now include difficult one 75lux and 90APO. Consistent nail focus with 90APO is different story. However, I have no issue nail focus with 50mm below wide open, at any distance and at f1.4. Your 50APO is even easier.

The experience is different than EVF shooting. I would say with A Match set of camera and lenses, the experience is really enjoyable.

As you can see, the answer is quite different when you ask different people.

The only way to find out is buy it and try. M lens is only worth its price on M camera if you ask me, I know it is a little extreme, but that is how I view it.



Nov 15, 2019 at 01:39 AM
AcuteShadows
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p.1 #5 · Mirrorless to Rangefinder transition


Thank you all for your feedback!

I have the following Leica lenses, which would be in my small (i.e. mini) travel kit:
- Summicron 2/28mm (current version)
- Summarit 2.4/50mm
- Summarit 2.4/90mm
I may add SEM 3.4/21mm and/or Summicron 2/75mm at a later time.
That would be the focal lengths that I'm looking at, with the Summicron 75mm probably the most critical.

Currently, I'm using the lenses with my Z6 and Z7 with adapter. Resolution is fine, but I need to apply a color cast profile in a post-processing program such as Capture One. I would like to avoid having to use a computer before uploading the first images to social media, and I hope that the rangefinder may be better than mirrorless without zoom (and faster than mirrorless with zoom).

I think that my eyesight is fine. Given rscheffler's feedback, it seems that carrying an external EVF with me would be a good idea.

I'll check how good the rangefinder is with locating the focus plane, that indeed can be somewhat tricky on mirrorless.

Given that the lenses I'll be using are new and I'll not be using them that often, there is maybe a better chance that they are actually not causing issues with rangefinder alignment. It's probably important to know that this may be a serious issue.

I don't think I'll use off-center focus for shallow depth of field often, and in many such instances, I'll have more time to acquire focus or to shoot multiple pictures.

Non-static subjects would not be my priority with rangefinder, though I've taken pictures of speakers with f/2.4 (their range of movement is probably 5-10x depth of field, depending on final resolution requirements).

Given that it's likely that I need a good EVF just in case, I might wait until M10 used prices drop further. SL2 looks like a good proposition too (not a rangefinder, of course), yet size reduction is quite limited with regard to Nikon Z.




Nov 15, 2019 at 07:11 AM
rscheffler
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p.1 #6 · Mirrorless to Rangefinder transition


I would recommend the external EVF for the M240 (or M10) for those times when you want to be absolutely sure about focus and have the time to do so, but then you're back to the same 'problem' of EVF mirrorless focusing. It's also a great tool to immediately know if rangefinder calibration for a given lens is accurate: focus with the EVF on a clear, high contrast target, then look through the OVF to see if the rangefinder patch is aligned. If not, and you do this multiple times with similar results, then you know by how much you need to 'mis-focus' through the OVF to get proper focus.

IMO, once you get to know your lenses via rangefinder shooting and are comfortable with any quirks, it becomes very intuitive. I think when starting with rangefinder, it's too easy to get hung up on perfect rangefinder coincidence. I see it when I hand the camera to friends - they spend ages twiddling with the focus back and forth.

On paper the SL2 seems like the best mirrorless for adapting M lenses and the EVF might be good enough for focusing fast lenses wide open with confidence. But it will still have the same problems as any other mirrorless when it comes to properly placing the plane of focus when shooting stopped down - you won't be able to see the best point of focus without magnification. Peaking will be useless because of too many 'false-positive' peaking artifacts. At 47MP you can bet that even at f/5.6 depth of field will not be sufficiently forgiving at covering missed focus, even with wide angle lenses.

Something else that came to mind about rangefinder focusing certain lenses, particularly the telephotos is the 'throw' or pitch of the helicoid/focusing ring. One of the easiest to focus RF teles, IMO, was the ZM85/2, which had a variable pitch focusing cam (if that's the right term?), where the focusing throw was longer at farther distances. A long throw means easier focus fine tuning but at the expense of quickness. Short throw lenses let you rack focus and very quickly get in the ballpark, but are not as good for fine focus adjustments, particularly if longer fast lenses. Another lens I found easy to RF focus was the old Nikkor 105/2.5, with roughly 330 degree throw from infinity to MFD, but it was very slow to focus in non-static situations. In contrast the 90/2.5 (or 2.4) Summarit had a short throw and was more finicky. The 90AA, while the throw might be roughly similar to the Summarit, in degrees, is a larger diameter lens and the longer actual distance of movement of the focusing ring allows for easier fine adjustments. I've only briefly used the 50/1 and 75/1.4 but found both relatively easy to rangefinder focus, probably in part because both were larger diameter lenses.

Most of the newer M lenses have shorter focus throws which make them quick to rack the focus and get in the ballpark. IMO, this helps make M cameras quick to shoot when anticipating shots moments before they happen. Speed will also be dependent on how shooting aperture and the resulting depth of field is combined with getting rangefinder alignment 'in the ballpark' to achieve acceptable, if not technically perfect focus. I feel this is one of the core aspects of working with M cameras. But it seems nowadays everyone shoots wide open and is obsessed by technically perfect focus...



Nov 15, 2019 at 09:40 PM
AcuteShadows
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p.1 #7 · Mirrorless to Rangefinder transition


"Obsessed by technically perfect focus"... count me in. I kind of see small differences in sharpness that draw my eye to the sharpest point, even stepped down and well within what would be acceptable sharpness were it not for that one spot that is even sharper with todays lenses and sensors.

Thank you for pointing out that the EVF also helps with a misaligned rangefinder! I think I would need the M10, as it offers a better external EVF solution than the M (Typ 240). I have no problems using the EVF when necessary, but would like to save space and, if possible, weight when I do not need it.

The focus mechanism of the M lenses I own is exceptionally smooth and responsive, so I actually prefer the shorter focus throw. For longer focus throw, I have the Zeiss Milvus lenses.

I'm not using peaking because I get a sea of color right at the spot that I need to look at in order to acquire focus.


rscheffler wrote:
I would recommend the external EVF for the M240 (or M10) for those times when you want to be absolutely sure about focus and have the time to do so, but then you're back to the same 'problem' of EVF mirrorless focusing. It's also a great tool to immediately know if rangefinder calibration for a given lens is accurate: focus with the EVF on a clear, high contrast target, then look through the OVF to see if the rangefinder patch is aligned. If not, and you do this multiple times with similar results, then you know by how much you
...Show more



Nov 15, 2019 at 10:26 PM
pmeheut
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p.1 #8 · Mirrorless to Rangefinder transition


BTW, I did a test so I focused on the eye using only the rangefinder.
I used the 90mm/2.8 Elmarit and the 50mm/1.2 Voigt, both wide-open. The 50mm is not perfectly calibrated and you can see a slight front-focus.
Light was low, 1000 ISO, 1/125 & f/1.2 for the 50mm, 6400 ISO, 1/125 & f/2.8 for the 90mm.

As you can see, focusing precision is very good but if the subject moves, or if I move or I'm not concentrated or I reframe too much, my success rate goes down.


.



Nov 16, 2019 at 11:41 AM
Rob L
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p.1 #9 · Mirrorless to Rangefinder transition


I have very good success with fast lenses wider than 50mm partly because with normal and wide lenses, I am naturally going to be closer to the subject and the image in the viewfinder will be larger and easier to see. Often this is not the case with lenses 75mm and above. My cameras are perfectly calibrated in the vertical dimension and I look for a clear image in the patch or better yet focus on a refection or catch-light in the eye.


Nov 16, 2019 at 12:43 PM
rscheffler
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p.1 #10 · Mirrorless to Rangefinder transition


Indeed the M240 EVF is not great resolution and the image becomes a bit smeary at higher ISOs. I have not tried the M10 & EVF to determine how much better it is. But the M10 is definitely an improvement over the M240 in terms of electronics and fewer quirks. IIRC, it will also allow you to magnify focus off center, whereas the M240 is center only magnification.

The M240 EVF at least is not that large and very easy to pack. I actually use it more for precise composition when required with wide angle lenses, or to eliminate the slight parallax error of the RF system when it comes to image composition. In these cases I'll usually RF focus and then compose in the EVF. IMO, this is an extremely fast way to manually focus a live view camera, assuming good RF calibration.


AcuteShadows wrote:
"Obsessed by technically perfect focus"... count me in. I kind of see small differences in sharpness that draw my eye to the sharpest point, even stepped down and well within what would be acceptable sharpness were it not for that one spot that is even sharper with todays lenses and sensors.

Thank you for pointing out that the EVF also helps with a misaligned rangefinder! I think I would need the M10, as it offers a better external EVF solution than the M (Typ 240). I have no problems using the EVF when necessary, but would like to save space
...Show more




Nov 18, 2019 at 12:49 PM
LBJ2
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p.1 #11 · Mirrorless to Rangefinder transition


I shoot both Sony mirrorless and Leica M10. I decided to try a real adapter for my M glass a some point and thought I would try the M10...that little experiment quickly turned into an expensive/torrid love affair with the Leica M system.

With a little bit of practice with both the Rangefinder and Zone Focusing, I can now get just about any shot I want/need. The M system IMO is also optimized for zone focusing too and like many before me, I found focusing can be even faster than Sony AF at times. I do need to wear my specs for RF and found I need to keep the viewfinder window very clean for precise focusing. FWIW I honed my Zone Focusing using a pocket size Bosch GLM 20 Compact Blaze 65' Laser Distance Measure. Seemed to wok for me. Ha Ha.

Here I am having some fun on the street with M10 + Noctilux 50 f0,95 @ 0,95 using RF.

https://www.dpreview.com/forums/post/62539886?image=0




Nov 18, 2019 at 01:22 PM
retrofocus
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p.1 #12 · Mirrorless to Rangefinder transition


LBJ2 wrote:
I shoot both Sony mirrorless and Leica M10. I decided to try a real adapter for my M glass a some point and thought I would try the M10...that little experiment quickly turned into an expensive/torrid love affair with the Leica M system.

With a little bit of practice with both the Rangefinder and Zone Focusing, I can now get just about any shot I want/need. The M system IMO is also optimized for zone focusing too and like many before me, I found focusing can be even faster than Sony AF at times. I do need to wear my specs
...Show more

I agree with your sentiments - even I haven't used a digital M yet, I can confirm your points from several Leica rangefinder film cameras which I am using. I am faster and focus is more reliable with rangefinder and/or zone focusing compared to using the same lenses on my A7R. I also found that a dirty rangefinder window makes focusing with a rangefinder camera by looking through the viewfinder very hard - and the position of the window is in a spot where I often like to touch with my finger when handling the camera!
Fastest rangefinder lens for focusing is indeed a slow one - the CV 25/4.0 Snapshot-Skopar LTM lens. It has no rangefinder coupling, but its combination of FL and metering stops makes focusing very reliable even at faster aperture numbers. I just have to estimate the distance in a range of short, middle or long, and I always nail the focus in an instant. It's the smallest 25 mm lens made, and it is incredibly sharp corner to corner. I compose with the CV 21/25 II external viewfinder. This lens just does not work well at all attached on my A7R.



Nov 18, 2019 at 01:42 PM
Steve Spencer
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p.1 #13 · Mirrorless to Rangefinder transition


LBJ2 wrote:
I shoot both Sony mirrorless and Leica M10. I decided to try a real adapter for my M glass a some point and thought I would try the M10...that little experiment quickly turned into an expensive/torrid love affair with the Leica M system.

With a little bit of practice with both the Rangefinder and Zone Focusing, I can now get just about any shot I want/need. The M system IMO is also optimized for zone focusing too and like many before me, I found focusing can be even faster than Sony AF at times. I do need to wear my specs
...Show more

Really lovely images and show exactly what that combination can do.



Nov 18, 2019 at 02:13 PM
rscheffler
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p.1 #14 · Mirrorless to Rangefinder transition


retrofocus wrote:
Fastest rangefinder lens for focusing is indeed a slow one - the CV 25/4.0 Snapshot-Skopar LTM lens. It has no rangefinder coupling, but its combination of FL and metering stops makes focusing very reliable even at faster aperture numbers. I just have to estimate the distance in a range of short, middle or long, and I always nail the focus in an instant. It's the smallest 25 mm lens made, and it is incredibly sharp corner to corner. I compose with the CV 21/25 II external viewfinder. This lens just does not work well at all attached on my A7R.


IIRC that lens is also problematic at least on the M9, but not sure how well the M240 or M10 handle it for edge color shift. I have the CV 12/5.6 v1 and it color shifts on the M240, though is usually fixable in Lightroom with a color gradation overlay.

I agree these wide and slow lenses are easy to pre-focus, which is a very useful technique with rangefinder cameras. Most of my RF shooting is stopped down wider lenses (up to 50mm). Focusing is just a matter of closely aligning the RF patch and not worrying much about perfect coincidence. That might change somewhat if the M ever ends up at 47MP or higher where correct focus within the narrower available depth of field, if not downscaling, will be more critical.



Nov 18, 2019 at 05:46 PM
d.s.
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p.1 #15 · Mirrorless to Rangefinder transition




AcuteShadows wrote:
Would it be harder or easier to focus accurately on a rangefinder camera (such as the Leica M Typ 240) than on the Nikon Z7 (without zoom), say at f/2 or f/2.4 for a typical head and shoulders portrait magnification (and resulting depth of field)? How much scope is there to improve your focusing skills, and what is a reasonable expectation on what is possible for someone who's willing to put in some effort but probably does not have exceptional skills?



Wide open and without the EVF, with typical head and shoulders portraits using a rangefinder you'll need to learn how much field curvature your lens has in order adjust appropriately the focus adjustment you already need to make when focusing on your subject's eyes before tilting the camera back down to their wherever. It's easy enough, but mostly when they sit still, move left, or right.

In case you're not familiar, I recommend searching rangefinderforum.com for "cosine effect." At least one result should provide a visual explanation in the context of some M mount lenses.





Nov 18, 2019 at 10:24 PM
retrofocus
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p.1 #16 · Mirrorless to Rangefinder transition


rscheffler wrote:
IIRC that lens is also problematic at least on the M9, but not sure how well the M240 or M10 handle it for edge color shift. I have the CV 12/5.6 v1 and it color shifts on the M240, though is usually fixable in Lightroom with a color gradation overlay.

I agree these wide and slow lenses are easy to pre-focus, which is a very useful technique with rangefinder cameras. Most of my RF shooting is stopped down wider lenses (up to 50mm). Focusing is just a matter of closely aligning the RF patch and not worrying much about perfect coincidence.
...Show more

Interesting - up to now I always assumed that all LTM and M-lenses work on all variety of digital Leica cameras, too. Thanks for clarifying this! This could be the reason why this lens is priced "only" about $200 in the used market. I always assumed the CV 12/5.6 would work fine on digital Leica cameras, too - I observe the same when using my CV 12/5.6 II on the A7R. I use Adobe Flat Field DNG with own calibration files to remove the color casts. Also agree that lower resolution sensors and 35 mm film are more "forgiving" for focus. It is one reason why I am using film for street photography.



Nov 19, 2019 at 07:24 AM
RustyBug
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p.1 #17 · Mirrorless to Rangefinder transition


Interesting read ...

Some .02 from the uninitiated in digital RF.

With all the MILC vibe going around theses days, it was good to hear others mention that peaking becomes a blob of a mess when chasing critical focus where you have significant DOF (FL or Aperture). In effect, it becomes a "range of focus points" itself.

I haven't used RF, since I got my first camera (Yashica 50/1.4) and yearned for the precision of focus from the SLR (microprism / split ring / matte). There was something nice about having a flick of the wrist and the image "pop" into focus on the different screens when I needed.

In reading this thread, it strikes me that the rangefinder approach is aptly named. In which, the approach lends itself to expediently finding a range (which is acceptable) of focus. Then main reason that I went away from the rangefinder in my youth, was the quest for critical focus vs. the ranged focus approach (and parallax for near subjects).

While we can certainly appreciate the mark of precise focus (I'm a junkie, too.) I tend to think that expecting a tool designed for its expedient approach (prevalence of intended application) to achieve such a precision point of focus should come with the understanding that one is going to trade off the expedient use of zone dof for an encumbrance (speed loss, viewing aid, mag / zoom view, etc.) to garner maximum precision. Imo, this is simply a matter of expecting a tool to do something other than it was designed to do.

That's not saying it can't do it ... just that it wasn't designed to do it optimally, and it will incur a reduction in expedience in order to achieve such a "precise" focus, rather than a "ranged" focus.

Imo, for a given FL / distance > DOF application, shooting uber-narrow DOF with extreme precision is understood to be a slower process than shooting a more modest DOF. 1.4 at 3 feet vs. 1.4 at 10 feet, one provides for more dof range than the other. So, if I'm shooting at 3 feet, maybe I should be at 1.8 or 2.0 in order to retain the "range", such that I retain the expedience.

Imo, it's a tradeoff between expedience of range finding vs. precision focus. I realize I haven't said anything that the vast knowledge of experienced RF users don't already know ... just that sometimes we have unrealistic expectations that go against the intended design of a given tool. Again, not that it can't be achieved, but maybe a revision of expectation is in order regarding the process for doing so. We always want our cake and to eat it too ...

Just some ramblings, hopefully there's a nugget in there somewhere for ya.

I think I'll use a chainsaw for surgery, or maybe a scalpel to cut some firewood. I'm sure either can be achieved with the right amount of applied effort & tenacity.

Using a camera designed for expediently finding a range of focus to precisely attain uber-critical focus manually ... hmmmm, let me think about that one for a moment.

Personally, given the depth of the human face ... focusing difference between eyelash vs. eye vs. brow vs. nose requires enough DOF to readily cover both the lash & eye, rather than so small as to separate the two. Never mind the variance in planes from different pose / shooting angle. But, that's just a thought from someone who isn't shooting eyelashes & eyeballs much these days.








Nov 19, 2019 at 09:06 AM
wolfloid
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p.1 #18 · Mirrorless to Rangefinder transition


The Yashica would have had a very narrow rangefinder base, which cannot compare to Leica rangefinders, which are inherently much more accurate. As a primarily environmental portrait/street photographer I changed from an excellent Pentax LX to a Leica M6 for much more accurate and quicker focusing for lenses between 24-50 mm. I think that is what most here have also been confirming.

Your theory of 'getting in range' is your own interpretation and it probably held good for the Yashica, but a good rangefinder was and still is a very accurate device when accurately calibrated. SLR focusing is only better and faster beyond about 75mm.



Nov 19, 2019 at 04:35 PM
philip_pj
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p.1 #19 · Mirrorless to Rangefinder transition


Reading about the development of the Leica 50mm APO-Summicron-M asph f/2.0, there is the impression that the M cameras assist in lens development by working best with lenses that have very high performance - giving a very narrow, high contrast focal plane - which snaps into focus more readily *because OOF areas are lower in contrast*.

“From infinity to the focus point the contrast becomes better and better, and then it falls off after the focus point. We don’t talk about a maximum contrast or if it is 92% or 95% or 85%. That is not the big issue.“ “The big issue is how the contrast falls off out of focus. It has to fall off fast, ideally.” “This is the contrast behavior of the old Summicron, and this” – he draws a pyramid in the air with his finger – “is the new APO-Summicron.” - Peter Karbe interview with Thorsten Overgaard.

and

“Ultra-high performance lenses are more troublesome than designing lenses with normal performance. If the resolution is high, the focus will rise. The width of the in-focus area will also be narrowed. Manufacturing error affects the performance and it is difficult to actually make it, so there is a need for .. performance even at the factory." - Shimada-san, Cosina lens designer (65/2, 50/2)

But with regard to the modern fetish for huge element count even in near-normal lenses (the latest Sigma 35/1.2 is a 17/12, 82mm filter behemoth, adding all of 1090g to an E camera's carry weight):

"In some other designs you will find strong lens elements, and when you combine them you will get a sharp lens. But each element will contribute strong aberrations. So traditionally other lens designers will try to reduce aberrations with other elements." - Peter Karbe

[Low contrast bokeh and smooth transition zones are obviously an aficionado matter these days. A glance at many image threads will show that the 'modern' bokeh is at least as visually prominent in the image presentation as the in-focus material. Not necessarily a judgment on artistic expression (because it can add impact and context to the image), but an observation that new trends can be taken to extremes.]



Nov 19, 2019 at 07:03 PM
rscheffler
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p.1 #20 · Mirrorless to Rangefinder transition


retrofocus wrote:
Fastest rangefinder lens for focusing is indeed a slow one - the CV 25/4.0 Snapshot-Skopar LTM lens. It has no rangefinder coupling, but its combination of FL and metering stops makes focusing very reliable even at faster aperture numbers. I just have to estimate the distance in a range of short, middle or long, and I always nail the focus in an instant. It's the smallest 25 mm lens made, and it is incredibly sharp corner to corner. I compose with the CV 21/25 II external viewfinder. This lens just does not work well at all attached on my A7R.

rscheffler wrote:
IIRC that lens is also problematic at least on the M9, but not sure how well the M240 or M10 handle it for edge color shift. I have the CV 12/5.6 v1 and it color shifts on the M240, though is usually fixable in Lightroom with a color gradation overlay.

I agree these wide and slow lenses are easy to pre-focus, which is a very useful technique with rangefinder cameras. Most of my RF shooting is stopped down wider lenses (up to 50mm). Focusing is just a matter of closely aligning the RF patch and not worrying much about perfect coincidence.
...Show more
retrofocus wrote:
Interesting - up to now I always assumed that all LTM and M-lenses work on all variety of digital Leica cameras, too. Thanks for clarifying this! This could be the reason why this lens is priced "only" about $200 in the used market. I always assumed the CV 12/5.6 would work fine on digital Leica cameras, too - I observe the same when using my CV 12/5.6 II on the A7R. I use Adobe Flat Field DNG with own calibration files to remove the color casts. Also agree that lower resolution sensors and 35 mm film are more "forgiving" for
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There are definitely older LTM/M lenses that do not play well on digital Leica M cameras, in respect to edge color shifts. From my own experience and what I recall, these include a lot of the Voigtlander LTMs from the early 2000s, like the 12, 15, 21/4, 25/4. Also the ZM21/4.5, which is quite notoriously bad for color shift though it's an amazingly sharp lens. I had the ZM21/2.8 for quite some time and used it a lot with the M9, but had to apply CornerFix profile corrections to those files (basically the same thing as the Adobe Flat Field plug-in). A benefit of shooting newer Leica glass on digital Leica Ms is the color shift correction built into the camera. If you turn off lens detection via the 6-bit code, some lenses will result in fairly noticeable color shifts. For non-Leica lenses you can get approximate in-camera corrections by manually selecting a suitable lens code in the camera, or painting a simulated 6-bit code on the lens mount to trick the camera into automatically applying the desired corrections.



Nov 19, 2019 at 07:23 PM
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