oftheherd
Veteran
Indeed!!!!
sevo
Fokutorendaburando
Many of the SLR/AF=no rangefinder hypotheses brought forward in this thread are flawed, as they argue with general language definitions, which are indeed not specific ore relevant in photographic use.
The common definition of rangefinder in photography is "a manual optical distance finding mechanism other than viewing a projected lens image on a ground glass".
There is no common definition of rangefinder among the great unwashed. They may have discriminated between "rangefinder" (meaning anything with a see-through hole on top) and SLR ages ago, but my impression is that that stage in their camera categorisation ability was superseded by autofocus/manual some 25 years ago, and has now switched to "digital" vs. "bizarre ancient device". Given that none of those who asked for specifics on my camera seemed to associate anything with the term "rangefinder", it does not seem to be common use for non-SLR, non-AF or non-digital cameras in the UK and Ireland at least in recent times.
Sevo
Finder
Veteran
Contax G series and Hexar AF
pagpow
Well-known
Couple of points:
1) The academic is specifically referring to small format cameras -- no indication of whether small means miniature, sub-min etc -- just 35mm or anything under 120 size --
2) The academic is also compressing multiple unrelated dimensions of difference -- autofocus or manual, visual or not, showing distance or simply focusing, onto a single dimension -- through the lens or direct vision.
That collapsing of multiple dimensions of difference onto one creates the room for our interesting discussion -- which other might label confusion.
It seems to me that, in a academic text at least, and especially one focused on description, it might be worth capturing multiple dimensions of difference, at least three of which have figured prominently in this discussion --
one is means of focus -- geometric rangefinding, vs other distance measuring options, vs SLR focus (this last encompasses multiple methods itself, as the thread has already indicated)
two is provision for focusing -- w. at least three options (values) --
none, manual, auto
three is path of viewing -- w. at least two options, through the taking lens
(SLR) and one through a separate window (direct vision)
Reducing further confounds rather than explicates differences, no?
degruyl
Just this guy, you know?
Just for completeness (and there are a couple of examples, but not many in small format): Also, through a second, equivalent but fixed aperture lens (TLR).
View cameras could also be placed in the "through the taking lens" camp, but they do not exist in small format (as far as I know).
sevo
Fokutorendaburando
... or so their marketing would like us to believe. While they have a much wider base than other phase discriminating AF cameras, there is no reason to believe that they use any fundamental mechanism other than the PD used by all passive AF systems.
They positively do not make a visual 2D comparison to triangulate two video camera images, which would be a doubtlessly genuine rangefinder transformed to AF.
Gumby
Veteran
pagpow
Well-known
Bolded items in quotation bolded by me.
Couple of points:
1) The academic is specifically referring to small format cameras -- no indication of whether small means miniature, sub-min etc -- just 35mm or anything under 120 size --
2) The academic is also compressing multiple unrelated dimensions of difference -- autofocus or manual, visual or not, showing distance or simply focusing, onto a single dimension -- through the lens or direct vision.
That collapsing of multiple dimensions of difference onto one creates the room for our interesting discussion -- which other might label confusion.
It seems to me that, in a academic text at least, and especially one focused on description, it might be worth capturing multiple dimensions of difference, at least three of which have figured prominently in this discussion --
1) is means of measuring distance -- geometric rangefinding, vs other distance measuring options, vs SLR focus (this last encompasses multiple methods itself, as the thread has already indicated)
2) is provision for setting focus-- w. at least three options (values) --
none, manual, auto
3) is path of viewing -- w. at least two options, through the taking lens
(SLR) and one through a separate window (direct vision)
Reducing further confounds rather than explicates differences, no?
Also not clear from the supplied truncation whether author, not OP, is truncating the camera time line to exclude many classic cameras.
Roger Hicks
Veteran
KI (Kennedy Instruments) Monobar. There are surprisingly many 35mm TLRs, including the Tessina. There are also viewfinderless recording cameras (Leica Post) and surveillance cameras (Robot).
Without knowing more about the book and what she's trying to say, the conversation can't go much further, but the 'American academic' is likely to make herself a laughing-stock among photographers if she goes on like this. Not that ignorance, arrogance and a hidden agenda is necessarily a bar to widespread acceptance: look at Susan Sontag.
Cheers,
R.
Finder
Veteran
I would say you a splitting hairs--what does it matter if a human determines "phase contrast" or a machine? (Why would they lie in their marketing?)
karoron
Newbie
"The term was commonly used in geodetics and ballistics at least a century before the first photographic applications of on-camera rangefinders."
Very true and a good comment.
And they were all manual trigonometric measuring devices. The German term "entfernungsmesser" is sadly too broad in meaning for any differentiation between systems in use hundreds of years ago and much more recent technologies. As such, it is a somewhat useless term when discussing the intended concept of a rangefinder using English. It is very unlike German to lack such a technical differentiation IMHO.
Of course if we admit everything after the trigonometric distance measuring devices to the discussion then all of the hated slr cameras which use any form of manual or autofocus measuring systems are of course "rangefinders".
My comment as a surveyor who has used most of the listed technologies, using Swiss, German, and US made devices, was that the term "rangefinder" meant something specific to me.
Very true and a good comment.
And they were all manual trigonometric measuring devices. The German term "entfernungsmesser" is sadly too broad in meaning for any differentiation between systems in use hundreds of years ago and much more recent technologies. As such, it is a somewhat useless term when discussing the intended concept of a rangefinder using English. It is very unlike German to lack such a technical differentiation IMHO.
Of course if we admit everything after the trigonometric distance measuring devices to the discussion then all of the hated slr cameras which use any form of manual or autofocus measuring systems are of course "rangefinders".
My comment as a surveyor who has used most of the listed technologies, using Swiss, German, and US made devices, was that the term "rangefinder" meant something specific to me.
wolves3012
Veteran
My 2 cents-worth:
A rangefinder is a system for finding the range. In the case of a camera, that system is then used to adjust lens focus, whether automatically or manually and whether coupled or not. How the rangefinder works is, being picky, irrelevant but I'd say the triangulation of optical paths is the accepted idea. The rangefinder's purpose is to allow correct focus (hopefully!) and it does so indirectly, by measuring distance.
Most digital cameras do not find the range at all, they find correct focus by phase-contrast or similar means. They cannot be considered a rangefinder IMO. Focus-finder would be a more apt term but I don't see that coming into use!
Split-prism SLRs and the like, well that's a bit of a grey area. They don't really find the distance either, they find correct focus on the screen. I'd say they aren't rangefinders even in the looser sense.
A scale-focus camera could also be argued to be a rangefinder in a sense - the rangefinder is the human eyes estimating distance (no-one said the RF has to be accurate!). Extending that argument leads to the scale-focus + measuring tape idea. The rangefinder in that case is not built-in so I'd class neither as a rangefinder.
A rangefinder is a system for finding the range. In the case of a camera, that system is then used to adjust lens focus, whether automatically or manually and whether coupled or not. How the rangefinder works is, being picky, irrelevant but I'd say the triangulation of optical paths is the accepted idea. The rangefinder's purpose is to allow correct focus (hopefully!) and it does so indirectly, by measuring distance.
Most digital cameras do not find the range at all, they find correct focus by phase-contrast or similar means. They cannot be considered a rangefinder IMO. Focus-finder would be a more apt term but I don't see that coming into use!
Split-prism SLRs and the like, well that's a bit of a grey area. They don't really find the distance either, they find correct focus on the screen. I'd say they aren't rangefinders even in the looser sense.
A scale-focus camera could also be argued to be a rangefinder in a sense - the rangefinder is the human eyes estimating distance (no-one said the RF has to be accurate!). Extending that argument leads to the scale-focus + measuring tape idea. The rangefinder in that case is not built-in so I'd class neither as a rangefinder.
sevo
Fokutorendaburando
Technically wrong in either case - passive AF does use the same triangulation system as a rangefinder, all the PD does away with is the (eye or computer) visual comparison. And split prism screens are triangulating devices too, with the base their angle projected to the (virtual) lens pupil.
We'll really have to settle down to a definition that a rangefinder camera has a user-operated auxiliary rangefinder with independent optics.
wolves3012
Veteran
I did say "most digital". There are triangulation systems out there, I know. I can see your argument on split-prisms, but I'm not convinced either way, hence saying grey area (I should have said grey area in my mind).
dct
perpetual amateur
Today's digital RF, REAL rangefinders
Today's digital RF, REAL rangefinders
I suppport this point of view regarding the Contax G. Even if I don't have (yet) such a camera myself, the term "rangefinder" for this body is ok in the context of this forum here.
The active AF part relys on a trigonometric IR calculation (and VF feedback) of the distance of the object. The passive supporting AF part on a image difference of the two separate images, coming from the two separate AF optics. And it is definitly not TTL. The feedback for the user in MF is not a split-image patch, but a distance scale: Yes, this is the big difference to only MF rangefinders.
Of course, the photgrapher behind the camera makes the good shot, not the gear. But in my opinion I really don't understand why today's hype digital bodies like Fuji X100 (metering TTL, definitly not a RF camera) or the many NEX, m4/3 and similar approaches have such a big echo in this forum.
a) They mostly meter TTL.
b) they don't use separate optical/IR trigonometric metering system.
c) few of them feedback optically (or in a EVF) the range situation like a split-image patch or a range information.
Extending the thread to the question "What is a digital rangefinder?" what do we have today, which matches the discussion of last year of this thread?
I see only the discontinued Epson R-D1 models and the still available Leica M8 models and M9.
All the other digital stuff is very interesting, but:
I think they are all but rangefinder cameras.
Today's digital RF, REAL rangefinders
I suppport this point of view regarding the Contax G. Even if I don't have (yet) such a camera myself, the term "rangefinder" for this body is ok in the context of this forum here.
The active AF part relys on a trigonometric IR calculation (and VF feedback) of the distance of the object. The passive supporting AF part on a image difference of the two separate images, coming from the two separate AF optics. And it is definitly not TTL. The feedback for the user in MF is not a split-image patch, but a distance scale: Yes, this is the big difference to only MF rangefinders.
Of course, the photgrapher behind the camera makes the good shot, not the gear. But in my opinion I really don't understand why today's hype digital bodies like Fuji X100 (metering TTL, definitly not a RF camera) or the many NEX, m4/3 and similar approaches have such a big echo in this forum.
a) They mostly meter TTL.
b) they don't use separate optical/IR trigonometric metering system.
c) few of them feedback optically (or in a EVF) the range situation like a split-image patch or a range information.
Extending the thread to the question "What is a digital rangefinder?" what do we have today, which matches the discussion of last year of this thread?
I see only the discontinued Epson R-D1 models and the still available Leica M8 models and M9.
All the other digital stuff is very interesting, but:
I think they are all but rangefinder cameras.