What is a rangefinder?

[hanaa]

Okay... i had to ask. what is a rangefinder (i know it's a 35mm camera) but what does it do and what is it suited for.

thank you

 

[gnashings]

Well, a rangefinder is a device used for measuring distance (bear with me - I am not being a smart ass). The classic rangefinders (before radio waves and laser beams vs time methods were introduced) used the very basis of trigonometry - if you know the distance between two points, and the angles at which lines leaving those two points must take to intersect with a third point - you can easily calculate how far that thisrd point is. You may have seen documentaries where soldiers would look through funny looking binoculars with the front elements spread really far apart - those are rangefinders.
Now, you can apply the same principle to focusing a camera - you just need two points some distance apart that will capture an image, and a lens that will move in a predetermined relationship with them. A rangefinder contains a viewing window and another one that projects an image into your viewfinder. You see the image through the viewfinder, and a ghost image projected via mirrors (usually)by the other viewing port. By moving the focusing ring on the lens, you rotate the second element until the image it projects is lined up with the actual image you see. Because of the predetermined relationship between the two ports and the lens - at that point you are focused.
In practice you see what you normally see in a camera viewfinder, plus a ghost image - movin the focus moves the ghost image. Line 'em up and you're done. Its really, really simple and very quick! Most RF cameras require less than 2/3 of a rotation of the focus ring to cover their entire range, and you can tell how far off you are by how far apart you are with your ghost image.
There are many medium format cameras in the RF configuration, by the way, not just 35mm.

Now, you may ask - if its so wonderful, why aren't all cameras RF's? Well, I don't know, they should be Just kidding!!!
The adventages of the RF are as follows:
-very quick focusing
-no need for a space and weight consuming, not to mention noisy, mirror. This also allows you to generally shoot at slower shutter speeds because the vibrations resulting from the mirror moving up and down are eliminated.
-as a result of the above, small size and light weight and whisper quiet operation (street photgrapher love them for hteir stealthy ways!)
-there is no "black out" when the mirror is up, as in an SLR, so you can see everything, all the time.

The disadventages:
- you are not looking through the taking lens - so there is something called paralax to adjust for (the fact that you looking through a point removed by a few cenitmeters from the actual lens) as you can imagine, the closer you get, the more off you will be. Most good rf's correct for that by moving the viewfinder as you focus, but a) it only goes so far (its like crossing your eyes after a certain point) and b) it makes the camera not very useful for extreme close up work, also, when you change lenses, you have to use reference lines or separate viewers to adjust for their field of view, where in an SLR - you see what the lens sees - wide angle? you see all that wide angle. telephoto? you see that magnified image exactly the way the film will.
-many rangefinders use leaf shutters - while they have their adventages, they are generally not capable of the very high speeds of most focal place shutters in SLR's.

Between those two points, the SLR wins the popularity contest due to its versitility and ease of use (and ease of getting used to various applications).

OK - I hope that about covers, sorry about the long winded response!

Peter.

PS. You will most likely buy one sooner or later. They are cute, handy, charming, have personalities - you fall in love with them... its a sickness!!!

PPS. Here is a page that you may want to look at - this is a little known camera, but it is a classic rnagefinder layout, and there are many pictures which will hopefully help you make sense of my rambling (look at the picture of the camera with the top plate off to see more less how it works)

 

[David H. Bebbington]

Google reveals [almost] all:

http://en.wikipedia.org/wiki/Rangefinder_camera

Any further questions, get back to me! The article of course concentrates on photographic rangefinders of traditional optical/mechanical design (rotating silvered wedges). There are also large military rangefinders a couple of feet long and more, derivates of these for sportspeople, and all kinds of modern laser, infrared and ultrasound devices (for example, for measuring up rooms in houses).

Regards,

David

 

[Soeren]

In the wievfinder of a rangefinder you will see everything sharp no matter the distance. The SLR's prewievbutton allow you to see the DOF i.e. the area that looks sharp in the image. Thats vey usefull in closeups, macro work and when shooting a telelens.
Søren

 

[cvik]

Here is an image of how it looks on a Leica M6 (rangefinder camera).
Dead Link Removed

The framelines are always lighter than the rest and is used to compose the image (everything within will be part of the image, everything outside will not). The grey area in the middle is used for focusing. In this area you will see two overlapping images, one is part of the whole viewfinder image, and one is projected on top of it. The image on top moves from left to right when you focus. When the two images overlap the focus is correct.

and here is an image showing how the camera looks outside: http://www.adorama.com/images/Product/LCM772BK.JPG
The window to the right is the viewfinder image.
The middle window (grey) is used to make the frames lighter.
The left window is the small focusing area.
The distance between the left and the right window determines the accuracy of the rangefinder. Larger distance = better accuracy.

Here is an image showing how it works:
http://www.imx.nl/photosite/leica/technics/RFbasics/m6rf.jpg
The blue line is the whole image.
The yellow light is illuminates the frames so they will always be lighter than the image.
The red line is the small focusing image that is projected in the middle.

When you focus a small mirror is turned slightly so that the projected image moves within the finder.

 

[gnashings]

In the wievfinder of a rangefinder you will see everything sharp no matter the distance. The SLR's prewievbutton allow you to see the DOF i.e. the area that looks sharp in the image. Thats vey usefull in closeups, macro work and when shooting a telelens.
Søren

I knew I would forget something! Good point.

 

[Andy K]

Fun.

 

[rduraoc]

The middle window (grey) is used to make the frames lighter.

I'm confused now. In my FED4, that middle window is the lightmeter. Also, from the picture you pointed showing how it works, it looks like the lightmeter. Am I missing something?

 

[Marc Leest]

(i know it's a 35mm camera) ...

thank you

Not always: I have a Fuji GSW690 and thats a 6x9 camera (as I am holding it in my picture)

M.

 

[laz]

A rangefinder is a camera many of my generation abandoned in our youth for the flashy SLR; then in wisdom gained from age, returned to it for the shear pleasure of its use and timelessness of it's design.

I may be primarily a LF kind of guy, but, I'll always keep a rangefinder in my kit!

-Bob

P.S. Does anyone else feel so old after reading the question?

P.P.S Hanaa, no offence intended, I'm so glad you asked and gave the rangefinder folks a chance to discuss their love of what some consider an outmoted technology. I'll go back to LF land now and leave the thread to the experts.

 

[srs5694]

A very good response overall; but....

The adventages of the RF are as follows:
-very quick focusing

On this I must disagree, or at least place conditions. Personally, I find SLRs easier to focus than rangefinders. Rangefinder focus images are ghostlike shadows that I find hard to interpret, and it's easy to get confused when there are multiple lines or a complex shape in that area. With an SLR, getting the main image in the right ballpark is very easy (if it's blurry it's out of focus) and then the split-image or microprism focusing aid can help with getting the focus spot-on.

That said, in low light situations, an SLR's focusing aids degrade more rapidly than do a rangefinder's focusing aids, so a rangefinder can be superior in low-light situations.

All of this interacts with the type of lens, of course. Slow SLR lenses are more likely to cause a black-out of the SLR focusing aids. OTOH, the SLR's focusing ability will be better than a rangefinder's with long lenses at distances that are just a bit shy of infinity -- a typical camera's rangefinder isn't likely to offer enough precision at those distances.

 

[Gordon Coale]

Not only are there many medium format rangefinders, my Mamiya Universal being only one, there are large format rangefinders. They are called press cameras, such as my Speed Graphic with a Kalart rangefinder.

 

[hanaa]

thank you for filling me in. i'm still pretty confused, but i got the idea. i just need to go over what you guys wrote a couple times It sounds really interesting, maybe i'll get my hands on one soon. Of course i'm learning so many things--i should pace myself.

 

[Paul Sorensen]

There are also different categories of rangefinder. The Leica is the best known of the professional or extremely high quality rangefinder cameras but back in the 60s and 70s most camera companies had decent fixed lens rangefinders available. I have a Yashica Electro 35 G that I love. It is certainly in a whole different ballpark than a Leica or Contax, but I got it for about $20 and it is reasonably small and very easy to use. Actually, it is kind of big, but there are no accessories and lenses to worry about. Canon Canonets are more sought after, but still commonly sold for reasonable prices.

Here is a nice site that emphasizes rangefinders: http://www.photoethnography.com/. Forgive them the evil window resize script, they know not what they do!

 

[Andy K]

There is also The Rangefinder Forum. Which is entirely dedicated to rangefinder cameras in all their different guises.

 

[cvik]

rduraoc: The image shows the rangefinder in the Leica M6. It will look different in a Fed 4. For instance the framelines may be painted on the glass and not projected onto it etc.

The Leica M5/M6/M7/MP uses TTL metering. The meter works like this: Light enters through the lens and is reflected by a filled white circle on the shutter curtain. The reflection is read by a sensor pointing towards the circle (see http://www.leica-camera.com/imperia/md/images/leica/geschichte/4_290x292.gif ). It is quite possible the Fed uses a non-TTL meter and that it is placed behind the middle window.

 

[Donald Qualls]

One more kind of rangefinder camera: almost all of the folding, pack-film Polaroids from the 1960s and 1970s had rangefinders, as did most of the better folding roll-film Polaroids in the previous generation. I owned a working one (3x4 prints, Type 47 roll film) in the early 70s, though I only ever managed to buy two rolls of film for it. I own a Model 350 now, waiting for me to get new battery holders wired in to replace the corroded contact ends of the wires; that one takes current film, including Type 665 that will produce a 3x4 format negative.

The other two rangefinder cameras I own are a Moskva-5, 6x9 cm, and a Petri 7S, 35 mm RF.

 

[gnashings]

(if it's blurry it's out of focus) and then the split-image or microprism focusing aid can help with getting the focus spot-on.

Certainly a good point - I just meant that you CAN get it done more quickly, since closest focus to infinity is about a quarter of a turn of the focusing lever... where in an average SLR you sometimes have to turn and turn and turn...
There is no arguing it - an SLR is the more flexible of the two... but who here would give up their RF's?

And guys - I need to point this out - I did mention MF rf's in my original post (I just don't want to come across as giving inaccurate info!)

And... did anyone mention those useless, horrible Canonet QL17 GIII's yet? Horrible little wretched things...

 

[srs5694]

re: Focusing rangefinders vs. SLRs

I just meant that you CAN get it done more quickly, since closest focus to infinity is about a quarter of a turn of the focusing lever... where in an average SLR you sometimes have to turn and turn and turn...

That varies a lot with both types. I just checked a few of my cameras and lenses, and my Canonet QL17 rangefinder does have the shortest throw from closest to farthest focus of those I checked, but the next-shortest was a Zenitar 16mm SLR lens, then a Tamron 24mm SLR lens. The standard 50mm Industar 61L/D lens on a FED 5 rangefinder has roughly a 180-degree turn for full focus range, which is similar to that on my Fujica ST-801 SLR's 55mm standard lens.

The bottom line: If you like lenses with short (or long, for that matter) movement for the full focus range, check the lens; don't assume that you'll get what you want because the camera/lens is of a particular type.

 

[rduraoc]

rduraoc: The image shows the rangefinder in the Leica M6. It will look different in a Fed 4. For instance the framelines may be painted on the glass and not projected onto it etc.

The Leica M5/M6/M7/MP uses TTL metering. The meter works like this: Light enters through the lens and is reflected by a filled white circle on the shutter curtain. The reflection is read by a sensor pointing towards the circle (see http://www.leica-camera.com/imperia/md/images/leica/geschichte/4_290x292.gif ). It is quite possible the Fed uses a non-TTL meter and that it is placed behind the middle window.

Got it. Thank you.

 

[gnashings]

re: Focusing rangefinders vs. SLRs



That varies a lot with both types. I just checked a few of my cameras and lenses, and my Canonet QL17 rangefinder does have the shortest throw from closest to farthest focus of those I checked, but the next-shortest was a Zenitar 16mm SLR lens, then a Tamron 24mm SLR lens. The standard 50mm Industar 61L/D lens on a FED 5 rangefinder has roughly a 180-degree turn for full focus range, which is similar to that on my Fujica ST-801 SLR's 55mm standard lens.

The bottom line: If you like lenses with short (or long, for that matter) movement for the full focus range, check the lens; don't assume that you'll get what you want because the camera/lens is of a particular type.

I am not assuming anything - I just looked at the three rf's I have in the house- a canter beauty, a QL17 and a Bell&Howell Canonet 19. I have handled/shot/played with countless others - but I do not have them on hand. All have close to standard lenses (40mm - 50mm range) and all have no more than a third of a turn "lock to lock" with the QL 17 being about 1/4 of a turn. All the lenses in that focal length range I have (a Nikon, two Canons, one Helios and a Minolta) range from almost a full 360 deg to 3/4 of a turn. I would say its safe to venture a generalization like the one I put forth, since in most cases, it will be true. I never claimed it was a hard and fast rule - but something the average person will find in the average 35mm rf.

edit for ridiculous typos.

 

[srs5694]

Gnashings, it may be true of your three rangefinders, but that's hardly a very wide sample. My (similarly small) sample turned up a much weaker correlation.

 

[gnashings]

I am not trying to be argumentative (I know I come across as such sometimes) - perhaps its the cameras I have nadled, as you say. On the other hand - perhaps this is more correct way to phrase it - while there seems to be some correlation on the higher end, I don't recall anything in SLR lenses taht dos a 1/4 turn, like the QL for example. It was just one of those things that struck me as a user when the RF's where new to me - and I am quite willing to concede that it may be largely a personal reaction based on the cameras I was used to.

Either way, all the best!

Peter.

 

[Woolliscroft]

No one has really answered the question of what are rangefinders good for. Really anything in general photography, other than macro work, where the parallax problem becomes serious. They tend to be quite a bit lighter than SLRs so are easy to carry for long periods, which helps with landscape work and they are less noisy and conspicuous than an SLR which makes them great for candid people shots and street photography. There is no mirror shock, so they are easier to hand hold at low shutter speeds in low light. They can also be easier to focus in low light, although I notice that some people don't agree. Finally, lens designs can be simpler, especially wide angles, as there is no need for retrofocus systems to keep the rear element clear of a moving mirror, so the lenses can be less compromised and so sharper.

David.

 

[Trivette]

I use rangefinders for general photography with focal lengths from 28mm to 90mm. They are particularly useful for short lenses, although accessory viewfinders may be needed. Depending on the camera, lenses longer than about 135mm may not be practical due to focussing difficulties. Most rangefinder enthusiasts use 35mm or 50mm as their normal lens, although 28mm and 40mm are also common. The controls on a typical Leica rangefinder are very similar to those on mechanical SLRs such as the Pentax K1000 or Nikon FM. However, rangefinders have an altogether different "feel" which may be due to the viewfinder. It is like looking through a window directly at the scene, giving a sense of immediacy. There is almost no sense of the camera being a barrier between the photographer and the subject. Some people like this very much (I do); others may find it disconcerting. Unfortunately, on rangefinders without TTL metering, there may be a tendency to take pictures of lens caps.