Optical Viewfinder and Rangefinder Trade-offs

Sonnar Brian

Product of the Fifties
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I doubt that Leica goes through an evaluation of the rangefinder mechanism when going through the initial product design phase for a new camera project. I also doubt most people buying a rangefinder camera go through the process as well. I see many buying new Leica equipment and used rangefinder equipment based on brand and product recognition. Many long-time Rangefinder shooters know and effectively use the advantages of a Rangefinder camera. Recent articles to “time to abandon the Rangefinder” could have been written 60 years ago when SLRs were popular. Here we are in the 2020s and the major manufacturers are ending development of new SLRs and Leica is bringing out new Digital and Film cameras using Rangefinders.

Advantages of Optical Viewfinder/Rangefinder:

You can see things outside the frame. This makes it easier to compose the shot. This also makes it easier to follow a moving subject.

The Viewfinder does not black out when the shutter is released. This makes it easier to make a sequence of shots, For moving subjects, makes it easier to pan and focus.

Optical viewfinders are bright. If there is enough light for your eye to see it, your eye will see about the same level of brightness through the viewfinder. The RF patch is at least as bright.

Lower Latency with all-mechanical shutters. The shutter is closed while viewing and focusing. All-Electronic shutters are also low latency.

No power draw. The viewing and focus mechanism is opto-mechanical and does not require battery power.

No latency when viewing the image. EVF introduces "Digital Delay" between the sensor acquiring the image and the image being displayed. Higher resolution EVF requires a higher data rate and faster processing, which increases power draw.

Disadvantages:

Requires Precise mechanical calibration between the Camera body and the lens. This is expensive to implement. Maintaining precise calibration is difficult.

Not “What you see is what you get”. The photographer’s view is not through the lens.

Precise agreement between the Rangefinder and Lens varies depending on lens aperture and filter used. “Focus shift” due to spherical aberration and chromatic aberration cause disagreement between the rangefinder and lens. Apochromatic and Aspherical lenses that minimize these problems are very expensive. Attempting to correct the issues mechanically would be very complex, and have not been done.

I'll probably add to this list, working on my first cup of coffee as I write this.

Most manufacturers are switching to EVF designs that use the Sensor for viewing. This is a direct replacement for SLR viewfinders. EVF viewfinders with 3.7Mdot range and higher and with focus assist are a direct replacement for SLR viewfinders. The main disadvantage is power draw when compared to an SLR. The "age-old" comparisons made between SLR and RF still hold true comparing EVF and RF.

Maximum "practical" focal length is 135mm.

Requires add-on External Viewfinders for focal lengths longer or shorter than supported by the viewfinder built into the camera.

Requires Eyepiece "Magnifiers" to accurately focus longer focal length lenses from the 85mm range through to the 135mm range used wide-open. Not required when stopped down to F5.6 or so. The same magnifiers are useful for 50mm lenses faster than F1.4 used wide-open.

Maximum Practical minimum focus is about 2feet, 0.7m. "Absolute Kludge" devices allow close-up work.

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ADDED, new section. Thanks to mconnealy

Problems to look for when buying Used that apply to Rangefinder Cameras.

Deteriorated silver/gold in the prisms and beamsplitters.

Cement Separation in the prisms and viewfinder optics.

Mechanically worn down parts that prevent proper calibration of the RF.

Shifting of the prisms and beamsplitters, causing problems in the RF image. Contax is infamous for this.

Gummed up or weak Return Springs for the RF Cam Follower and Frameline Selection, usually fixed with a CLA

MYSELF: I have seen every one of these problems, mostly in cameras 50+ years old.
 
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This is an age old discussion as you mentioned. I enjoy using rangefinders more but always have doubts concerning the accuracy of the viewfinder.

I feel more comfortable using a SLR - particularly the Nikon F2 with its 100% accurate viewfinder.
 
I've used the Nikon F2a since 1978, and is my favorite film SLR. I picked up the F3HP, just prefer the F2.
I've used RF's since 1969 and SLR's since 1971. These days- The Nikon Df, and Leica M9 are the favorites.
 
I tend to frame a shot before the camera is raised and pointed. This usually involves being aware of the context (the peripheral view) of the shot so anything that helps retain that relationship between framing and the broader area is a plus. Using a zoom lens on a TTL camera sometimes helps, but the view through a SLR limits one to what is seen in that tunnel. Workable but hardly ideal. For me, the viewfinder is there simply to check the framing I have already chosen. Over the years I've found that optical viewfinders let me judge how I want to frame and set the exposure efficiently and quickly, rather than trying to figure out how to translate what an electronic simulation provides. I do use digital viewfinders, they can get the job done, but I trust my instincts more, which the optical viewfinder doesn't get in the way of.
 
I started photography with an SLR and I still prefer an OVF made from prism and reflex mirror. But I was also happy with the RFs I've used. Just looking at the world with a frame around it is kinda nice. Today, the closest I'm coming to a RF is using the Fuji X-Pro in OVF mode. It's good as well. I've yet to come to happy terms with EVFs but I use them, mostly begrudgingly.
 
I used cameras for the enjoyment up until about 1967 when I also started using them for work. I had my father's Welti non-rangefinder, and sometimes a Minolta 16. Don't sound much like crime scene cameras, but the US Army where I was didn't provide anything. I got my first SLR which was a Yashica TL Super with a 50mm lens. I had decided I needed one of those pro-type cameras since my Welti was scratching film and I didn't know how I might fix it.. Actually, having bought it with cost most in mind, it was a good, rugged camera, and the Yashinon lens was better than I expected. In the mid-70s, I really got in to photography. I started buying lenses (figured out why a camera should have interchangeable lenses ???) When my Yashica 6x6 was stolen, I got a rangefinder, the Mamiya Press camera with 6x7 back. I just accepted it had a rangefinder, and used it when I wanted a bigger negative, and my SLR for everything else (by then I also had a Fukica ST 901. What a great camera).

I just never sweated over whether SLR or rangefinder was better. Of the cameras I had, I just learned to use them for whatever kind of photo I wanted to take. I just never understood that one should be better than the other. I cannot really understand this type of discussion, except for user preference, which is OK for anyone to have.

And I am speaking of the past, since even before Covid, my photo taking had just about gone away due to health reasons. If I could get back in to it though, I would still use what I thought was going to give me the photo I wanted, SLR or RF,wouldn't make a difference. Sound weird? More weird, I enjoy reading threads like this, for whatever I might learn or understand better.

EDIT: Hey dogman, I see we look at things (no pun intended) very nearly the same.
 
Under "Disadvantages" I would add the inevitable fading of contrast in the rf window in even the best cameras along with the repair costs. Some of my old slr cameras like the Retina Reflex have deteriorated prisms and mirrors, but most still show a fine view decades after manufacture.
 
Under "Disadvantages" I would add the inevitable fading of contrast in the rf window in even the best cameras along with the repair costs. Some of my old slr cameras like the Retina Reflex have deteriorated prisms and mirrors, but most still show a fine view decades after manufacture.

I added a new section for Rangefinder specific issues for people looking to buy cameras. I will list more as they come back to me. Listed the ones above from personal experience taking cameras apart to fix them, or have repaired.

Definitely something to look for when considering an older/ used Film camera. Always have return privilege, unless dirt-cheap with a repair factored in. I have a Nikon S2 and a Nikon S4 with that problem, 2 in 14 of my Nikon RF's. On the two with desllvered RF prisms: I removed the mask behind the RF windows. This results in a bigger patch, the prism behind the mask was in better shape than the exposed portion.

The two SP rangefinder spots are as good as an SP-2005 that I handled when it came out. Same with the original S3- as good as my S3-2000. With the Contax II, III, IIa, and IIIa- more of a problem with the cement in the main viewfinder. Canon 7, Canon P, Canon V-T, Canon IIIa, and Canon III: cleaned haze out of the viewfinder. These cameras are 60+ years old, so a must check for buying used cameras. I had Youxin Ye replace the beamsplitter on my Leica IIIa and Leotax D-IV. Not a significant cost when being done as part of the CLA.

Buying a Digital Rangefinder: The Electronics are going to fail long before the optical portions of the VF/RF. Basic capacitors and voltage convertors will fail, as will the digital sensor itself.

Kodak Retina Reflex-S: I replaced the badly desilvered prism with one from a much newer Minolta XG-1. Perfect fit, much brighter than the original prisms in the Retina series. The prisms in the Nikon F finders - I have a couple with ugly spots mostly at the seam.
 
Fabulous post Brian!
Love the Pro-Con list.
Great dir anyone considering RF.

Yet, for my it was different. I really liked my old Summaron, Summicron and 90 Elmar. Small, light and good performance. When the 240 full frame came out I actually had no choice/excuse.
Now I’m travelling with my Typ262 M-D and get a dopamine rush every time I lift it to my eye. It just feels so right. I never think of Pro-Con. I rarely take more than one image, kind of like when travelling with limited film in the past. I like to compose before taking an image, I don’t crop or process except for minor exposure adjustments. The other day I was in Varosha in Cyprus and when I posted those photos on the website thought ‚yay - feels right, the RF is easy and suits me.‘
 
The way Nikon’s SP employs multiple framelines in a “tunnel”-like effect as you select longer focal lengths is interesting and clever, albeit cluttered.

One nice thing Fuji’s X-Pro cameras do with the optical viewfinder is adjust what you see based on focal length (at least that’s true for my 35mm and 23mm lenses).

What would be interesting and innovative for Leica (although complex and expensive) is to eliminate the confusing pairs of frame lines and devise an optical viewfinder which would have just a single set of frame lines appropriate to the focal length (while still letting you see beyond the frame lines). As you change to different focal length lenses, the view through the finder and the frame lines adjust accordingly. Much easier said than done, I’m sure. Is it possible? I don’t know.
 
When the X100 was first out, I wrote that it could be used to do just that- put up a single frameline at a time, matching focal length, Parallax, and Field of view with distance. That would not be hard. You would need a "Shaft Encoder" for the RF arm to digitize the distance to a small microcontroller, use that to generate the framelines of the Hybrid finder.
 
Perhaps an undervalued point that has been overlooked since the industry move to mirrorless is the viewing experience, and the optical viewfinder is the most direct viewing experience to reality than having to see through what the camera only is capable of seeing.Beside Leica & Pixii, Pentax DSLR and Fuji hybrids are currently the only companies to my knowledge that offer such a experience. This era has been swept up by digital screen addiction and I don't want to be forever looking through a digital screen in my photography
 
The way Nikon’s SP employs multiple framelines in a “tunnel”-like effect as you select longer focal lengths is interesting and clever, albeit cluttered.

One nice thing Fuji’s X-Pro cameras do with the optical viewfinder is adjust what you see based on focal length (at least that’s true for my 35mm and 23mm lenses).

What would be interesting and innovative for Leica (although complex and expensive) is to eliminate the confusing pairs of frame lines and devise an optical viewfinder which would have just a single set of frame lines appropriate to the focal length (while still letting you see beyond the frame lines). As you change to different focal length lenses, the view through the finder and the frame lines adjust accordingly. Much easier said than done, I’m sure. Is it possible? I don’t know.

The Contax G cameras did that, albeit without framelines. It even worked with their 35-70 zoom! The view did not include anything outside the frame, however.
There were some complaints that the viewfinder was small and gave "tunnel vision". I will grant that it wasn't anywhere near that of an M3, but I found it more than adequate. Overall, those cameras were works of engineering genius, and sadly missed.
 
Dante Stella wrote an article on the advantages, both real and alleged, of rangefinders over SLRs:
https://www.dantestella.com/technical/rangefinder.html
This is one that speaks to me, despite never having shot with a Sonnar lens of any kind:
Lenses with well-defined optical fingerprints. These are the 50mm Sonnar-type lenses which could never be made for an SLR due to back-focus constraints. All modern SLR 50mm lenses are planar-type. With a lot of modern lenses you lose bokeh and highlight separation.
 
I bought Dante's late Black 13.5cm F3.5 Nikkor from him. Perfect glass. I use a 1.25x finder for it on the M9. No problem focusing with it. Same is true with the 7artisans 75mm F1.25. I've gotten pretty good at shooting moving skaters under low-light, using the 1.25x finder. I am going to add that to the first post.

Required external viewfinders to extend focal length past that supported by the viewfinder, and use of a magnifier for long-focal length lenses and super-speed lenses used wide-open.
 
"Maximum Practical minimum focus is about 2feet, 0.7m. "Absolute Kludge" devices allow close-up work. Best left to a Masochist to use them or a collector to display one."

Is what I wanted to add, but left off the last part. I bought a close-up set for the Nikon SP, was going to rip it apart and make a frameline illuminator out of the Holder for the close-up lens for the viewfinder, which mounted in the accessory shoe. Did not have the heart to do it, was too nicely made.
 
Dante Stella wrote an article on the advantages, both real and alleged, of rangefinders over SLRs:
https://www.dantestella.com/technical/rangefinder.html
This is one that speaks to me, despite never having shot with a Sonnar lens of any kind:
Lenses with well-defined optical fingerprints. These are the 50mm Sonnar-type lenses which could never be made for an SLR due to back-focus constraints. All modern SLR 50mm lenses are planar-type. With a lot of modern lenses you lose bokeh and highlight separation.

Sonnar formula lenses can be used with mirrorless cameras without problem. 50mm and 85mm Sonnar formula lenses cannot be used, on the Nikon F-Mount- the shortest Nikkor of the Sonnar type is the 10.5cm F2.5. None were ever made in Ai mount, but can be used with the Nikon Df "uncoupled" mode. If you want to shoot an Aperture-preferred film camera that takes most every manual focus Nikon SLR lens made, get a Nikkormat EL or ELw. These have aperture-preferred autoexposure. The Nikon F2Sb and F2S offer shutter-preferred autoexposure with almost every manual focus F-Mount lens using the DS-1 and DS-2 Servo-Motor. They work. Leave those to the collectors.

https://www.ebay.com/itm/304627556282

Must be a collector. Or someone dropped on their head as a baby. I made custom batteries for mine, just to watch it work.
 
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