jagarch
Member
Leaving aside all practical matters like profit, ease of manufacturing, etc.
I have an idea for a device that could turn a scale focus camera into a rangefinder. It seems so simple that I'm sure folks have thought it up before, and maybe even attempted it, but i couldn't find any info on this forum. Maybe I'm looking up the wrong terms?
When you use an old camera with an accessory rangefinder, you focus the rangefinder. Then you translate the distance reading on the rangefinder to the distance scale on the lens. But couldn't you couple the distance readings together, mechanically?
The idea is this: take an old accessory rangefinder, like the Widor or the Voigtlander. These are shoe-mounted, and have a little wheel which you turn to find the focus. Mechanically connect this wheel to a lens, so that focusing the lens turns the wheel.
Obviously every lens is different. Even if you could make this work for only one lens, say a standard prime, this would be a very powerful tool. You could mount it on a EP-1 and make it into an actual digital rangefinder camera, for a fraction of the price of an M8.
Even better would be if you could find a way so that the mechanical coupling could be calibrated for any lens. You put the lens at infinity, calibrate the coupling, and then put the lens at its closest range and calibrate that.
If this was manufactured rather than cobbled together from existing parts, the rangefinder could include a viewfinder, and the whole thing, including lens, could be one unit.
I greatly simplified the mechanics in this mock-up, but is this possible?
I have an idea for a device that could turn a scale focus camera into a rangefinder. It seems so simple that I'm sure folks have thought it up before, and maybe even attempted it, but i couldn't find any info on this forum. Maybe I'm looking up the wrong terms?
When you use an old camera with an accessory rangefinder, you focus the rangefinder. Then you translate the distance reading on the rangefinder to the distance scale on the lens. But couldn't you couple the distance readings together, mechanically?
The idea is this: take an old accessory rangefinder, like the Widor or the Voigtlander. These are shoe-mounted, and have a little wheel which you turn to find the focus. Mechanically connect this wheel to a lens, so that focusing the lens turns the wheel.
Obviously every lens is different. Even if you could make this work for only one lens, say a standard prime, this would be a very powerful tool. You could mount it on a EP-1 and make it into an actual digital rangefinder camera, for a fraction of the price of an M8.
Even better would be if you could find a way so that the mechanical coupling could be calibrated for any lens. You put the lens at infinity, calibrate the coupling, and then put the lens at its closest range and calibrate that.
If this was manufactured rather than cobbled together from existing parts, the rangefinder could include a viewfinder, and the whole thing, including lens, could be one unit.
I greatly simplified the mechanics in this mock-up, but is this possible?
Attachments
archive59
Established
Robot manufactured a rangefinder attachment for their Robot II and IIa models that used a very similar concept to the one you are proposing.
See near the bottom of this page for photos
http://www.robot-camera.de/ROBOT_Kameras/Robot_II/Robot_IIa/robot_iia.html
The idea falls somewhat short in reality though. The Robot version allows for 3 different focal length lens (and their different physical size) but Robot lens have the advantage of a distinct ridge around the lens on which the lever can rest but you still need to recalibrate every time. The whole structure is 'out in the open' and very vulnerable. The example I have, which is admittedly 60 odd years old, has so much play in everything as to make it pretty much useless.
I think you will have your work cut out in creating your rangefinder if you want it to be universal and/or properly usable.
But best of luck!
See near the bottom of this page for photos
http://www.robot-camera.de/ROBOT_Kameras/Robot_II/Robot_IIa/robot_iia.html
The idea falls somewhat short in reality though. The Robot version allows for 3 different focal length lens (and their different physical size) but Robot lens have the advantage of a distinct ridge around the lens on which the lever can rest but you still need to recalibrate every time. The whole structure is 'out in the open' and very vulnerable. The example I have, which is admittedly 60 odd years old, has so much play in everything as to make it pretty much useless.
I think you will have your work cut out in creating your rangefinder if you want it to be universal and/or properly usable.
But best of luck!
xxloverxx
Shoot.
Possible, certainly, but:
The focus throw of the RF wheel and the lens wheel would have to be the same; even slightly different and you'd have to use gears (or something similar) to adjust the amount of effect given to the lens when turning the RF wheel (am I making sense?)
To control a lens' focus wheel via external RF wheel would be no easy task on the fingers
How would you link the two? Cables? Clunky gears like…was it the Argus C3 and the old Kodaks? How reliable would that be?
How would you lock the focusing mechanism onto the lens? Most lenses (except for those like the Jupiter 8) would be very hard to get a reliable grip on with a gear.
Each lens' focusing wheel is at a different position and of different size and/or shape.
How would you focus the external RF quickly without risking poking yourself in the face (possibly in the eye)?
It's a great concept; certainly unique and, at least for me, unheard of until I read this post. But there are a few problems that need to be sorted out…but once those get sorted out, we can make any camera into a rangefinder.
The focus throw of the RF wheel and the lens wheel would have to be the same; even slightly different and you'd have to use gears (or something similar) to adjust the amount of effect given to the lens when turning the RF wheel (am I making sense?)
To control a lens' focus wheel via external RF wheel would be no easy task on the fingers
How would you link the two? Cables? Clunky gears like…was it the Argus C3 and the old Kodaks? How reliable would that be?
How would you lock the focusing mechanism onto the lens? Most lenses (except for those like the Jupiter 8) would be very hard to get a reliable grip on with a gear.
Each lens' focusing wheel is at a different position and of different size and/or shape.
How would you focus the external RF quickly without risking poking yourself in the face (possibly in the eye)?
It's a great concept; certainly unique and, at least for me, unheard of until I read this post. But there are a few problems that need to be sorted out…but once those get sorted out, we can make any camera into a rangefinder.
Dave Wilkinson
Veteran
mmmm.....now where can I find a gear-train to connect these two? 
Dave
Dave
Mark Wood
Well-known
Isn't this rather like the connection that Argus used for connecting the rangefinder to the lens on the C3 "brick"?
FallisPhoto
Veteran
Well, I see a number of problems. The adjustment wheel on the rangefinder would have to be the exact size to accurately focus the lens, and it would be different for every camera. That big right-angle linkage would have enough stress on it that it would need to be made of carbon fiber or something stronger in order not to deform. You need to eliminate the right angle. The shortest distance between two points is a straight line, and a straight linkage will apply less sideways pressure and will be less likely to deform, so I'd make it as straight as possible. Also, some of your photos/drawings didn't come up. Lenses don't just push in and out, they screw in and out, so I assume you have a ring of some kind attached to the front of that linkage? How would you attach the linkage to it without blocking the lens? With that attached to the front of the lens, how would you screw the lens in and out? Also, the accessory rangefinder couldn't be a shoe mount anymore, because the foreward/backward pressure of the lens adjustment would just push/pull it out of the shoe.
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jagarch
Member
Yeah, these are the problems.
Hmmm
Yes, you would near gears to adjust the ratios.
How about focusing with the lens, and using it to drive the rangefinder motion, rather than the other way around?
To attach to the lens, maybe some sort of clamp or strap that could be tightened?
Maybe this would only work with a lens that had a focusing tab? And you could attach the contraption to the tab? or take a tabless lens and add a tab to it?
Maybe this would only be possible on a lens made just for this purpose?
Micro 4/3's lens with attached optical rangefinder device?
batterytypehah!
Lord of the Dings
I think the biggest hurdle is making this one contraption work on a variety of cameras and lenses.
For just one camera and lens, this has indeed been done. Kodak took the 35 and turned it into the 35 RF by adding an afterthought RF. By all accounts it worked well. It also looked awful and cost way more than the Argus that it was supposed to compete with.
For just one camera and lens, this has indeed been done. Kodak took the 35 and turned it into the 35 RF by adding an afterthought RF. By all accounts it worked well. It also looked awful and cost way more than the Argus that it was supposed to compete with.
RichC
Well-known
Been done.
I recall a really old (1930s, 1940s?) issue of the UK's "Amateur Photographer" magazine showed a scale-focus camera that some DIY enthusiast had made a coupled rangefinder for. It used wooden cogs, I think - very Heath Robinson!
I recall a really old (1930s, 1940s?) issue of the UK's "Amateur Photographer" magazine showed a scale-focus camera that some DIY enthusiast had made a coupled rangefinder for. It used wooden cogs, I think - very Heath Robinson!
Dave Wilkinson
Veteran
O.K. -let's dream a little more, the focus helicoid in a lens is no more than a multi-start thread - some may be 'four start', some five or three etc., affecting the speed it moves in and out - the 'throw' of the lens from close to infinity. Each one would need a connection (gears ?) to move the rangefinder in correct synchronisation to achieve focus, and as in gear wheels that I have cut for clock mechanisms - a tooth too many or too few, and the thing aint accurate! - so perhaps you had better think about rod coupling, just don't have any 'play' in 'em, ( like you would inevitably have in gears! ) or you are stuffed again!
Dave.
Dave.
rbiemer
Unabashed Amateur
http://www.flickriver.com/photos/nesster/4315862834/
There were other versions of this as well. I think they were generally made for specific camera lens combinations and so not universal.
Rob
There were other versions of this as well. I think they were generally made for specific camera lens combinations and so not universal.
Rob
radi(c)al_cam
Well-known
Yes, an intriguing idea!
On http://vintagephoto.photobutmore.de/photokram/ Mr Neuhaus shows the RoBoT contraption. Quite nice.
BTW, you mix in the best society:
with her "Flexameter" Ms Elsie Leitz-Kühn PhD was on the same way.
On http://vintagephoto.photobutmore.de/photokram/ Mr Neuhaus shows the RoBoT contraption. Quite nice.
BTW, you mix in the best society:
with her "Flexameter" Ms Elsie Leitz-Kühn PhD was on the same way.
johannielscom
Snorting silver salts
radi(c)al_cam
Well-known
radi(c)al_cam
Well-known
radi(c)al_cam
Well-known
look, at least one RFF member does even USE his Megoflex http://www.rangefinderforum.com/forums/showthread.php?t=74268&highlight=megoflex