Hcompton79
Established
If you know vintage Kodaks, you probably are aware of this camera. It's the Kodak Ektra, Kodak's 1941 attempt to produce the worlds finest 35mm interchangeable lens rangefinder camera, beating out contemporary Leica and Contax cameras.
Being a Kodak collector, this is one of the cameras I have lusted over for the longest time. It's the one of the finest cameras to ever come out of Rochester and the finest American rangefinder ever made, but with only 2000 made, they command ridiculous money in the market.
After a few years of watching various action sites, I finally came across one that didn't cost me an arm and leg. It's got some problems, the shutter is jammed (quite typical) but the curtains and their straps appear to be in good shape. I also need to locate the auxiliary 35mm finder window for this lens or a 50mm Ektar lens to go with it.
Attachments
Larry Cloetta
Veteran
Let us know what the real world experience turns out to be. I’d be curious, as I doubt I will ever own one.
someonenameddavid
Well-known
Let me know if you find a service person to fix it: my shutter is jammed too
Hcompton79
Established
If you haven't seen it, I would suggest reading Mike Eckman's review on it. He probably does a better justice to this camera than I ever could, but I will definitely post my thoughts on it and sample photos when possible.
https://www.mikeeckman.com/2019/07/kodak-ektra-1941/
https://www.mikeeckman.com/2019/07/kodak-ektra-1941/
Hcompton79
Established
I'll be servicing it myself. I do all my own CLAs. I've never worked on an Ektra, but I also never worked on a Retina Reflex, Medalist or Synchro-Rapid 800 before I tackled all of those.
Hcompton79
Established
Continuing to post a couple photos of the Ektra's internals, as I don't think there are any elsewhere on the internet and I want to have some archived in the event another brave soul endeavors to take theirs apart.
The Ektra shutter is normally referenced as being unique, but normally the commentary ends there. Sometimes it is mentioned that it runs left to right and that the gap is preset before the shutter fires. Other notable features I have discovered are that the gap between shutter curtains is not fixed, but actually on a geared reduction that changes the gap between the curtains as they traverse the film gate with the gap growing slightly wider as the shutter accelerates. This means the exposure is more even as the gap is widest as the shutter is moving fastest and vice versa. The gear train retard systems for the slow speeds and self timer appear to be very similar in design or adaptations of those same systems on a Supermatic shutter.
I got the shutter unjammed, and the curtains are in good shape with no broken ribbons or pinholes. I'm guessing it jammed when someone tried to change the shutter speed without the shutter being cocked. The curtains appear to be rubberized nylon, but they may also be silk, I'm not an expert on material science. It's working fine from 1/25 to 1/1000, but the slow speed escapement and self timer are gummed up with old lubricant and will need to be cleaned out.
Overall, very unique and mechanically intricate design. I can see why it has a reputation for being difficult to service, but in reality it's different not difficult.
The Ektra shutter is normally referenced as being unique, but normally the commentary ends there. Sometimes it is mentioned that it runs left to right and that the gap is preset before the shutter fires. Other notable features I have discovered are that the gap between shutter curtains is not fixed, but actually on a geared reduction that changes the gap between the curtains as they traverse the film gate with the gap growing slightly wider as the shutter accelerates. This means the exposure is more even as the gap is widest as the shutter is moving fastest and vice versa. The gear train retard systems for the slow speeds and self timer appear to be very similar in design or adaptations of those same systems on a Supermatic shutter.
I got the shutter unjammed, and the curtains are in good shape with no broken ribbons or pinholes. I'm guessing it jammed when someone tried to change the shutter speed without the shutter being cocked. The curtains appear to be rubberized nylon, but they may also be silk, I'm not an expert on material science. It's working fine from 1/25 to 1/1000, but the slow speed escapement and self timer are gummed up with old lubricant and will need to be cleaned out.
Overall, very unique and mechanically intricate design. I can see why it has a reputation for being difficult to service, but in reality it's different not difficult.
Hcompton79
Established
I've been working more on the Ektra when time permits. I already have it together and have shot a couple of test rolls through it (soon to come) but this is a recap of the repair and refurbishment. Fortunately, the 1943 Ektra repair manual is available though Pacific Rim: (warning - 500MB dowload)
https://www.pacificrimcamera.com/rl/01346/01346.pdf
Cleaning the optics and aligning the rangefinder were fairly uneventful other then being tedious. I disassembled the lens to clean the old grease off the helical and re-lubricate. It's much smoother now and collimating the focus with the body was quite easy.
The optics in the top cover were also cleaned, this was somewhat tiring as the Ektra has five glass optical lenses which make up the variofocal viewfinder and the rangefinder has five prisms and six lenses and my ADHD won't let me leave a single speck of dust visible in any of them. adjusting the rangefinder is easy with one screw doing halving and another doing the horizontal alignment.
The tricky part has been the Ektra's shutter, mainly understanding the mechanism, since it is similar in some ways to other shutters but it has key differences. I am not aware of any other resource for understanding the shutter either, so other than the above repair manual (which is largely text based and has few diagrams) I am flying into uncharted territory.
What we know is that the Ektra uses a three drum shutter, much like a Leica, but differs mainly from a Leica shutter in setting the gap between the curtains. On the Leica, the gap is made by delaying the release of the trailing curtain. On the Ektra, the gap is made on the curtain drum before any curtains release.
So on the Leica, the chain of events is that the shutter is wound with the curtains overlapping, then they stop. The leading curtain is released, then there is a delay and the second curtain is released creating the gap where they both run to the resting position. In this design each curtain is tensioned separately and the tension on each curtain determines the curtain velocity.
On the Ektra, there is a gap between the curtains as they rest. When winding begins, the leading curtain needs to pick up immediately and close the gap with the trailing curtain so that the film in the film plane is not exposed as the shutter is wound. Once the leading curtain clears the film aperture the leading curtain stops moving. The trailing curtain continues to move and wind around the center of the curtain drum setting the gap. The gap is 0.030" at 1/1000 and about 1.375" at 1/25. The shutter is thus wound and the sear catch releases both curtains simultaneously, running back onto their rollers. In this design, each curtain roller can be tensioned, but the roller drum rigidly couples the two curtains and the differing inner and outer diameters of the drum regulate the curtains so that the gap starts out narrow and widens as the curtains accelerate to give an even exposure.
The Extra's operation necessitates a complex shutter drum, and this is evident in the following diagram. The center portion which holds the narrow trailing curtain is rigidly coupled to the winding mechanism and speed throw-out. The upper roller for the wide leading curtain is coupled to the center portion of the drum and thus the winding mechanism by two different mechanisms simultaneously, there's a backlash spring on the center spindle which allows the wide curtain to stop and the narrow curtain to continue to wind, but not change the spacing when released. There is also a toothed gear and pawl which limits rotation in one direction only until the drum rotates and centrifugal force pushes the pawl outwards which allows the gap to change once the leading curtain is fully on it's roller, closing the gap and allowing the shutter to blackout when rewound. The lower roller for the wide leading curtain is coupled to the center drum by means of a spring which allows the roller to rotate independently but under spring tension.
The manual indicates the Ektra shutter went though at least one revision, as it lists a "early" and "late" version when it was published in 1943 with the changes being how the lower roller is coupled to the drum and the late version having an additional ribbon roller. FWIW, my camera is SN 3724 and has an early style shutter. Serial numbers are reported to have started at 1000 and production was estimated at 2000 to 2400 examples. Make of that what you will.
Understanding the operation of the shutter I still had to take it apart to clean the bearings and thus remove the curtains to do so. Lots more intricate work. Cleaning the bearings necessitated removing tension of the rollers, so I notated the number of turns on each roller for later, but preliminary settings are also listed in the repair manual.
With the shutter cleaned and reassembled the next question was calibration. The repair manual lists tolerances for each shutter speed, but with both roller tensions, the curtain slit width and the speed control throw-out all having control over the shutter speed and being interactive controls, the need to measure the effective shutter speed and its evenness is imperative.
Kodak referenced the "Ektra shutter speed tester" in the repair manual. I have little other details on it, but the tolerance list would suggest that it output a singular or average shutter speed in milliseconds, and I believe it to be the apparatus shown below:
I don't have such an apparatus at my disposal, and likely none exist at this point in time. In the past, I have used a photo-diode and bright light to output a signal to a program like Audacity to measure shutter speed. This is fine for a leaf shutter, but a focal plane shutter requires at least two measurements to ensure that the shutter is traveling evenly over the film plane. Some modern focal plane shutter testers use 3 to 5 sensors, but professional models like those made by Kyoritsu can cost hundreds to thousands of dollars.
With that in mind, I built my own shutter tester to test the Ektra's shutter speeds. It uses lasers and two photo-transistors biased as photo-diodes. The sensors are mounted about 30MM apart giving an effective speed based on gap width and velocity at the start and end of the shutter's travel. The key attribute is that each sensor is under an aperture of only 0.030" which is the narrowest gap of the shutter, which gives a point estimation of shutter speed. The signals are output though a stereo connector to my computer running Audacity which allows me to compare the signals and given the specs of my sound card, This allows me to resolve the shutter speed down to 0.1 ms with an accuracy of +/- 0.02 ms (1/1000 is 1 ms).
With this in hand, I've been able to calibrate the Ektra's shutter to its original tolerances and reassemble the camera. I've already shot some test rolls, including a roll of Provia 100F to confirm even shutter travel and will develop and scan tomorrow.
https://www.pacificrimcamera.com/rl/01346/01346.pdf
Cleaning the optics and aligning the rangefinder were fairly uneventful other then being tedious. I disassembled the lens to clean the old grease off the helical and re-lubricate. It's much smoother now and collimating the focus with the body was quite easy.
The optics in the top cover were also cleaned, this was somewhat tiring as the Ektra has five glass optical lenses which make up the variofocal viewfinder and the rangefinder has five prisms and six lenses and my ADHD won't let me leave a single speck of dust visible in any of them. adjusting the rangefinder is easy with one screw doing halving and another doing the horizontal alignment.
The tricky part has been the Ektra's shutter, mainly understanding the mechanism, since it is similar in some ways to other shutters but it has key differences. I am not aware of any other resource for understanding the shutter either, so other than the above repair manual (which is largely text based and has few diagrams) I am flying into uncharted territory.
What we know is that the Ektra uses a three drum shutter, much like a Leica, but differs mainly from a Leica shutter in setting the gap between the curtains. On the Leica, the gap is made by delaying the release of the trailing curtain. On the Ektra, the gap is made on the curtain drum before any curtains release.
So on the Leica, the chain of events is that the shutter is wound with the curtains overlapping, then they stop. The leading curtain is released, then there is a delay and the second curtain is released creating the gap where they both run to the resting position. In this design each curtain is tensioned separately and the tension on each curtain determines the curtain velocity.
On the Ektra, there is a gap between the curtains as they rest. When winding begins, the leading curtain needs to pick up immediately and close the gap with the trailing curtain so that the film in the film plane is not exposed as the shutter is wound. Once the leading curtain clears the film aperture the leading curtain stops moving. The trailing curtain continues to move and wind around the center of the curtain drum setting the gap. The gap is 0.030" at 1/1000 and about 1.375" at 1/25. The shutter is thus wound and the sear catch releases both curtains simultaneously, running back onto their rollers. In this design, each curtain roller can be tensioned, but the roller drum rigidly couples the two curtains and the differing inner and outer diameters of the drum regulate the curtains so that the gap starts out narrow and widens as the curtains accelerate to give an even exposure.
The Extra's operation necessitates a complex shutter drum, and this is evident in the following diagram. The center portion which holds the narrow trailing curtain is rigidly coupled to the winding mechanism and speed throw-out. The upper roller for the wide leading curtain is coupled to the center portion of the drum and thus the winding mechanism by two different mechanisms simultaneously, there's a backlash spring on the center spindle which allows the wide curtain to stop and the narrow curtain to continue to wind, but not change the spacing when released. There is also a toothed gear and pawl which limits rotation in one direction only until the drum rotates and centrifugal force pushes the pawl outwards which allows the gap to change once the leading curtain is fully on it's roller, closing the gap and allowing the shutter to blackout when rewound. The lower roller for the wide leading curtain is coupled to the center drum by means of a spring which allows the roller to rotate independently but under spring tension.
The manual indicates the Ektra shutter went though at least one revision, as it lists a "early" and "late" version when it was published in 1943 with the changes being how the lower roller is coupled to the drum and the late version having an additional ribbon roller. FWIW, my camera is SN 3724 and has an early style shutter. Serial numbers are reported to have started at 1000 and production was estimated at 2000 to 2400 examples. Make of that what you will.
Understanding the operation of the shutter I still had to take it apart to clean the bearings and thus remove the curtains to do so. Lots more intricate work. Cleaning the bearings necessitated removing tension of the rollers, so I notated the number of turns on each roller for later, but preliminary settings are also listed in the repair manual.
With the shutter cleaned and reassembled the next question was calibration. The repair manual lists tolerances for each shutter speed, but with both roller tensions, the curtain slit width and the speed control throw-out all having control over the shutter speed and being interactive controls, the need to measure the effective shutter speed and its evenness is imperative.
Kodak referenced the "Ektra shutter speed tester" in the repair manual. I have little other details on it, but the tolerance list would suggest that it output a singular or average shutter speed in milliseconds, and I believe it to be the apparatus shown below:
I don't have such an apparatus at my disposal, and likely none exist at this point in time. In the past, I have used a photo-diode and bright light to output a signal to a program like Audacity to measure shutter speed. This is fine for a leaf shutter, but a focal plane shutter requires at least two measurements to ensure that the shutter is traveling evenly over the film plane. Some modern focal plane shutter testers use 3 to 5 sensors, but professional models like those made by Kyoritsu can cost hundreds to thousands of dollars.
With that in mind, I built my own shutter tester to test the Ektra's shutter speeds. It uses lasers and two photo-transistors biased as photo-diodes. The sensors are mounted about 30MM apart giving an effective speed based on gap width and velocity at the start and end of the shutter's travel. The key attribute is that each sensor is under an aperture of only 0.030" which is the narrowest gap of the shutter, which gives a point estimation of shutter speed. The signals are output though a stereo connector to my computer running Audacity which allows me to compare the signals and given the specs of my sound card, This allows me to resolve the shutter speed down to 0.1 ms with an accuracy of +/- 0.02 ms (1/1000 is 1 ms).
With this in hand, I've been able to calibrate the Ektra's shutter to its original tolerances and reassemble the camera. I've already shot some test rolls, including a roll of Provia 100F to confirm even shutter travel and will develop and scan tomorrow.
Larry Cloetta
Veteran
Looking forward to the photos. Thanks for posting.
Pál_K
Cameras. I has it.
I’m curious why Kodak chose to have a mechanism where the gap is set prior to release. Better long term accuracy? Easier to adjust over the life of the camera? Perhaps it just seemed to be the “proper” way in their quest for an excellent design.
Although the execution is vastly different, using the mechanism to pre-set the slits is something the Ektra has in common with the pre-war Contaxes. Using gearing to compensate for curtain acceleration is fascinating, never seen that before. Would love to see some images of the rangefinder system too, if you happen to have any. Great work. Well done.
Hcompton79
Established
Here's a couple of screenshots from the Ektra repair manual and promotional brochure showing the rangefinder and viewfinder mechanism and an overhead diagram of the rangefinder:
raydm6
Yay! Cameras! 🙈🙉🙊┌( ಠ_ಠ)┘ [◉"]
Excellent work! Love seeing the inside of this camera. Thanks for sharing!
Adnei M A
Newbie
Dear Hcompton79, I am delighted with your post about your EKTRA! So many precious informations about this wonderful Kodak camera.
I am a long time collector of rangefinder cameras, living in Sao Paulo, Brazil. For a long time I searched for an EKTRA. I finally found one, which is well preserved, with two backs and the original KODAK single camera case. Its shutter is jammed, but worst is it lacks the speed selector knob. I searched a lot for one without success. Perhaps I should try to have a experient mechanician making one for me. A big problem is that I did not find drawings of such knob. Among your posted photos there is one which shows some details of the knob, the two hollowed screw. I wonder if you could help with a picture showing the interior of the knob, or its dimensions, or if between the knob and its fixing screw there is a coiled spring. Any help will be precious!
I am a long time collector of rangefinder cameras, living in Sao Paulo, Brazil. For a long time I searched for an EKTRA. I finally found one, which is well preserved, with two backs and the original KODAK single camera case. Its shutter is jammed, but worst is it lacks the speed selector knob. I searched a lot for one without success. Perhaps I should try to have a experient mechanician making one for me. A big problem is that I did not find drawings of such knob. Among your posted photos there is one which shows some details of the knob, the two hollowed screw. I wonder if you could help with a picture showing the interior of the knob, or its dimensions, or if between the knob and its fixing screw there is a coiled spring. Any help will be precious!
Attachments
Hcompton79
Established
Hi Adnei,
My apologies for the delayed response. Since the forum changeover, it appears I am no longer receiving post reply notifications.
I took apart my speed setting knob and took dimensions for you, hopefully you find this helpful. I do believe it would be a very difficult task to replicate these components, as the machining operations are very minuscule. If not for your location, I would be looking for the eventual parts camera.
The knob actually has 4 components, two of which are press-fit together. The knob itself is fairly simple, it's just a tube with a wider knurled flange. In the bottom, it has a press fit bearing with two opposed teeth. There is an opposing washer with many more teeth that faces down against the knob teeth and is attached to the speed control shaft in the camera by means of the two-holed screw and it's oblong hole. When the speed setting knob is raised, the teeth mesh, allowing the shaft to be rotated and the speed of the shutter set. When let go, gravity pulls the knob back down which allows the shaft to rotate during exposure without dragging the knob along with it.
The only dimensions I am unclear on are the thread pitch of the screw. Based on measurements I could take, the threads per inch appears to be about 56, which would match a #2 UNC screw, but the diameter is closer to #1 UNC. It may be custom. All other dimensions are in thousandths of an inch.
My apologies for the delayed response. Since the forum changeover, it appears I am no longer receiving post reply notifications.
I took apart my speed setting knob and took dimensions for you, hopefully you find this helpful. I do believe it would be a very difficult task to replicate these components, as the machining operations are very minuscule. If not for your location, I would be looking for the eventual parts camera.
The knob actually has 4 components, two of which are press-fit together. The knob itself is fairly simple, it's just a tube with a wider knurled flange. In the bottom, it has a press fit bearing with two opposed teeth. There is an opposing washer with many more teeth that faces down against the knob teeth and is attached to the speed control shaft in the camera by means of the two-holed screw and it's oblong hole. When the speed setting knob is raised, the teeth mesh, allowing the shaft to be rotated and the speed of the shutter set. When let go, gravity pulls the knob back down which allows the shaft to rotate during exposure without dragging the knob along with it.
The only dimensions I am unclear on are the thread pitch of the screw. Based on measurements I could take, the threads per inch appears to be about 56, which would match a #2 UNC screw, but the diameter is closer to #1 UNC. It may be custom. All other dimensions are in thousandths of an inch.
Attachments
Adnei M A
Newbie
Dear Hcompton79, I thank you for your effort in helping! Disassembling the button, measuring and drawing the parts was time consuming , Thanks a lot! Very, very kind of you!
As you say, it's a rather complicated task to replicate one! I think that there not too many Ektras in Brazil. I never saw another one. I believe that this one could have been brought during the WWII period, when USAF utilized an air base to reach North Africa. At that time, the Natal Air base was the largest USAF base abroad. I think that there is almost no possibility of finding down here those parts I need.
Perhaps a fellow of rangefinder forum, reading your post, could give a hint on someone who has EKTRA parts, a dealer, for instance, I believe I will not find parts for EKTRA in Brazil.
I found a screw with the same thread as the the two hollowed one you gave me the dimensions. That one will be a feasible substitution. With your drawings and dimensions, I will start to find someone to work on the parts. At the same time I have a hope that a fellow from Rangefinder Forum could give a hint of a parts dealer.
I thank you enormously for your kind attention to me.
As you say, it's a rather complicated task to replicate one! I think that there not too many Ektras in Brazil. I never saw another one. I believe that this one could have been brought during the WWII period, when USAF utilized an air base to reach North Africa. At that time, the Natal Air base was the largest USAF base abroad. I think that there is almost no possibility of finding down here those parts I need.
Perhaps a fellow of rangefinder forum, reading your post, could give a hint on someone who has EKTRA parts, a dealer, for instance, I believe I will not find parts for EKTRA in Brazil.
I found a screw with the same thread as the the two hollowed one you gave me the dimensions. That one will be a feasible substitution. With your drawings and dimensions, I will start to find someone to work on the parts. At the same time I have a hope that a fellow from Rangefinder Forum could give a hint of a parts dealer.
I thank you enormously for your kind attention to me.
Ambro51
Collector/Photographer
I’ve read this thread with interest......all I can say is I will Never try to find/buy/fix an Ektra. There are TWO Ektras listed by Blue Moon Camera at the moment. One needs help, the other needs a miracle. Both cheap. 700 and 800. (I’ll pass)
peefeeniz
Never Again
I have an acquaintance who purchased a Leica from me… we were exchanging friendly emails until he wrote, excitedly, that he “scored” a mint Ektra outfit with several lenses from an elderly widow for only $200.
He has a wonderful and valuable collectible and no ethics.
He has a wonderful and valuable collectible and no ethics.
Ambro51
Collector/Photographer
$200? She done well. My Wife just plans a dumpster. Everything I collect will go in. Rare coins. Vermont Coppers, Civil War Firearms, about 100 Cameras, Charvet, Huntsman and Jack Taylor Suits. All in the dumpster...
DavidC
Established
I read somewhere that Howard Baker, of Watergate fame, had his Ektra serviced by a skilled Japanese technician (no name ) when he was ambassador in Japan. Baker also collected cameras in his spare time and was a well-known photographer.