Zeiss Ikon Contax Camera Repair

A home for your Zeiss Ikon Contax, Contarex or Super Ikonta camera!


There are some issues with the Contax due to its age and due to its design. The following warnings come out of experience and Zeiss literature.

  1. The Contax IIa and IIIa accessory shoe was designed for use only with accessory viewfinders. The accessory shoe is much weaker than it looks. In an early dealer bulletin Zeiss asked dealers to advise camera owners to use the camera shoe only with Zeiss accessory viewfinders. Zeiss advised that when a flash was to be used that it be mounted only on an accessory handle that mounts to the threaded tripod socket.
  2. Never use a wrist strap attached to the camera body strap lugs with the IIa and IIIa model cameras. The strap lugs have a weak point inside the camera. It is possible with a moderate amount of use for flexing of the lug to cause its stem to break off inside the camera causing the lug to pull out of the camera.

    The following picture is of a strap lug removed from the camera body. It's shown on a penny so you can get an idea of its size. You can see that the threaded hole for the attachment screw is drilled completely through the lug shaft. This means that only the little edges of the shaft on the side of the hole do the work when the camera is suspended from its strap lugs. The lug is made of brass that has been polished and chrome plated. It is not steel and so it doesn't have the strength of steel nor does it have the resistance to flexing steel has. The behavior of brass under flexing stress is to fail suddenly after a certain number of flexings. So if you are going to use your camera in a manner where you are going to use the body strap lugs to suspend the camera you must test the lugs on a very regular basis.

    body lugs

  3. Test the lugs occasionally by pulling on the strap if you are going to use the camera with a neck strap attached to the camera body strap lugs. It is very important to test the lugs on a regular basis. If a strap lug stem is ready to break the strap lug will pull out with surprisingly little force.

    This picture illustrates the danger of trusting the camera body lug straps. It is a picture of the left side body lug installation point in the body shell of a Contax IIa that was sent here for overhaul. This camera body was in factory original condition. The defect shown by this picture is an original factory manufacture defect.

    body lugs

    As you can plainly see the attachment screw is not completely tightened. The problem is that the threads in the shaft of the strap lug were improperly formed and so it was not possible for the screw to be threaded completely through the lug shaft. The lug shaft had been held in place by the use of epoxy cement. You can see the extruded excess epoxy coming out of top of the shaft end just below the screw. But the epoxy does not adhere well to highly polished chromium plated brass, which is the material the lug shaft is made of. This is a lug strap that was a disaster in waiting. The lug shaft was really only being held in place by friction and had this camera been used with a wrist strap attached to this strap lug, it would have hit the pavement hard sooner or later.

    With regard to the earlier pre war II and III model cameras the side lugs are attached to the camera frame in a much different and much stronger manner than the post war IIa and IIIa model cameras. It is safe to use a good high quality wrist strap with the II and III model cameras.

  4. Never use old leather straps on a Contax camera case. If you buy a Contax and it comes with a case do not trust the leather straps no matter how firm or good they look. Even the best leather slowly looses its strength over time and 50 year old leather straps will suddenly fail if put into use. Before using an old Contax case have the straps replaced by a professional leather worker.
  5. Never ever store the camera in a car trunk. The temperature in a car trunk can rise to over 200 degress in moderate weather. This temperature is greater than the melting temperature of the optical cement used in the camera viewfinder prism and in many Contax lenses. An overheated lens will have black specks which upon close examination are large bubbles of gas which is the byproduct of overheated lens cement.
  6. Do not use electrical humidity control cases: These appliances are marketed in areas of high humidity. The way they work is that an air circulation fan circulates the air in the cabinet through a chemical dessicant cartridge that absorbs the moisture from the air before it is returned to the cabinet interior. An electrical heater periodically regnerates a chemical dessicant cartridge. The idea is simple, but a lot can and does go wrong with these cabinets. The cabinets contain an electrical heater that is periodically activated by a timer to heat the dessicant cartridge to a temperature of about 350 Degrees Farenheit to regenerate the cartridge.

    The controls needed to maintain the cabinet are complex and liable to failure. Ideally, the air circulation fan will stop during the regeneration process. But sometimes it keeps running and the cameras in the enclosure get baked to a temperature in excess of 250 degrees. Another problem is that sometimes the vent valve that directs the moisture from the regenerating dessicant outside of the box doesn't work and all the water the dessicant absorbed is discharged to the inside of the cabinet. The result is that when the regeneration cycle is complete the water that was driven out of the cartridge is inside the case and the dessicant is immediately saturated when the circulation fan begins to run again. The door seals on such cabinets are prone to fail with the result that the cabinet is completely ineffective.

    Zeiss recommended that in humid climates the camera be kept out in the open on a dry shelf where the air can circulate. They did not recommend a humidity control cabinet. These cabinets were being sold at the time the Contax IIa and IIIa were being made. Zeiss knew about them and so if they were a good idea Zeiss would have recommended them.

  7. Always store the camera with the shutter discharged: Shutter springs will take a "set" if they are kept tensioned for a long period of time. The Contax RF cameras are all at least 50 years old and so they have shutter springs that will take a set very easily. This set will change the accuracy of the shutter and in some cases may require a complete camera recalibration.
  8. Always exercise the camera through all of its speeds at least once every two weeks during inactive periods: Shutter components need to move to keep lubricants from migrating away from points of friction. Regular exercise keeps a shutter accurate.
  9. Use extreme care when intalling filters on lenses: The 40.5 mm filter size turns out to have two properties which explain why no one makes it today. The first is that it is incredibly easy to cross thread when installing a filter and the second is that it is prone to becoming stuck on hard when even slightly over tightened. These unpleasant properties are magnified when a brass (hard alloy) filter is installed on an aluminum (soft) lens filter bezel. The way to avoid these problems is to use three techniques. Always rotate the filter by pinching it with two fingers. Never use the whole hand to rotate the filter while installing it. Then when a filter is being installed rotate it very gently one turn to set it into the threads properly, then rotate it backwards one half turn to test it is not cross threaded.

    If it turns backward easily it is safe to gently, very gently, bottom it on the lens. Then, once its bottomed, rotate it back slightly to ensure it is not stuck. The word is two finger gently SNUG and not hand TIGHT. A filter that is very very gently snugged will come off easily. One that has been tightened will not. If you encounter a filter that resists removal to the point where more force is required than is necessary to remove a fine $200.00 pair of leather kid gloves from your hands it's time to stop what you are doing and write to me. I have special tools and techniques to remove a cross threaded or stuck on filter without damaging the lens or the filter.

    Keep in mind that an attempt to remove a stuck filter from a Biogon can result in extensive, severe and perhaps unrepairable damage to the aperture control mechanism. When in doubt its best to have me remove the filter when its stuck on a rare and expensive 35mm or 21mm Biogon lens.

  10. Never Take Your Camera to the Beach: Disposable cameras that can be purchased at the supermarket or drug store are made for the beach. The Contax is not sealed against dust and dirt. If you take your camera and/or lenses to the beach you can be sure that when you get them home their controls are going to be rough and crunchy from small sand particles that found their way inside the camera. If this happens to you the only remedy is to immediately send the equipment to me to be properly cleaned.
  11. Be Extremely Careful When Buying The 50 mm f1.5 Sonnar Lens: There is a lens separation problem that can develop suddenly with some 50mm 1.5 Sonnar lenses. This separation problem is caused by deterioration of the experimental epoxy type lens cement used to cement the center element of this lens which is made of three lenses cemented together. It has come to my attention that a cheap and easy, but temporary and ruinous method of correction of this separation has been found and is being used by uscrupulous and dishonest workers to "correct" and improve this separation.

    There is an industrial oil available for use in determining the index of refraction (hardness) of clear substances such as glass, jewels and plastics. This oil is avaiable in a great range of indices of refraction. When a clear object is immersed in this oil it will effectively disappear if the index of refraction of the object is close to that of the oil.

    It has been discovered that if a drop or two of this oil having the same index of refraction as the glass used in the Sonnar triplet is applied to the edge of a separated triplet, the oil will infuse into the separated section and will make the separation effectively disappear.

    The problem with this solution is that it is temporary. The oil also accelerates the separation of the lens resulting in its complete ruin in the progress of time.

    This method is not used here. Lenses are tested to determine if this method has been used prior to sale and such lenses are not sold.

    You can see a picture of the type of separation that is being "corrected" through the use of this destructive process by using this link: Separated Triplet.

  12. Always Wind the IIa and IIIa Cameras to the FULL STOP: There is a latch in the shutter mechanism which absolutely must engage fully for the high speeds of 1/250 to 1/1250 to function accurately and reliably. This latch engages right at the end of the wind. It is very important when winding your IIa or IIIa camera to wind the camera until the wind knob is stopped by the end stop. This will ensure the shutter latch is fully engaged. There's no need to worry about damage to the camera using this method. This part of the camera was made to be very strong and so it's always a good idea to add a little additional torque at the end of the wind just to make sure. You can determine when this latch engages by listening to your camera. Hold the center of the top plate close to your ear while it the camera is slowly wound. Right towards the end of the wind you will hear two clicks. One will be loud and the other will be soft. The loudest will be first. It is the backwind prevention latch engaging. The second, softer click will be the shutter high speed latch engaging.
  13. The Shutter Release Button Must be Operated Differently than the Leica: The Leica and Contax shutter designs are greatly different from each other. This design difference requires a different technique of shutter release at the high speeds of 1/250 to 1/1250 with the Contax. With the Leica the shutter release button is very slowly pushed down until the shutter releases. With the Contax the shutter release button must be pushed down quickly but smoothly to the bottom stop. This technique difference is not so important at speeds less than 1/250, but it is absolutely necessary for accurate and reliable operation of 1/250 through 1/1250.
  14. Never Force the Contax Rewind Knob: The part of the rewind knob that attaches to the rewind shaft on the Contax I through g, IIa and IIIa bodies is very thin. It is easily possible, with hand pressure, to damage the rewind knob beyond repair if an attempt is made to force a camera with a jammed rewind. The only solution to this problem is to send the camera here for the source of the jam to be determined and properly corrected. If the rewind knob is damaged it will be extrordinarly expensive to replace on a IIa or IIIa, and may be impossible to replace on a Contax I.
  15. Never Force the Wind Knob at the End of a Roll of Film: If the end of a roll of film is reached before the end of a wind the wind knob will stop. It is common in the Contax for inadvertent hand swipes to alter the position of the film frame counter which results in the end of a roll of film occurring part way through a wind. When the film advance knob is forced at the end of a roll of film the film advance sprockets tear off little tabs of film and inject them directly into the innermost shutter mechanism gears. I see many cameras that contain these film chips and they are a common source of shutter problems. While they are a simple problem, complete removal of all of them requires a complete camera disasembly which is an expensive procedure.


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