Screw Mount Leica Cameras – Managing Expectations

​

Leica screw mount cameras span more than 25 years of development. While they may look very similar externally, there were significant mechanical changes over that period. This means that two cameras that appear almost identical on the outside can behave quite differently in use – even after careful professional servicing.

​

We continue to service and restore screw mount Leicas thoroughly and sympathetically. In fact, older cameras often demand more time and attention than even 'M' models. However, with the very earliest designs there are unavoidable limits to what can be achieved in terms of accuracy and repeatability, simply due to wear and the technology of the time. For this reason, we believe it’s important to be open and realistic about what you can expect from different generations of camera.

​

Early Screw Mount Cameras (Leica I, II, III, IIIa, IIIb – pre-IIIc) Full Service (FS)

​

These early cameras are beautifully made and historically important, but their shutter design reflects 1920s–1930s engineering. The focal-plane shutter relies heavily on spring tension, friction surfaces and the geometry of the shutter drums and rollers. Unlike later designs, there is less rigid support of the moving parts, and no modern-style bearing races or positively guided drum assemblies.

Over many decades of use, natural wear occurs in areas such as:

​

• Shutter drum bearings and shafts

• Curtain rollers and their supports

• Release and braking components

• The slow-speed escapement

​

As wear accumulates, small amounts of play and misalignment develop within the shutter mechanism. Even after careful cleaning, lubrication and adjustment, this can limit how accurately and how consistently certain shutter speeds can be set and maintained.

​

In practical terms:

​

• High speeds -1/500th, (1/1000th on the IIIb)
  These are the most sensitive to wear and tolerances. On some early cameras, especially IIIb models with 1/1000th, achieving textbook accuracy across the full frame may simply not be possible anymore. We can usually optimise performance, but repeatability and absolute accuracy may remain limited by the mechanical condition and design of the camera.

• Intermediate speeds
  These can vary more from nominal values than on later models, particularly where fine adjustment is limited by the original design.

• Slow speeds (1/20th – 1 second)
  These are governed by a separate escapement. While wear can introduce some deviation from nominal timings, slow speeds are often consistent and perfectly usable in practice once properly serviced.

​

With early cameras, servicing often overlaps with restoration. This is especially true of black paint models, where cosmetic conservation, sympathetic cleaning and preservation of original finishes form part of the work. These cameras are as much historical objects as they are photographic tools, and our approach reflects that.

​

The important point is this:
A fully serviced pre-IIIc Leica can be a wonderful, usable camera – but it should not be judged by modern expectations of mechanical precision or compared directly to later screw mount models.

​

Later Screw Mount Cameras (Leica IIIc, IIIf, IIIg)

​

From the Leica IIIc onwards, Leica introduced significant internal improvements to the body and shutter assembly. These cameras use a more rigid die-cast body shell and improved support for the shutter drums, including proper bearing races. This results in:

​

• More stable shutter geometry

• Less lateral movement and end float

• Reduced sensitivity to wear

• More repeatable shutter timing

​

In real-world terms, this means that later screw mount Leicas can generally be adjusted to achieve more consistent and predictable shutter speeds, particularly at the higher settings. They are also more tolerant of long-term wear and previous use, and their performance envelope is closer to what most users would intuitively expect from a “properly serviced” camera.

​

What Our Servicing Aims to Achieve:

​

Our aim is always to make your camera as reliable, usable and mechanically sound as its design and condition realistically allow. We do not take shortcuts, and we often spend more time on older screw mount cameras than on later M cameras because they are mechanically more demanding to work on.

However, with early pre-IIIc cameras, there are limits imposed by:

​

• Original design constraints

• Long-term wear of critical components

• The absence of later engineering refinements

​

Rather than offering a blanket “full service/overhaul” label, we prefer to be honest about these realities and manage expectations accordingly. This allows us to deliver the best possible outcome for each individual camera without promising performance that the design itself can no longer reliably deliver.

If you’re unsure where your camera sits within this development timeline, we’re always happy to advise.

​

​

​Leica IIIf and IIIg - FS (Full Service)

​

The Leica IIIf and IIIg (and to some extent IIIc), are more 'modern' cameras and while the general shutter arrangement is similar to earlier cameras, the shutter and transport engineering evolved to make use of better materials and construction, ball bearings as well as fine adjusters for 1/500th speeds and below and for 1/1000th. As a result, we are more confident in returning the camera to correct functionality. For these cameras we carry out a full and more detailed service/overhaul including calibration of the shutter to the correct standard. This includes shutter tensions and slit width adjustments. The calibration of a focal plane shutter allows for 1/3rd stop deviation, that is 1/500th overall shutter speed but more importantly, the deviation in exposure from one side of a negative to the other should also be within 1/3rd of a stop. This is usually the case at 1/1000th but if in certain cases, if camera has experienced a great deal of wear and tear, the deviation may exceed 1/3rd of a stop. In general, we favour getting 1/500th and below to be as accurate as possible at the expense of a slight loss of accuracy at 1/1000th although in most cases, the camera should be perfectly useable at that shutter speed without an impact on performance.

​

Leica M – Full Service / Overhaul (FSO)

​

We do not offer a generic “CLA” (Clean, Lubricate and Adjust) service on Leica cameras. The term CLA is widely used within the industry, but it can mean different things to different people and does not describe a defined service standard. For clarity and consistency, we work to a full service / overhaul (FSO) standard that follows Leica’s own service philosophy and specification.

​

Any Leica M camera booked in for servicing will receive a full mechanical strip-down and overhaul to this FSO standard. While the exact work required varies depending on condition, age and prior service history, the following gives a good overview of what is involved.

We strongly recommend that you tell us about any issues you have experienced with the camera, especially intermittent faults, so that these can be specifically checked during the service.

​

Mechanical Service

​

• All shutter components cleaned and lubricated to the correct specification

• Baffle removed and repainted if required

• Baffle plush strips removed and re-glued or replaced as necessary

• Slow-speed escapement cleaned and bearings lubricated

• Shutter curtains inspected for holes, damage or curling (curling can lead to light leaks)

• Blind tensions reset, shutter slit width calibrated, and shutter speeds set to standard

• Transport mechanism cleaned, serviced and re-timed

• Advance block serviced, including inspection and adjustment of the forward transport clutch

• Worn parts refaced or replaced where required

• Shutter brake serviced and new friction disc fitted

• Flash synchronisation checked and contacts cleaned

• Rewind mechanism serviced; on M4 and later models the take-up spool clutch and rewind action are checked to ensure smooth, correct operation

​

Rangefinder and Optical System

​

• Rangefinder assembly serviced and calibrated from 1 metre to infinity

• Minor remedial work carried out as required

• In some cases, more extensive work may be needed, such as prism repair or full rangefinder rebuild (for example, in cases of blacked-out or severely degraded rangefinder optics).
  This level of work is not normally required during routine servicing and would be quoted separately. Please see our pricelist for standalone rangefinder repairs.

​

Seals, Coverings and Finishing

​

• New light seals fitted as required

• Minor localised vulcanite repairs carried out where possible as part of the service

• If a full re-skin is desired, this should be requested separately

• On completion, cameras originally fitted with a black wax seal on the lens mount are resealed with our own workshop seal, impressed with a “W” to indicate that the camera has been serviced by us

• A written service report is provided with every serviced camera

​

Exclusions

​

Certain items fall outside the scope of a standard service/overhaul unless specifically requested or found to be necessary, including:

• Shutter curtain replacement

• Strap lug replacement

• Major component replacement

• Full rangefinder rebuilds or prism repairs

​

If additional work is required, we will normally contact you to discuss options and costs. In many cases, carrying out related work while the camera is already dismantled is more cost-effective than deferring it to a later date.

​

Spot Repairs

​

If your camera has been serviced relatively recently and is otherwise performing well, it may be possible to address specific faults without carrying out a full service. Examples include:

• Frame counter faults

• Dents

• Replacing windows

• Rangefinder calibration

• Rangefinder prism movement causing repeated loss of alignment

• Sticking Rangefinder Arm (M10)

​

Some of these jobs are listed in the standalone work section of our pricelist, while others may be charged on a labour-only basis.

​

Please note that spot repairs can sometimes be a false economy if the camera is fundamentally overdue for a full service. If you are unsure, you are welcome to send the camera in for assessment. We do not charge for inspection. If no work is carried out, you only pay return postage.