One of the most popular cameras of the 1990s, it is a modern classic – an affordable, stylish, light, small, splash proof camera with a fast and sharp lens coupled with accurate AF. There’s almost no downside to the camera and it is no wonder that Olympus sold almost 4m of this particular model worldwide.

It is one of the cameras I was most excited to modify to fit on my digital cameras. The process itself, however, was far from easy and involved many iterations of the final version of the adapter which I am showcasing here. The challenges were mainly to do with the extraction of the lens unit and then the designing of the adapter which would articulate the shutter/exposure mechanism which is conveniently integrated within the lens assembly unit – which can be extracted (with difficulty) as a single unit. More information can be found in the appropriate project areas.

Lens: 35mm, f/2.8, focusing from 0.35m-infinity. (4 elements in 4 groups)

Optical system construction: Lens is encased in an extended mono block plastic cylinder with 4 lugs which hold the lens block in place on a focusing platform. Also attached to the unit is a combination aperture and shutter mechanism.

Shutter and Aperture: Combined Shutter/Aperture mechanism, single set of 3 blades. Iris is a non linear triangle shape.

Common Failures:

  1. Battery door failure – very common and replaceable, unless the surrounding area where the door is mounted is also damaged (also common). Tape is crude and effective way to cure this but, inevitably, this is one of the most common source for cheap Mjus on sale on eBay
  2. Film Transport/micro switch failures: many symptoms for this, ranging from total failure in transport operability, to partial failure with some forms of film transport and flash failure. The latter is caused by the micro switch failure which syncs shutter to flash operations. Both are interlinked and made mainly out of plastic, which has a tendency to fail. Transport mechanism failures can be fixed using gearing from a donor camera but micro switch failures are almost impossible to fix.

Lens Removal:

This is guide on how to remove the lens out of a Olympus Mju II. It is NOT a repair manual. All the cameras I extract lenses from are beyond repair and my method of removing lenses is based on the easiest way of removing the lens at the expense of the donor camera.

The Olympus Mju II is a very densely packed camera, it’s compact form factor means that everything is very tightly packed into the compact body.

disassemble_1Step 1 – Separate the front and back clamshell 

The Olympus Mju II is a splash proof camera and front and rear clamshells are designed to keep moisture out of the camera. The first step is to separate these two by popping open the rear film chamber door and removing the screws highlighted in orange

Step 2 – It gets ugly, you get creative

See a screw, remove a screw. That is the basic idea. The good news is that most of the parts are plastic so where there is resistance, its relatively easy to break the bits that stand in the way to you getting to lens. There is no way of extracting the lens without sacrificing the camera in entirety, be very clear about this. It’s not a case of being careful, some of the parts in the camera are welded together and can only be forcefully separated, with no chance of reassembly.

The Prize. The extracted lens unit is approximately 24mm at it’s widest (not including the lens mounting lugs) and 25 mm high.

The rear of the lens. Note the large and bulbous rear element (compared to the front). This throws light at acute angles towards the edges.

Rear, the aperture/shutter wide open. Actuation of the aperture/shutter is via a tab in the bottom right of the lens unit.


Aperture/shutter closed down approximately half way. Note the triangular aperture. The aperture/shutter will close down completely when fully articulated.

Method of conversion:

  • Complex 3d printed mount in two parts, secured with a screw
  • Lens mounted between base of the mount and secondary enclosure
  • Base unit  has prongs to articulate shutter/aperture blades
  • Mount coupled to Leica M mount close focus helicoid

The adapter mount consists of two pieces – a base unit and a lens mount, which also has a handle to articulate the lens unit’s aperture/shutter mechanism

The lens unit mounts onto the lens mount piece by friction fit. It will be farther secured when attached to the base unit which has a lip to prevent the lens and mount units from travelling


The lens and lens mount unit is attached to the base unit. The base unit has a pair of prongs to articulate the shutter/aperture mechanism

The base unit has a slit to allow for the articulation of the shutter/aperture mechanism


The anchor screw attaches to the lens mount unit via a point which is printed in the lens mount unit. Here, I’m showing the mounting point without the outer base unit attached.

The final, assembled adapter, with both units attached. The lever on the bottom left is used to articulate the shutter/aperture mechanism.

Sample Images

Sony A7M2, 35mm f3.5, 1/3200th sec, ISO 100
Sony NEX-6, 35mm f3.5, 1/200th sec, ISO 100
Sony A7M2, 35mm f3.5, 1/250th sec, ISO 100

Some initial photos taken with the lens, full resolution versions and more photos taken with the lens can be found in on my Flickr album

Results and Conclusion:

The Mju II is the first real disappointment I’ve had so far (I’m sure that there will be more) in my efforts to convert compact camera lenses to work on digital cameras.

As you can see, the results from the images I have used to summarise the lens performance, the images are tack sharp in the centre but this sharpness rapidly disappears towards the edges. Additionally, closing the aperture/shutter blades does little to increase the depth of field of the image captured or increase edge sharpness.

The main culprit for this is the, bulbous, wide rear element which spreads the image from the lens across the size of a 35mm frame. The flange distance between this element and the film plane is very small – approx 9 millimetres. The last element in the lens group does this by distributing light onto the film plane at very acute angles. Fine if it the final capturing medium is film, not so good if the capturing is being done by a digital sensor with a (relatively) thick piece of glass in front of it. The results are a distinctively smeared image and there’s nothing that can be done about it.

It’s a major disappointment as this is undoubtedly a very sharp and fast lens. Being able to utilise this on digital cameras would have been a major achievement. As it stands, I cannot recommend that you try to convert this lens for any practical purpose. The narrow flange distance and rear lens element characteristics mean that you will never be able to overcome the edge performance characteristics with the current digital sensor technology.

Additionally, the 9mm gap means that the converted lens will not mount on most APS-C sensor cameras as most of them have a blanking plate around the sensor which will prevent mounting of the lens. The lens (with enclosure) diameter is wider than an APS-C sensor so it will only mount on a full frame sensor camera.

Having said that, I learnt a lot converting this lens and look forward to seeing how it can potentially perform on my M mount film cameras, using hyperfocal focusing. Watch this space, as they say.

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