Pentax 67 300mm Lens Repair: Cleaning the Diaphragm Unit

Pentax 67 300mm Lens Repair: Cleaning the Diaphragm Unit

This video tutorial demonstrates how to access and clean the aperture blades of a Pentax 67 300mm lens. The process involves removing the front and rear lens groups to reach the diaphragm unit. This repair technique is applicable to classic cameras and can be helpful for anyone interested in maintaining their vintage equipment.

Before you begin, gather the following tools:

• Small screwdriver set
• Lens cleaning kit (including lens cleaning fluid and a microfiber cloth)
• A clean, dust-free workspace

Step 1: Remove the Front and Rear Lens Groups

1. Carefully detach the front and rear lens groups from the lens barrel. These groups are typically held in place by screws or retaining rings. Be mindful of the order in which you remove them, as you'll need to reassemble them in the same order.

2. Once the lens groups are removed, you should be able to see the diaphragm unit. This unit is responsible for controlling the aperture of the lens.

Step 2: Accessing the Diaphragm Unit

1. The diaphragm unit is typically accessed by removing a small cover or plate. This cover may be secured by screws or clips. Remove it carefully, taking note of any specific alignment or orientation.

2. Once the cover is removed, you should have access to the diaphragm blades. These blades are responsible for opening and closing the aperture of the lens.

Step 3: Cleaning the Diaphragm Blades

1. Use a lens cleaning fluid and a microfiber cloth to gently clean the diaphragm blades. Avoid using excessive force, as this could damage the blades.

2. Pay close attention to any debris or dust that may be stuck between the blades. Use a small, soft brush or a blower to remove any stubborn particles.

Step 4: Reassembly

1. Once the diaphragm blades are clean, reassemble the lens in the reverse order of disassembly. Make sure to align all parts properly before tightening any screws or clips.

2. Once the lens is reassembled, test it to ensure that the aperture mechanism is working properly. You can do this by taking a few test shots at different aperture settings.

Important Notes

• If you are not comfortable with this repair process, it is best to take your lens to a professional camera repair technician.
• Always be careful when working with delicate mechanical parts. Avoid using excessive force, as this could damage the lens.
• Use only lens cleaning fluid that is specifically designed for camera lenses. Avoid using harsh chemicals or solvents, as these could damage the lens.

Conclusion

By following these steps, you can effectively clean the diaphragm unit of your Pentax 67 300mm lens. This will help to restore the lens's performance and ensure that it continues to provide sharp, clear images. Remember to always work carefully and follow the manufacturer's instructions.