How to Fix Overlapping Frames on a Hasselblad CM Back

The Hasselblad CM back is a popular choice for photographers who want the quality and versatility of a medium format system. However, like any camera, it can experience problems from time to time. One common issue is overlapping frames, which can occur when the film wind mechanism malfunctions. This can be a frustrating problem, but it is often easy to fix.

In this blog post, we will provide a step-by-step guide on how to fix overlapping frames on a Hasselblad CM back. We will also discuss some of the common causes of this problem and how to prevent it from happening in the future.

Understanding the Problem

The Hasselblad CM back uses a spring-loaded mechanism to advance the film. When this mechanism malfunctions, the film may not advance properly, leading to overlapping frames. This can happen for a number of reasons, including:

• A worn or damaged spring
• A stuck or broken gear
• A dirty or obstructed film path

Troubleshooting and Repair

Before attempting any repairs, it is important to make sure that the problem is not caused by something simple, such as a stuck film cassette or a loose film advance lever. If you have ruled out these possibilities, you can proceed with the following troubleshooting steps:

1. Inspect the Film Advance Lever: Make sure that the film advance lever is moving freely and that it is not sticking or binding. If it is, you may need to clean or lubricate it.
2. Check the Film Cassette: Ensure that the film cassette is properly inserted and that it is not loose or damaged. A loose cassette can cause film advance issues.
3. Examine the Film Path: Inspect the film path for any debris or obstructions. If you find any, carefully remove them.
4. Test the Film Wind Mechanism: Try advancing the film manually by turning the film advance lever. If the film does not advance smoothly, you may need to open the back and inspect the mechanism.

Repairing the Film Wind Mechanism

If you have determined that the problem is with the film wind mechanism, you will need to open the back of the camera and inspect the mechanism. This should only be done by experienced individuals, as it requires a good understanding of the inner workings of the camera.

Here are the general steps involved in repairing the film wind mechanism:

1. Remove the Back: Carefully remove the back of the camera. Be sure to note the position of any screws or parts that you remove.
2. Inspect the Mechanism: Examine the film wind mechanism for any signs of wear, damage, or debris. Pay particular attention to the spring, gears, and film path.
3. Clean and Lubricate: Clean any dirt or debris from the mechanism using a soft brush and compressed air. Apply a small amount of lubricant to the moving parts, such as the gears and the spring.
4. Replace Damaged Parts: If any parts are damaged, they will need to be replaced. You can purchase replacement parts from authorized Hasselblad dealers.
5. Reassemble the Back: Once you have repaired the mechanism, carefully reassemble the back of the camera. Make sure that all parts are properly aligned and that the screws are securely fastened.

Preventing Overlapping Frames

Here are some tips for preventing overlapping frames on a Hasselblad CM back:

• Use High-Quality Film: Using high-quality film can help to reduce the risk of film advance problems. Damaged or old film can be more prone to jamming or tearing.
• Keep the Camera Clean: Regularly clean the camera and the film path to prevent debris from accumulating. This will help to ensure that the film advances smoothly.
• Avoid Extreme Temperatures: Extreme temperatures can damage the camera and its components. Store the camera in a cool, dry place.
• Handle with Care: Handle the camera with care to avoid damaging the film wind mechanism. Avoid dropping or bumping the camera.

Conclusion

Overlapping frames on a Hasselblad CM back can be a frustrating problem, but it is often easy to fix. By following the troubleshooting and repair steps outlined in this blog post, you can get your camera back in working order and continue to enjoy the benefits of using a medium format system.

If you are not comfortable repairing the camera yourself, you can always take it to a qualified technician. However, by understanding the problem and the repair process, you can save yourself time and money in the long run.