The short answer is yes, you can shoot 600 film in an SX-70 Sonar camera, but it requires modification or an external ND filter. Attempting to use 600 film directly in an SX-70 camera will almost always result in overexposed, unusable photographs due to the significantly higher light sensitivity of the 600 film.
Understanding the Core Issue: Film Speed & Light Sensitivity
The heart of the problem lies in the difference in film speed, specifically the ASA (American Standards Association) rating, which indicates a film’s sensitivity to light. SX-70 film has an ASA of 160, making it relatively slow and requiring more light for proper exposure. Conversely, 600 film has an ASA of 640, making it four times more sensitive to light.
The SX-70 Sonar camera, while sophisticated for its time, is designed with a specific light metering system calibrated for the lower ASA of SX-70 film. When you insert 600 film, the camera’s light meter still operates under the assumption that the film requires a certain level of illumination. Because the 600 film is much more sensitive, it receives far too much light, leading to overexposure. This overexposure often manifests as washed-out images with little to no detail.
Solutions: Modification and Mitigation
Thankfully, the problem isn’t insurmountable. Several strategies allow you to successfully use 600 film in your SX-70 Sonar:
1. The ND Filter Method: Simple and Reversible
The most common and arguably the easiest method is to use an ND (Neutral Density) filter. These filters reduce the amount of light entering the camera lens. For using 600 film in an SX-70, you generally need an ND filter that reduces light by approximately two stops (ND2 or ND4).
- How it works: The ND filter acts as a “sunglasses” for your camera, blocking a portion of the incoming light. This forces the camera’s light meter to compensate by allowing more light to pass through, effectively mimicking the conditions required for SX-70 film.
- Advantages: Relatively inexpensive, easy to apply and remove, doesn’t permanently alter your camera.
- Disadvantages: Requires remembering to use it, can affect image sharpness slightly depending on the filter quality.
2. Modifying the Film Cartridge
Some enthusiasts modify the 600 film cartridge itself. This involves placing a thin piece of ND filter gel over the light meter eye inside the cartridge. This darkens the light sensor, tricking the camera into thinking it needs more light.
- How it works: By darkening the sensor, you essentially force the camera to open the aperture for a longer period, compensating for the 600 film’s increased sensitivity.
- Advantages: A more integrated solution than using an external filter.
- Disadvantages: Requires a degree of technical skill and may void any warranty on the film (if there were one). Can be messy if not done carefully.
3. Electronic Modification (For Advanced Users)
For those with electronic expertise, modifying the camera’s light meter circuit is a possibility. This involves adjusting the light meter’s calibration to account for the difference in film speed.
- How it works: This is the most complex solution, requiring altering the camera’s internal circuitry.
- Advantages: Potentially the most elegant solution, allows for seamless switching between SX-70 and 600 film.
- Disadvantages: Highly technical, requires specialized knowledge and tools, may permanently damage the camera if not done correctly.
Alternative Uses: Overriding the Automatic System
While not ideal, there is another (less reliable) option:
- Manual Override: The SX-70 Sonar has a lighten/darken wheel. While using 600 film with the lighten/darken wheel alone isn’t a perfect solution, aggressively dialing towards “darken” can sometimes yield usable (albeit unpredictable) results. This method is heavily dependent on the lighting conditions and requires significant experimentation.
FAQs: Deep Dive into SX-70 and 600 Film Compatibility
Here are some commonly asked questions to further clarify the nuances of using 600 film in an SX-70 Sonar:
FAQ 1: Why does 600 film work in some SX-70 cameras without modifications sometimes?
This is likely due to a combination of factors, including variations in manufacturing tolerances of both the camera and the film, as well as the specific lighting conditions. In exceptionally bright environments, the camera might compensate enough to produce a usable image, but this is not a reliable outcome.
FAQ 2: Can I use a Polaroid OneStep camera with SX-70 film?
No. The Polaroid OneStep camera is designed for 600 film and cannot be used with SX-70 film. The OneStep lacks the necessary light sensitivity range to expose SX-70 film correctly, resulting in underexposed images.
FAQ 3: Will using 600 film damage my SX-70 camera?
No, using 600 film won’t physically damage your camera. The risk lies in the wasted film and the frustration of consistently overexposed images.
FAQ 4: Are there any SX-70 cameras that natively support 600 film?
No, no original SX-70 cameras were designed to use 600 film without modifications. There are modern instant cameras that are compatible with both film types.
FAQ 5: Where can I buy ND filters for my SX-70 lens?
ND filters specifically designed for the SX-70 are readily available online from various photography retailers and marketplaces. Search for “SX-70 ND filter” or “Polaroid ND filter.”
FAQ 6: What is the difference between ND2 and ND4 filters?
ND2 filters reduce light by one stop (halving the light), while ND4 filters reduce light by two stops (quartering the light). For 600 film in an SX-70, ND4 is generally recommended.
FAQ 7: How do I know if my ND filter is working correctly?
The best way to test is by taking test shots in different lighting conditions. If the images are still overexposed, you may need a stronger ND filter.
FAQ 8: Can I stack ND filters to achieve a greater light reduction?
Yes, you can stack ND filters. For example, combining an ND2 and an ND4 filter would provide a total light reduction of three stops.
FAQ 9: Is it worth the effort to use 600 film in an SX-70?
This depends on your personal preferences and resources. SX-70 film generally provides more accurate color rendition and a slightly softer image, but 600 film can be more readily available and sometimes more affordable. If you already have 600 film, an ND filter offers an affordable solution.
FAQ 10: Does the Sonar focusing system affect exposure when using 600 film?
The Sonar focusing system primarily affects the lens’s focus, not the exposure. The light meter is a separate system that needs to be addressed with an ND filter or modification.
FAQ 11: Can I use the “Lighten/Darken” wheel as a reliable solution?
While the lighten/darken wheel can offer some adjustment, it’s not a reliable substitute for an ND filter or other modification. It might help in specific lighting situations, but consistent results are unlikely. Think of it as a last resort, not a primary solution.
FAQ 12: What happens if I use 600 film without ANY modification?
You will almost certainly get severely overexposed images. The film will be washed out, lacking detail and contrast, making it virtually unusable.
Conclusion: Experimentation and Informed Choices
Using 600 film in an SX-70 Sonar is entirely feasible, but requires careful consideration and the implementation of appropriate methods to compensate for the difference in film speed. By understanding the underlying principles and exploring the available solutions, you can unlock new creative possibilities and enjoy the convenience of shooting with 600 film in your beloved SX-70. Remember to experiment and find the method that best suits your needs and photographic style. Happy shooting!