The Weston WX-7 is more than just a light meter; it’s a portal to understanding light and achieving perfectly exposed photographs with your film camera. To effectively use a Weston WX-7, you must learn to correctly read the meter, understand its limitations, and translate its readings into appropriate aperture and shutter speed settings for your chosen film speed.
Understanding the Weston WX-7: A Journey into Classic Light Metering
The Weston WX-7, a selenium cell light meter, represents a pivotal era in photographic history. Unlike modern digital meters that use batteries and complex circuits, the WX-7 relies on the photoelectric effect of selenium to generate a current when exposed to light. This current is then measured by a sensitive galvanometer, which displays a light value. This value, in turn, allows you to determine the appropriate aperture and shutter speed combinations for your camera. While seemingly simple, mastering the WX-7 requires understanding its quirks and limitations. The WX-7 doesn’t provide digital readings. Instead, it gives a numerical reading that corresponds to exposure values on a dial. You then manually adjust the dial based on your film’s ISO, atmospheric conditions, and desired outcome.
Initial Steps: Preparing Your Weston WX-7
Before taking your first reading, there are a few crucial steps to ensure your WX-7 is ready for action.
Battery-Free Operation and Selenium Cell Health
The beauty of the WX-7 is that it doesn’t require batteries. Its inherent dependency on the selenium cell demands the most immediate focus.
- Selenium Cell Check: The most important factor is the health of the selenium cell. Older meters may have deteriorated, providing inaccurate readings. A simple check is to compare its readings against a known accurate light source (like a modern digital meter) or against a reliably lit scene described in your film’s documentation. If the readings are consistently off, the selenium cell might be nearing the end of its life. There is no straightforward repair, sadly.
Setting the Film Speed
Setting the correct film speed (ISO/ASA) is fundamental.
- Locate the ISO Dial: The Weston WX-7 features a rotating dial for selecting the film speed. This dial is often found on the top or back of the meter.
- Match to Your Film: Carefully rotate the dial until the indicator aligns with the ISO value of your film. Double-check this setting – an incorrect ISO will lead to significant exposure errors. Modern films are often listed using the ISO scale; earlier films generally used ASA.
Taking a Reading: Mastering the Weston WX-7 Technique
Accurate light metering is the cornerstone of successful film photography.
Understanding Incident vs. Reflected Light Metering
The WX-7 is primarily designed for reflected light metering, meaning it measures the light reflected off the subject. However, some models may have an optional incident light attachment (usually a white diffuser dome).
- Reflected Light Metering: Point the meter towards your subject from your camera’s position. Be mindful of the meter’s angle of view – it should roughly correspond to the angle of view of your lens. The WX-7 does not have an “averaging” feature. It will be most influenced by whatever the meter is pointed at. Be careful to avoid pointing at very bright or very dark areas, or you may significantly over or under expose your image.
- Incident Light Metering (with attachment): If you have an incident light diffuser, hold the meter near the subject, pointing the diffuser towards the light source. This measures the light falling on the subject, rather than what’s reflected. Incident metering is often more accurate, especially in scenes with high contrast.
Interpreting the Meter Reading
After taking a reading, the meter needle will settle on a number. This number corresponds to a specific exposure value on the rotating dial.
- Matching the Needle to the Dial: Find the number on the dial that matches the needle position. This is your key to unlocking correct exposure.
- Reading Aperture and Shutter Speed Combinations: Once aligned, the dial will display various combinations of aperture (f-stops) and shutter speeds that will provide the correct exposure for your chosen film speed.
- Considering Light Conditions: Different light conditions will affect your readings. Bright sunlight will require a shorter exposure or smaller aperture than a cloudy day.
Applying Your Readings: Setting Your Camera
The final step is translating the Weston WX-7’s readings into camera settings.
Matching Meter Readings to Camera Settings
Choose an aperture and shutter speed combination from the dial that suits your artistic vision and the demands of the scene.
- Depth of Field: If you want a shallow depth of field (blurred background), select a wider aperture (smaller f-number, like f/2.8). For greater depth of field (everything in focus), choose a smaller aperture (larger f-number, like f/16).
- Motion Blur: If you want to freeze motion, select a faster shutter speed (like 1/500th of a second). To intentionally blur motion, use a slower shutter speed (like 1/30th of a second or slower).
- Considering Reciprocity Failure: For long exposures (typically longer than 1 second), film may exhibit reciprocity failure, where it becomes less sensitive to light. This means you’ll need to increase the exposure time beyond what the meter suggests. Consult your film’s datasheet for reciprocity compensation guidelines.
Double-Checking Your Settings
Before taking the picture, double-check all your camera settings: aperture, shutter speed, and focus. A quick glance at the Weston WX-7 and a review of the light conditions can prevent costly mistakes.
Frequently Asked Questions (FAQs)
Here are some common questions users ask about the Weston WX-7.
FAQ 1: How accurate is the Weston WX-7 compared to modern meters?
The accuracy of a Weston WX-7 heavily depends on the condition of its selenium cell. A well-maintained WX-7 can be surprisingly accurate, often within 1-2 stops of a modern meter. However, selenium cells degrade over time, so comparing readings with a known accurate meter is always advisable. If the cell is heavily degraded, accuracy will be compromised.
FAQ 2: My Weston WX-7 doesn’t seem to be working. What should I do?
First, ensure the meter is exposed to sufficient light. Selenium cells require a certain level of light to generate a reading. If there’s no movement in bright sunlight, the selenium cell might be dead. Consider getting it professionally checked, although repair is often not cost-effective. Cleaning the cell very gently with a dry, soft cloth might help, but do so at your own risk.
FAQ 3: Can I use a Weston WX-7 for slide film?
While possible, using a WX-7 with slide film (known for its narrow exposure latitude) requires meticulous attention to detail. Slide film demands very accurate exposure. Bracket your shots (taking multiple shots at slightly different exposures) to increase your chances of getting a perfectly exposed image. Incident metering is highly recommended in this case.
FAQ 4: What does the “L” and “H” on the dial mean?
The “L” and “H” refer to Low and High light scales. The WX-7 has a sliding door that covers part of the selenium cell. This door reduces the amount of light that reaches the cell, allowing for more accurate readings in bright sunlight. Using the “L” setting in bright light, or the “H” setting in dim light, can lead to inaccurate readings.
FAQ 5: How do I compensate for backlight with a Weston WX-7?
Backlight can fool the reflected light meter, leading to underexposed subjects. To compensate, either move closer to the subject to take a reading, or use your hand to block the direct backlight from reaching the meter. Then, open the aperture by 1-2 stops from the reading. Alternatively, use incident metering if available.
FAQ 6: Can I use a Weston WX-7 for macro photography?
While you can use a WX-7 for macro photography, it’s often more challenging due to the close proximity and potential for the meter to cast a shadow. Consider using a handheld incident light meter for more accurate readings, or carefully position the WX-7 to avoid shadows. TTL (Through-The-Lens) metering in modern cameras are usually more accurate for this application.
FAQ 7: How do I store my Weston WX-7 when not in use?
Store your WX-7 in a cool, dry place away from direct sunlight. This will help prolong the life of the selenium cell. A case is ideal.
FAQ 8: What are common issues that affect the accuracy of a Weston WX-7?
Besides a degraded selenium cell, dirt, dust, and corrosion can affect the meter’s accuracy. Ensure the lens and the selenium cell are clean. Mechanical issues in the galvanometer can also cause inaccuracies.
FAQ 9: How can I test the accuracy of my Weston WX-7?
The best way is to compare its readings with a known accurate digital light meter or a camera with reliable TTL metering in various lighting conditions. If the readings are consistently off, the meter may require calibration (if possible) or replacement.
FAQ 10: Are there any accessories for the Weston WX-7?
Some models came with accessories like incident light diffusers, carrying cases, and neck straps. These are often difficult to find, but can enhance the meter’s functionality.
FAQ 11: Can I use the Weston WX-7 with digital cameras?
While primarily designed for film cameras, you can use the WX-7 to get a light reading for your digital camera. Just use the meter to find an appropriate aperture and shutter speed for a given ISO, and then manually set those parameters on your digital camera. Use histogram review on your digital camera to refine your exposure.
FAQ 12: Where can I find more information about the Weston WX-7?
Online forums dedicated to vintage cameras and photography are excellent resources. Search for “Weston WX-7” on sites like Photo.net or APUG (now Photrio). You may also find manuals and user guides online, but be cautious about the source’s credibility.