The best fixer for black and white film is arguably sodium thiosulfate-based fixers, often referred to as “hypo,” due to their effectiveness, economy, and long history of reliable performance. However, specific needs like archival permanence, speed, or environmental considerations may lead photographers to prefer alternative fixers, such as ammonium thiosulfate-based rapid fixers.
Understanding the Role of Fixer
Fixer is an essential chemical in the black and white film development process. Its primary function is to remove undeveloped silver halide crystals from the film emulsion, rendering the image permanent and preventing it from being further affected by light. Without proper fixing, the image would eventually darken and become completely black. Selecting the right fixer and using it correctly are crucial for achieving optimal image quality and archival stability.
The Two Main Types of Fixer
There are two main types of fixer used in black and white film photography:
-
Sodium Thiosulfate-Based Fixers (Hypo): These are the traditional, widely used fixers. They are known for their reliability, affordability, and ability to produce images with excellent archival properties when used correctly.
-
Ammonium Thiosulfate-Based Fixers (Rapid Fixers): These fixers work much faster than sodium thiosulfate. They are preferred by photographers who prioritize speed and convenience. However, they require more careful washing to remove all traces of the fixer from the film, as residual ammonium thiosulfate can lead to image degradation over time.
Factors to Consider When Choosing a Fixer
Choosing the right fixer involves considering several factors:
-
Archival Permanence: This is paramount for photographers who want their images to last for generations. Sodium thiosulfate-based fixers generally offer superior archival properties when followed by proper washing.
-
Speed: If you’re working on a tight schedule or need to process a large volume of film, rapid fixers can significantly reduce development time.
-
Film Type: Some films may be more sensitive to certain fixer types. Consult the film manufacturer’s recommendations.
-
Cost: Sodium thiosulfate-based fixers are generally more economical.
-
Environmental Impact: While both types require proper disposal, some environmentally conscious photographers might consider options that minimize their footprint.
FAQ: Deep Dive into Film Fixing
Here are some frequently asked questions to provide a more comprehensive understanding of black and white film fixer:
FAQ 1: What exactly does “fixing” do to the film?
Fixing dissolves the undeveloped silver halide crystals that remain on the film after development. These crystals are light-sensitive; if they aren’t removed, they will continue to darken over time, eventually ruining the image. Fixing stabilizes the image by removing these light-sensitive components, making it permanent.
FAQ 2: How can I tell if my fixer is exhausted?
Several tests can determine if your fixer is exhausted. One simple method is the “clearing time test.” Drop a small piece of undeveloped film into the fixer. Time how long it takes for the milky appearance of the film to disappear (clearing time). If the clearing time is more than twice the recommended time (typically 2-4 minutes for fresh fixer), the fixer is exhausted and should be replaced. Another indicator is a change in color or the presence of sludge at the bottom of the container.
FAQ 3: Is it possible to over-fix film?
Yes, it is possible to over-fix film, although the effects are usually subtle. Prolonged fixing can leach silver from the image, leading to a slight reduction in density and contrast. It can also make the film more susceptible to damage during washing and drying. Always adhere to the recommended fixing time provided by the film and fixer manufacturers.
FAQ 4: Can I reuse fixer? If so, how many times?
Yes, fixer can be reused, but its capacity is limited. The number of rolls you can fix with a given volume of fixer depends on the type of fixer, the size of the film, and the amount of silver halide present. A general rule is to discard the fixer after it has fixed a certain number of rolls per liter/gallon, as specified by the manufacturer (usually around 24-36 rolls of 35mm per gallon). Keep track of how many rolls you’ve fixed to avoid using exhausted fixer.
FAQ 5: What’s the proper way to dispose of used fixer?
Used fixer contains silver, which is a valuable and potentially harmful pollutant. Never pour fixer down the drain. The best way to dispose of it is to recover the silver using a silver recovery system. These systems use various methods to extract the silver from the fixer, allowing you to recycle the silver and dispose of the remaining solution more safely. Alternatively, you can contact a hazardous waste disposal facility for proper disposal.
FAQ 6: What is the recommended fixing time for black and white film?
The recommended fixing time varies depending on the type of fixer and the film. Always consult the manufacturer’s instructions for both the film and the fixer. Generally, sodium thiosulfate-based fixers require a longer fixing time (5-10 minutes) than ammonium thiosulfate-based rapid fixers (1-3 minutes).
FAQ 7: What role does a hardener play in fixer?
Some fixers contain a hardener, typically potassium alum. The hardener helps to harden the film emulsion, making it less susceptible to scratches and damage during washing and drying. This is particularly useful for films with a softer emulsion. However, hardeners can also make archival washing more difficult. Consider whether your film type benefits from hardening or if you prioritize maximum archival permanence.
FAQ 8: What’s the difference between a one-bath fixer and a two-bath fixer?
A one-bath fixer contains both the fixing agent (sodium or ammonium thiosulfate) and sometimes a hardener. A two-bath fixer uses two separate baths of fixer. The first bath removes most of the silver halide, while the second bath ensures complete fixing. Two-bath fixing is more efficient and helps to prolong the life of the fixer, and is especially useful if you are consistently using a large number of negatives.
FAQ 9: Is it safe to use different brands of fixer and developer together?
Generally, yes, it is safe to use different brands of fixer and developer together. However, it’s crucial to follow the manufacturer’s instructions for both products. Ensure that the pH levels are compatible to avoid any unexpected chemical reactions. It’s also a good idea to do a small test run to see if any problems arise before processing a large batch of film.
FAQ 10: How important is proper washing after fixing?
Proper washing is absolutely critical for archival permanence. Fixer left on the film will eventually cause the image to fade and deteriorate. Thorough washing removes all traces of fixer from the emulsion. Use a good film washing method, such as the Ilford Method (filling and emptying the tank several times with fresh water) or a film washer specifically designed for this purpose.
FAQ 11: What’s the shelf life of black and white film fixer?
Unmixed, dry fixer has a long shelf life, typically several years if stored in a cool, dry place. Once mixed with water, the shelf life is significantly shorter, usually several weeks to a few months, depending on storage conditions and usage. Store mixed fixer in tightly sealed containers to minimize oxidation and contamination. Note the date of mixing on the container.
FAQ 12: Can I use fixer for paper development as well as film?
Yes, the same type of fixer can be used for both film and paper, although you might want to use separate batches. Used film fixer can be used for paper, however, do not use fixer already used for paper to then fix film as the chemicals that come off of the paper can damage the film negatives. The fixing time may differ slightly, so always consult the manufacturer’s instructions for both the paper and the fixer.