Expired Films

[rashed]

<p>When shooting 8 years expired films and getting many of the elements turn to be good, like exposure, colors and contrast, what would be the other elements which might turn to be false or not good ?</p>

<p>Few days back I shoot a Fuji 100 ASA color Negative film , yes I did get very nice result but again I noticed sever grain, specially in the sky, could this be one of the elements and bad signs for such an 8 years expired film ?</p>

<p>Thank you and wishing you all of the best.</p>

[Alan Marcus]

<p>Photographic materials are perishables with an expiration date, generally about 2 years from manufacture. Film consists of light sensitive crystals (silver salts) that undergo chemical changes when exposed to light. During processing, the developer is able to recognize exposed crystals and ignore unexposed crystals. <br>

<br>

The problem is these crystals will appear to the developer as exposed if they encounter various chemical fumes or experience naturally occurring background radiation. The same thing happens if film is stored in a warm environment. Thus as film ages, more and more of these crystals will be tripped off by non-light energy. When developed the film will take on an overall darker hue we call this fog. After a time the entire film will be effected and thus unusable.<br>

<br>

In the early stages of ageing, the film gains ISO speed. This is because crystals that need, say 100 photon hits to become exposed have already received the equivalent of say 25 from factors of storage. Thus, they need less light during the camera exposure. A valid technique used to increase ISO is a controlled uniform exposure to light. This is hyper-sensitization. This is also accomplished by deliberate exposure to certain chemicals. Often a super fast film is actually a slower cousin factory hyper- sensitized. <br>

<br>

In the case of color films, they are made in batches and each batch has slight variation in speed and color balance. One key ingredient responsible for changes is gelatin. This is an animal product that varies chemically based on animal feed. The problem is, gelatin has a great impact on final ISO. Over time, the color balance of films will drift based on current gelatin sources.<br>

<br>

Color films are always augmented by test materials used by the labs to assist with process and printer adjustments. Over time, new film batches emerge, this makes it compulsory for a lab to purchase revised materials. Film you have stored for many months/years will no longer be compliant with the test materials in use at the lab. Labs attempting to print older emulsions are disadvantaged. </p>

[randall_pukalo]

Yes, increased grain is the main problem with expired films, especially negative films. The faster the film speed, the worse the problem. Some films, particularly E200 and Kodachrome 200, develop color casts. With E200 it is a red cast, with K200, a magenta cast. Other films, especially slide films, hold up very well past expiration date.