Choosing a Suitable Film for Meteor Photography

The other major component is the film: today, high sensitive films (ISO 3200/36) with reasonable grain structure (such as the so-called T-grain; T standing for tabular) are available. But it is not primarily a large ISO number which guarantees success with meteor photography. Every emulsion differs from another particularly in its behaviour during long exposures, i.e. when the exposure times exceed a minute or so. Furthermore, the trade names of films vary from country to country and are also subject of change with time, so it is of little use to list all the possible sorts of films presently available. Good examples are Ilford's HP-5 and Fuji's Neopan 1600 (which both can be pushed to ISO 3200/36). However, it is up to the photographer to decide which film to buy: select the fastest film with as fine a grain structure as possible, within your own budget. If you photograph very frequently it is worthwile to buy film in boxes of 30 m length and spool them in cassettes yourself.

Exposure times should be of the order of 10 to 15 minutes for optimal results, but on very dark locations exposure times up to 30 minutes still give reasonable results. Again, you have to make some experiments which show the best values for your observing site. These figures will also depend on the actual conditions, like haze or moonlight. Exposures which lead to a considerable blackening of the background should be avoided. Here, again, it is difficult to give fixed recommendations. Some more information can be found in the IMO's Photographic Handbook.

If a meteor appeared during the exposure, it is advised to finish the exposure very soon in order to avoid later disturbances which may badly affect the image (various accidents may always happen).

Developing your films

Developing your films is easier than many might think. You do not need complex darkroom equipment -- a small developer tank will do. Furthermore, you can influence the result (pushing etc.), while professional labs might let you know that 'there is nothing on the film'.

Instructions for films give sufficient information for various developing procedures. In any case it is best to choose a developer which makes use of the film's sensitivity. A fine grain developer does not only have a good influence on the grain size, it also produces a rather low-contrast image which allows to transform a very wide range of brightnesses into different amounts of 'blackening'.

Finally, it is strongly recommended to mark your films unambiguously already during the exposures and to keep a logbook. Otherwise the identification of meteor trails and the determination of the exposures may become hopeless. The essential data to note are the begin and end of the exposure, the times of bright meteors (if seen), and the region of the field of view for identification or search for fainter trails which may be missed during a first inspection of the film. If you do regular photographic work, you will find it useful to have a reference number or designation for each film or meteor negative. If you do not want to store the entire film, it is recommended to keep the negatives showing a meteor AND their neighbouring images in the archive. This may be helpful for possible later analyses.