The imaging basics: GENERAL RECORDING
More information will give your images more scientific value
Annotating your image in a layer-based editor ensures the salient details are recorded and displayed for all to see. Include the date, time (UT) and location, preferably with additional information about equipment and exposure.
Imaging auroral or noctilucent cloud displays requires similar disciplines. These phenomena are best suited for wide- or mid-field lenses attached to a DSLR mounted on a tripod. Telephoto zoom lenses can also be used to focus in on fine detail during bright displays. More detailed time-lapse images are very useful for determining exactly how structures change with time. If you record a timelapse sequence, make sure to add the start time, frame interval and end time on it.
At a bare minimum, it’s essential to note the location, date and time on your images to add value to them, and your camera’s date and time should be set against the most accurate source possible. Dates should be recorded ideally as a double date: for example June 12/13 would refer to the evening of 12 June into the morning of 13 June. The time you took the photo should be recorded to the nearest minute and noted in UT. Locations can be identified by latitude and longitude, which you can find online from resources such as Google Earth or a good old paper map. Alternatively, the name of the nearest town or city is better than nothing.
It is useful to attempt to image at least two background stars at the same time as a display. For example, during NLC season in the UK, the bright star Capella (Alpha (_) Aurigae) is often conveniently placed behind displays along with the dimmer, medium bright stars that form Auriga. If these are recorded in a photo, the altitude and azimuth of display features can be determined.
Camera exposures don’t always record the brightness of features as they would have appeared to the naked eye, so it’s useful to include a physical report of the brightness you actually saw.
As always, write all the details directly onto photographs using a graphics editing program like GIMP. Annotating images in this way ensures that all the relevant information stays with the image and is immediately available to future viewers.