About the photography
Camera
For photography of optical phenomena, I recommend you to have a manual camera ready all the time at home, and a small compact camera with you all the time. Better is to have the manual camera with you but this is quite bulky and heavy to carry around. Make sure both cameras are loaded with film all the time, and you have a few new rolls of 36 exposures each ready.

Both the manual and the compact camera should have the Bulb setting 'B' for manual shutter control. This is handy in case you have to photograph a halo around the moon, in which case you may need to expose the photo about 10 seconds or so.

Do not buy an APS compact camera, but a 35mm camera.


Camera lenses
Choose a compact camera with a good quality lens on it. Fixed-size lenses are better than zoomlenses, however, some subjects may be very tiny if photographed with a wide angle lens, and the film granulariry will actually cause the photo to be less quality than the same photo if taken with a zoom lens zoomed in to the subject. (I myself decided to buy a compact camera with a zoomlens on it, made by Schneider.)

For the manual camera, you should have a wide variety of lenses available. Do not use zoomlenses with the manual camera, as the camera system is composed of a body and separate lenses, anyway. Obtain the following lenses (I assume you have a standard 35mm manual camera like the good old Praktica):

16 mm fish-eye (or 180 deg. angle adapter): Necessary for capturing a halo display with all arcs appearing on the same photo. This is useful for analysis of the photos later on. If you only make normal-view photos of all halos, parhelia and arcs, it is not clear which arcs were visible at the same moment. Also, a fish-eye lens is nice to have if you want to capture the all-sky view of a sunset with twilight arc in the west and the earth's shadow in the east, for example.

Note: if you don't buy a fisheye standalone lens but a fisheye converter, you will save much money, and you can mount the adapter to every other type of lens, so you can make other lens systems, for example, a lens system with 100 deg. view. Really handy in case you need to photograph the 46 deg. halo in its entirety, for example!
To give you an idea of the price of a fisheye converter: I bought mine second-hand, one (a true 180 deg. fisheye converter) for and the other (a semi-fisheye converter with 150 deg. view) for .

28 mm wide-angle lens: This lens is the most important lens to have. Keep this one on the camera all the time, when not using it. When an optical phenomenon suddenly occurs, you can take action immediately, without first having to change lenses (Prakticas have lenses that must be screwed on and off the camera, really awesome work if you're in a hurry!)

50 mm standard lens: This is nice to have the smaller phenomena larger in view, like heiligenschein, antisolar rays, coronas and glories, to name a few.

135 mm telelens: Necessary to photograph phenomena with even smaller extend, like a localized iridescent cloud, a corona aureole, a roadway mirage, etc.

1000 mm telelens: Necessary to photograph the sun showing a green rim, green segment, green flash, Chinese-lantern-effect, and for photographing all sorts of horizon mirages.


Filters
The third thing you may want to have is a filter. There are two kinds of filters interesting for color photography of atmospheric optical phenomena: the UV filter and the polarizing filter. The UV filter is - I think - not that necessary, as most modern lenses have UV coatings of their own, and film nowadays is much less sensitive to UV light than in earlier days.

However, the polarizing filter is very useful. Light reflected and refracted by ice crystals and water droplets becomes linearly polarized, that is, the light waves have a certain transversal, linear orientation. The filter only passes light of a certain linear polarization direction, and by rotating the filter around for 90 degrees, the light wave will either be fully transmitted, not at all transmitted, or partially.

In effect, you can play with the intensity of a phenomenon like a parhelion by simply rotating the filter on the camera lens, and go for maximum contrast of the effect.

Secondly, the blue sky is also linearly polarized, most at 90 degrees away from the sun, and the sky light can be drastically reduced in this direction by adjusting the filter rotation.

There are two types of polarizing filters: linear and circular. The circular filter is better to have, especially when using a camera with an autofocus lens, or a zoomlens. It is also more expensive than a linear filter. However, for this purpose, the filters have the same effect - increasing contrast.