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Introduction
Astronomy photography is much different than weather photography or lightning photography. But it is as much fun, and it can yield great photos of all sorts of astronomy phenomena.
For space photography you will need the following things: camera, lenses (ranging from 28mm to 1000mm), tripod, lockable cable release, film of 200 ISO and 800 or 1600 ISO, and a star tracking device. Descriptions of these items follows below.
Camera
Use a manual or (semi)automatic SLR camera on manual mode, like the Praktica, Nikon, Canon, etc. It may be second hand but make sure it is reliable. Especially if you're new to photography, a standard 35mm camera body will be best. For professional photography, a medium format camera will be better, or even a plate camera like the 4"x5". This is especially true because of the large ISO number of the film to use, this is a low resolution film compared to 50 or 100 ISO.
Lenses
I assume with respect to the mentioned lens sizes that you own a 35 mm camera. In that case, the following lenses are most suitable for space photography:
28 mm wide-angle lens: you use this for capturing things like the aurora Borealis / Australis, airglow, large constellations, the milky way, meteor photography, zodiacal light, etc. All subjects that may cover a large part of the sky.
50 mm standard lens: used for photographing the smaller constellations, gegenschein, etc.
135 to 200 mm telelens: for photography of large nebulae like the Andromeda nebula.
600 mm telelens: for solar eclipses.
1000 mm telelens: Used for photography of the sun, the moon, solar and lunar eclipses, star clusters like Pleiades, etc.
Tripod
This is necessary for all photography, if a tracking system is not used due to short exposure times (see also the tracking system specifications). It is imperitive to use a very heavy and strong tripod, especially when using a super telelens.
Lockable cable release
During the exposure there may not be any movement of the camera, especially not when using super telelenses like a 1000 mm lens. The camera is operated on Bulb mode 'B', and as soon as the shutter is opened, the cable release is locked and you move away or stand still as the exposure is being made. You may want to buy a very long cable release like I did, of 1 meter (3.2 ft) in length.
Film
Type: Use slide film, this is somewhat sharper and has more contrast than negative film. There are a number of slide films available, well-suited for space photography. I can't help you much with exact film types, as I myself have just started the hobby.
Speed: If you have a tracking device, you can in principle use any film in the range of 200 - 1600 ISO. However, on the one hand it is better to use fast films, because long exposure times will shift the color balance of a film (i.e. 4 minutes on 200 ISO at F/8 will not give the same result as 8 minutes on 200 ISO at F/11, altough the quantity of light would in both cases be the same). Thus, when photographing things like nebulae, stars, meteors and comets, use 800 to 3200 ISO film.
Brand: I am inclined to think that Fuji is probably most suited for photography of celestial objects, if choosing color photography. But I don't know for sure. But I like Fuji better than other brands, if it comes to weather, lightning and space photography.
Tracking system
When you want to make long exposures (some exposures may take over 1 hour), a tracking system is needed. This is necessary for photography of subjects other than the aurora, zodiacal light and airglow. Basically, every subject that moves with the stars and is thus not earth-bound. (However, the zodiacal light is one exception to this, but it is best too photograph this without tracking the stars because else, you would end up with a moved horizon, and since the zodiacal light is just over the horizon, this can ruin your photo.)
The following table lists about the maximal exposure times for a certain lens size, before the effect of earth rotation shows up:
LENS SIZE (mm) MAXIMAL EXPOSURE TIME (sec)
28 60
50 25
200 10
600 4
1000 2
Note: This table is according to my own experience, and is therefore just a rough guideline.
Any higher exposure times you want to use than those I mentioned, will definitely need a tracking system to follow star progress. If you're handy with machining wood and metal, you can construct your own tracking system, using the mechanics of an analog, low-cost, alarm clock or something, and with some axes and clogs you'll end up with a fairly good tracking device. If possible, take into account the length of one astronomical day, being about 23h 56m instead of 24 hours (my father always says: get the cheapest and worst-quality alarm clock available - if you're lucky this may run as much as 4 minutes behind each day and you have a perfect tracking motor!)
There exist two different types of tracking devices: azimuthal and polar-axis mounting. For your purpose, a polar axis mount is the only interesting, since you have only one rotation axis to drive and not two simultaneuously, as with the azimuthal mount. The polar tracking device consists of a rotation axis pointing to the north pole (or south pole) celestial point of rotation (in the north well marked by Polaris). This axis sets the right ascention. The second axis remains arbitrary and sets the declination. During star photography, the right ascension axis is rotated at a rate of 1 round per 23h 56m., while the declination axis is fixed to the declination of the subject to be photographed.
Make sure you build a heavy and bulky construction if you mostly photograph at home. This reduces possible tremor (caused by wind, and by walking persons, etc.).
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Photographing different phenomena
Total solar eclipse
This is probably the most exciting of all nature phenomena. I have one important tip, if you are going to witness a solar eclipse for the first time. Enjoy the sight and look much in the few minutes it lasts. Photograph little or not at all. Many people (including me) want to make many photographs the first time they get to see an eclipse. Do not. When it happens, you are so thrilled and excited and bewildered that you can't think anyway. It is a totally strange experience, and whatever you would imagine beforehand what it will look like and be like, it is totally different than you had expected. The sun and moon look static in the sky, but the last 20 seconds before the total eclipse, things happen very quickly. The sky noticeably darkens in the west - that is, you actually see it darken second after second. You may see the lunar shadow race towards you over a distant mountain or cloud deck. When the sun finally disappears, the sight is so brilliant and beautiful and strange that you forget everything around you.
The site of Fred Espenak has much information on it, including a solar eclipse exposure table which relates the Q-factor (brightness) and f-stop / ISO number with exposure time. I did my solar eclipse photography according to that table and the result was perfect.
Decide beforehand exactly what photos you will take, with what settings. Write this clearly and big on a piece of paper. When the eclipse is due, set all equipment ready at hand, choose just one lens and camera for the total eclipse photography, and tape the paper with exposure settings to the tripod. Have a small lamp ready, also fastened to the tripod, because you may not be able to read anything during the total eclipse. Just follow the table and photograph. Don't think (you can't, due to adrenaline, anyway) but just follow the list of exposures you made. Make sure you know your camera, because you will have to adjust the exposure time knob and aperture ring in total darkness. Don't forget to check in the camera view for each photo, to correct for the progress of the sun along the sky. And make sure you have the focus to infinity. Last: don't forget to take the ND4 or ND5 filter off the lens, which you may have used if you photographed the solar disk in partial eclipse.
I urge you not to spend more than 1/2 of the time the eclipse lasts to your camera equipment. After that, just watch and enjoy the sight.
Total or partial lunar eclipse
A lunar eclipse is drastically different than a solar eclipse. However, it still is exciting, because you will not know for sure beforehand which color the moon will become - this depends on the state of the earth's atmosphere. If there are many clouds along the earth's horizon as seen from the moon, sunlight reddened by the atmosphere will mostly be blocked, and the moon will get dark. If there are few clouds, the moon will get a nice bright rusty or orange color. If there has been volcanic activity and there are many clouds, the moon might be hard to see at all or invisible. Your photography obviously depends on the type of lunar eclipse. There exists a so called 'L' scale for lunar brightness, ranging from L=0 for invisible to L=4 for bright orange. The site of Fred Espenak contains more information, and the correct exposure table for eclipse photography.
Unlike with a total solar eclipse, photographing a lunar eclipse is very easy and relaxing. However, during totality, the moon will be too dark to photograph by using a fixed tripod (assuming you have a slow film) - even if the moon is very bright orange. You will need a tracking device for that. The partial phases can be photographed with ease using a tripod, exposure times ranging from 1/500 to 1 second at F/10 and 100 ISO film. It is a good idea to bracket each photo, that is, to make two extra photos with each photo you make, one with one f-stop higher, and one with one stop lower. Photograph the moon about once per 15 minutes, and note down the exposure times and aperture settings while taking photos. You'll have about 1 hour during the partial eclipse, that is, while the moon is moving from the earth's penumbral shadow to its umbral shadow; you have about 1 1/2 hour (maximal, if the moon crosses the shadow in the centre) during totality, and again aobut 1 hour for the second partial phase. The moon entering and exiting the penumbral shadow, you will hardly notice.
Moon photography
This can best be done while the moon is crescent or first quarter. For a full moon, you can obtain good photographs which nicely show the moon's mares (seas), while at first quarter, the craters and mountains are much detailed because of the light grazing the moon's surface at that part. The crescent moon can be photographed to show the greyish illumination of the dark part, due to full earth. Quick settings for the camera: use a 1000 mm telelens or similar, ISO 100 film, and expose (at F/10 aperture) 1/60 second for full moon; 1/15 second for first or last quarter moon; 1/4 second for crescent moon (for moon detail); 10 to 20 seconds for the ash grey light. For the latter, use a tracking device, as exposure times longer than about 2 seconds with 1000 mm lens will show progress of the moon, due to earth rotation. Make sure you bracket each exposure.
Photography of the sun / sunspots
Use a 1000 mm or 2000 mm telelens, and an ND5 filter: a neutral density filter, factor 5. This reads 10 log F = 5 thus follows F = 100,000 with F the filter factor - the ND5 filter will attenuate the light by a factor of 100,000. With this, the sun can be photographed (when high in the clear sky) at F/10, 100 ISO, 1/250 second or so. Bracket your exposures by 2 or 3 stops.
Be very careful with the filter, avoid looking through the camera too much. Some filters are not very reliable, and even though the sun may not look bright to the eyes through the camera view, very intense infrared light might still be transmitted. Since you have no pain sensors in the retina of the eyes, you will not feel that there is something wrong, until after about 15 minutes, when it is too late. So be VERY careful. Best thing to do is to view the solar disk indirectly, using a small aperture hole in a piece of board, and projecting this on a sheet of white paper. You then get an image of the sun on the paper, which is perfectly safe to look at.
General notes
It is very helpful if you learn about meteorology also, if you want to do photography of celestial objects. It helps to know what kind of weather front is passing over, if clear skies are to be expected or not. For instance, a cold front usually doesn't take long to pass (in Holland, NW Europe, that is) and the air behind a cold front is very dry, cold and clear. Not much star scintillation, i.e. optimal conditions for space photography. On the other hand, a warm front takes longer to pass, and brings only more cloudiness and haziness. Whereas storms are localized and usually have clear air in between them.
Sleep well, dress warm and drink soup often to keep the hobby interesting.
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