Photographic Tips
Equipment
Any camera with the capability of setting shutter speeds and aperture settings manually will do fine. The ability to use interchangeable lenses will be an advantage for more detailed images of the Moon. For the darker parts of the eclipse, eg. totality you should use a tripod support for best results. If you have access to a telescope you can try capturing the event using prime focus techniques through the telescope optics.
Film
Film is very much a personal choice. Today's emulsions are very fine-grained and detailed in spite of their rated speeds. Don't be shy to use ISO 400 or even ISO 800 film. Given the speed of the optics you are using you may have to opt for a higher speed film anyway. For astronomical subjects using negative film I've always been a great fan of Fuji Super G 800, you'll need to go to a camera specialty store for this one. Another good film is the more current and easily obtained film Fuji Superia 400. For slide film I understand the Kodak Ektachrome Professional E200 is an excellent film with good pushing capabilities although at the expense of increased grain.
Technique
The simplest eclipse pictures can be taken with a manual camera and a normal lens, preferably supported by a tripod. For best results use a cable release to minimize vibration. Images taken in this fashion result in a small lunar image. This is why it is preferable to use a telephoto lens to photograph the Moon. For a 35mm camera try a 200mm lens or something close to this, even better a 500mm lens or higher. You may also use teleconvertors to increase magnification, these typically come in 1.4x and 2x strengths. Their downside is they reduce the effective aperture of your optical system. A 1.4x teleconvertor will decrease your effective exposure by 1 stop, a 2x teleconvertor will decrease your effective exposure by 2 stops. Work out your effective aperture of your optical system ahead of time so you don't have to think about it on the night of the eclipse.
Example:
|
Focal Length |
Aperture |
Effective Focal Length
with 2x teleconvertor |
Effective Aperture
with 2x teleconvertor |
|
180mm |
2.8 |
360mm |
5.6 |
|
480mm |
6.8 |
960mm |
13.6 |
To achieve any higher magnification than what is stated above you will have to use a telescope at prime focus. For this your manual camera does need to have the capability of using interchangeable lenses. For prime focus you will use the telescope optics as your interchangeable lens. To attach your camera to your telescope you will need two things a T-adapter that fits your camera and a telescope camera adapter that fits your telescope. The telescope camera adapter is designed to fit in the focusing tube of your telescope and is threaded to accept the T-adapter of your camera. With the magnification involved with telescopic optics it is likely that you will need to use a tracking mount. Preferably the mount should be able to track at lunar speed as opposed to sidereal but if the shutter speeds chosen are shorter than 1 or 2 minutes this is not critical.
Exposure times are the next consideration. The following exposure times are based on a medium speed film and an effective aperture that would be common with a long telephoto and teleconvertor combination. Exposures may vary with your equipment based on ISO speed of film used and effective aperture. The Danjon Lunar Eclipse Luminosity Scale has been included to provide better guesstimates for totality.
|
Exposure Times: based on ISO 400 speed film
|
|
Full Moon |
1/250 second at f/16 |
|
1st Contact |
1/125 second at f/16 see note 1. |
|
2nd Contact |
2 seconds at f/16 see note 2. |
Totality
*see table below |
|
L = 4 :
|
8 seconds at f16 |
| L = 3:
|
30 seconds at f16 |
| L = 2:
|
2 minutes at f16 |
| L = 1:
|
8 minutes at f16 |
|
|
3rd Contact |
2 seconds at f/16 see note 2. |
|
4th Contact |
1/125 second at f/16 see note 1. |
|
* Danjon Lunar Eclipse Luminosity Scale
|
|
L = 1 |
dark eclipse; lunar surface details distinguishable only with difficultly |
|
L = 2 |
deep red or rust coloured eclipse; central part of the umbra dark but outer rim relatively bright |
|
L = 3 |
brick-red eclipse; usually with a brighter (frequently yellow) rim to the umbra |
|
L = 4 |
very bright copper-red or orange eclipse, with a bluish, very bright umbral rim |
If you are using a digital camera the same techniques apply. Use ISO settings of 400 or 800 and the longest telephoto setting you have.
Note 1. 1st and 4th contact times given for the partial phases are biased for the light part of the Moon. Remember you are dealing with vastly different exposures between the light and dark parts of the Moon during eclipse. The bias of about 1 stop minus avoids overexposure of the dominant bright area of the Moon.
Note 2. 2nd and 3rd contact times given for the partial phases are biased for the dark part of the Moon. The bias of about 1 stop plus is a good strategy for negative film not quite so good for slides and digital capture given they don't tolerate overexposure well.
The exposure times are only recommendations. Remember the cardinal rule about photography ... bracket. Always try exposures plus and minus your chosen exposure. This gives you a better chance at getting usable results. Let's all hope for clear weather. If you have any questions please send email to David_Lee@telus.net .
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