At least three club members acted on the message about the lunar eclipse that was sent out recently.
First, Yuan Liu and Dennis Glanzman used the information in the article and had great fun shooting the eclipse. Here is one of the images that resulted. Yuan provided this background information relating to the photo. The Chinese characters in the picture mean Lunar Eclipse. The literal translation is:
月 = n. Moon; 全 = adj. The entire or the whole;
蚀 = v. Being eaten. An ancient Chinese legend states that the eclipse is caused by a nasty dog who lives in the sky and eats the moon. The dog has a weakness though – she is afraid of sound. So, during an eclipse, the people will bang drums and light fire crackers to scare the dog so that she will spit out the moon. I also read that medieval Europeans had a similar legend, except that the eater who devours the moon during an eclipse was a dragon, not a dog.
There is a star in the picture as well, which according to Dennis’ astrophysicist brother Tom, is Saturn. The following is the information that Tom provided. According to NASA, “During the eclipse, the Moon will be in Leo. Saturn and bright star Regulus are only 3 degrees east and west, respectively, of the Moon. Gemini, Orion, Taurus, and other winter constellations will occupy the southern and western sky for North American eclipse viewers.” http://sunearth.gsfc.nasa.gov/eclipse/LEmono/TLE2008Feb21/TLE2008Feb21.html
The following website has a collection of images of the February 20th lunar eclipse from other photographers: http://www.rrstar.com/homepage/x1300265491?pop=true
Secondly, Alvin Sachs relayed some comments on the article from a former speaker for the club and a semi-professional photographer, Mark van Bergh. Mark notes that if he uses the sunny 16 rule when photographing the moon, his images are underexposed, so he recommends opening up 1 or 2 stops and/or using a spot meter. The article (see http://www.nyip.com/ezine/outdoors/eclipse.html) did stress bracketing, which would also take care of this problem. He also thought that the article did not emphasize the fact that there will be blurring when using long shutter speeds to photograph the eclipse.
Comments from Mark van Bergh Regarding the Lunar Eclipse Article
“While the article had lots of information, I thought some of it was wrong or not as helpful as it could have been. For example, it says to photograph a full moon using the sunny 16 rule, which I have found results in underexposure of the moon. While the theory may be OK (i.e., the moon is in full sunlight), it is not like photographing a subject on earth in full sunlight. First, the moon is about 250,000 miles distant so the reflected light is dissipated somewhat over that distance. Second, the light has to go through the entirety of the earth’s atmosphere which further weakens it. I don’t recall precisely what exposure I have found works (I generally use a spot meter – more on that in a second), but recall that it is several stops more than sunny-16.
Second, the article makes no mention of using a camera’s spot meter, if it has one, particularly when shooting with a telephoto lens. If a long enough lens is used, and the spot meter has a sufficiently narrow angle, then the spot will cover the moon and you can get an accurate meter reading (though you will want to open up about 1 stop, give or take a 1/2 stop, because of its “whiteness” – except during the eclipse).
With respect to shooting during the eclipse, the article barely mentions a problem that will result because of the longer shutter speeds needed when the moon is in shadow – the earth’s rotation and the appearance of movement in the moon, and thus blurring of the subject, that it creates. The article makes one reference to this, but does not really highlight it. It does indicate that an exposure of longer than about 1-2 seconds can cause a blurring effect. Well, the amount of blurring will depend on the focal length of the lens used – the longer the focal length the greater the amount of blur and the shorter the exposure needed to avoid it. I don’t know what the specific formula is so I can’t really be more helpful here. Those are just a few of the problems I saw.”
Dick Sprott adds that with a long focal length lens ¼ second is long enough to produce a noticeable change in the shape of the moon
