AstroTourist
08-02-2010, 09:43 PM
I have recently returned from a trip to East Africa which included observing the annular solar eclipse from the summit of Mount Kenya so I thought I would tell the story and post some images.
Mount Kenya was close to the centerline of the path of the annular eclipse of 15th January - Path details are here (http://eclipse.gsfc.nasa.gov/SEmono/ASE2010/ASE2010.html). I joined a 6 day trek to be on the Point Lenana summit of Mt Kenya (elevation 4,985m) on the day of the eclipse. It was part of an organized group with people mostly from the UK. It was a 70km trek to include 1 day acclimatization, three and half days to climb the mountain and one and a half days to come down.
Mt Kenya is an ancient volcano whose slopes are quite eroded leaving several dramatic peaks. Although it is very close to the equator, at about 5,000m it is high enough to receive snow and has an amazing 11 glaciers.
There was cloud and at times rain and snow on the upper slopes of the mountain during the three days of climbing before the summit (and the eclipse) day. Summit day was a 2AM start to reach the top in time to watch the sun rise. On that early morning trek, the night sky was brilliantly clear and very dark with of course, no moon.
Sunrise from the summit at 06:30 was simply stunning with the sun rising on a very distant horizon, through a surrounding cloud layer that appeared to have a top level at about 3,000m. First contact for the eclipse was at 07:07 and start of the 8 and a half minutes of annularity at 08:27. The sky above remained completely cloud free and crystal clear after the sunrise and I was able to observe the eclipse through amazingly clear skies. The clarity was like the view from an aircraft without the intervening window and aircraft movement. The ”thumb test” – holding a thumb on outstretched arm to hide the sun - showed blue sky up to very close to the sun showing that there was very little dispersion from material in the air.
About 50 people were at the summit that day with perhaps half that there especially for the eclipse, many of those being first timers. It was an incredible location to experience an eclipse, only 17km from the equator, at -3 deg C (plus significant wind chill) surrounded by the peaks and glaciers of Mt Kenya. Summit day was exhausting, with a total 21km trek, which included an 800m vertical ascent to the summit, and 1,700m descent after the eclipse. Climbing at almost 5,000m is very slow and tiring – one step at a time – at least one breath in & out per step. But it was absolutely worth the effort. The sunrise and eclipse from the summit were an absolutely unforgettable experience.
It was obvious from the view from the summit that there was cloud over much of Kenya at eclipse time especially to the east, and I understand that the eclipse was mostly not seen from Nairobi.
I tried three aspects of photography.
In the first I wanted to capture the eclipse in the surroundings of the mountaintop. I used a wide angle lens for a view from the mountain with the sun included. So that the sun was not overexposed, I hand held a filter in front of the sun. The clarity of the atmosphere is obvious in the image. I had made up a fairly large filter thinking that I may have had to account for greater dispersion, but it was not necessary. See Image 1. Image details are: Canon 450D with 18-55mm lens @ 18mm, 1/350th sec, f9.5, ISO 200; with a ND 3.8 filter hand held in front of the sun.
In the second I wanted to do a typical series of partial – annular – partial phases with a telephoto lens. The initial partial phases went well, however I put the lens and filter down to change to the wide angle lens and when I went to replace them couldn’t find the filter. I found it later (too late) wedged down in the rocks blown there by the wind. So I missed imaging the annular phase. Image 2 is a composite set of 6 images. The first 5 are images from the camera during the partial phases. The sixth (annular phase) is a composite made up from images 1 and 5 to show how the annular phase would have looked. Image 1 to 5 details are Canon 450D with Tamron 28 - 300mm lens @ 300mm (cropped), 1/750th sec f9.5 ISO 200 with a ND 5 solar filter.
For the third, I had made up a Tee shirt especially for the occasion. Have a look at Image 3 and see if you can see what I was doing. It should be clearer in the insert. If you have worked it out and want to check (or if you can’t see it and want to find out) checkout the Solar Eclipse Picture Of the Day (SEPOD) for 24th January http://sepod.wikispaces.com/2010Jan24 (http://sepod.wikispaces.com/2010Jan24) for an explanation. I had a lot of fun with that, and I think that is obvious from the photo.
Rgds,
Terry
Mount Kenya was close to the centerline of the path of the annular eclipse of 15th January - Path details are here (http://eclipse.gsfc.nasa.gov/SEmono/ASE2010/ASE2010.html). I joined a 6 day trek to be on the Point Lenana summit of Mt Kenya (elevation 4,985m) on the day of the eclipse. It was part of an organized group with people mostly from the UK. It was a 70km trek to include 1 day acclimatization, three and half days to climb the mountain and one and a half days to come down.
Mt Kenya is an ancient volcano whose slopes are quite eroded leaving several dramatic peaks. Although it is very close to the equator, at about 5,000m it is high enough to receive snow and has an amazing 11 glaciers.
There was cloud and at times rain and snow on the upper slopes of the mountain during the three days of climbing before the summit (and the eclipse) day. Summit day was a 2AM start to reach the top in time to watch the sun rise. On that early morning trek, the night sky was brilliantly clear and very dark with of course, no moon.
Sunrise from the summit at 06:30 was simply stunning with the sun rising on a very distant horizon, through a surrounding cloud layer that appeared to have a top level at about 3,000m. First contact for the eclipse was at 07:07 and start of the 8 and a half minutes of annularity at 08:27. The sky above remained completely cloud free and crystal clear after the sunrise and I was able to observe the eclipse through amazingly clear skies. The clarity was like the view from an aircraft without the intervening window and aircraft movement. The ”thumb test” – holding a thumb on outstretched arm to hide the sun - showed blue sky up to very close to the sun showing that there was very little dispersion from material in the air.
About 50 people were at the summit that day with perhaps half that there especially for the eclipse, many of those being first timers. It was an incredible location to experience an eclipse, only 17km from the equator, at -3 deg C (plus significant wind chill) surrounded by the peaks and glaciers of Mt Kenya. Summit day was exhausting, with a total 21km trek, which included an 800m vertical ascent to the summit, and 1,700m descent after the eclipse. Climbing at almost 5,000m is very slow and tiring – one step at a time – at least one breath in & out per step. But it was absolutely worth the effort. The sunrise and eclipse from the summit were an absolutely unforgettable experience.
It was obvious from the view from the summit that there was cloud over much of Kenya at eclipse time especially to the east, and I understand that the eclipse was mostly not seen from Nairobi.
I tried three aspects of photography.
In the first I wanted to capture the eclipse in the surroundings of the mountaintop. I used a wide angle lens for a view from the mountain with the sun included. So that the sun was not overexposed, I hand held a filter in front of the sun. The clarity of the atmosphere is obvious in the image. I had made up a fairly large filter thinking that I may have had to account for greater dispersion, but it was not necessary. See Image 1. Image details are: Canon 450D with 18-55mm lens @ 18mm, 1/350th sec, f9.5, ISO 200; with a ND 3.8 filter hand held in front of the sun.
In the second I wanted to do a typical series of partial – annular – partial phases with a telephoto lens. The initial partial phases went well, however I put the lens and filter down to change to the wide angle lens and when I went to replace them couldn’t find the filter. I found it later (too late) wedged down in the rocks blown there by the wind. So I missed imaging the annular phase. Image 2 is a composite set of 6 images. The first 5 are images from the camera during the partial phases. The sixth (annular phase) is a composite made up from images 1 and 5 to show how the annular phase would have looked. Image 1 to 5 details are Canon 450D with Tamron 28 - 300mm lens @ 300mm (cropped), 1/750th sec f9.5 ISO 200 with a ND 5 solar filter.
For the third, I had made up a Tee shirt especially for the occasion. Have a look at Image 3 and see if you can see what I was doing. It should be clearer in the insert. If you have worked it out and want to check (or if you can’t see it and want to find out) checkout the Solar Eclipse Picture Of the Day (SEPOD) for 24th January http://sepod.wikispaces.com/2010Jan24 (http://sepod.wikispaces.com/2010Jan24) for an explanation. I had a lot of fun with that, and I think that is obvious from the photo.
Rgds,
Terry