I noticed quite late that we are going to have another Venus - Solar transit in a few days and that is going to be the last Venus transit for almost a century. I have not done any serious solar viewing or photography before this. But the rarity of the event and the equipment I have now wants me to take a shot at it.
It goes without saying that you need a solar filter. Over here in in SL, they are a bit too hard to come by. Previously when I was photographing and viewing the annular solar eclipse in 2010, I used a cut up x-ray film with my Canon S2IS (this method is debated). The problem this time is that I now have a Canon 550D, whose lenses have a much larger aperture and the original x-ray cut ups wouldn't work anymore.
1st attempt: Use a type of coloured cellophane that is available over here as a filter. A single sheet is way too thin so tried stacking up about 10-12 on each other. However it diffuses the light so much that it is barely of any use.
2nd attempt: Center the x-ray piece on the lens and try with that. Well that works when it is fully zoomed out, but as you start zooming in, the sun tends to get in from the sides. So no joy there.
3rd attempt: My dad comes up with this ingenious idea; Cut up a cardboard ring that will cover the area outside the x-ray film. About five minutes later we ended up having a cardboard ring with an aperture of about an inch (with a lot of jagged edges). And the result? Pretty decent. The shutter speed however needed to be pretty low (1/40 at 100ISO and managed to kick that up to 1/80 at 200ISO).
Enlarged the aperture a bit more to make it around 1.25" and managed to get a decent photo of sunspots. (The photo is post-processed for brightness, contrast and colour saturation)
It is not safe to use x-ray film for viewing of the sun directly. To see an explanation as to why, see http://eclipse.gsfc.nasa.gov/SEhelp/safety.html. What I did not realise was that the most of the damage comes from invisible wavelengths. I use the live-view mode of the camera for observations. You could probably hook it up to a laptop for an enlarged image as well.
Anyway after a few mad dashes to local medical centers, I explained the requirement I had to a radiologist and managed to get a fully exposed x-ray for under 5$, it passes the safety test and I would be able to test it out with the sun tomorrow. Hopefully this would let me use the full aperture of the lens and therefore a much faster shutter speed with a low ISO.
It goes without saying that you need a solar filter. Over here in in SL, they are a bit too hard to come by. Previously when I was photographing and viewing the annular solar eclipse in 2010, I used a cut up x-ray film with my Canon S2IS (this method is debated). The problem this time is that I now have a Canon 550D, whose lenses have a much larger aperture and the original x-ray cut ups wouldn't work anymore.
1st attempt: Use a type of coloured cellophane that is available over here as a filter. A single sheet is way too thin so tried stacking up about 10-12 on each other. However it diffuses the light so much that it is barely of any use.
2nd attempt: Center the x-ray piece on the lens and try with that. Well that works when it is fully zoomed out, but as you start zooming in, the sun tends to get in from the sides. So no joy there.
3rd attempt: My dad comes up with this ingenious idea; Cut up a cardboard ring that will cover the area outside the x-ray film. About five minutes later we ended up having a cardboard ring with an aperture of about an inch (with a lot of jagged edges). And the result? Pretty decent. The shutter speed however needed to be pretty low (1/40 at 100ISO and managed to kick that up to 1/80 at 200ISO).
Enlarged the aperture a bit more to make it around 1.25" and managed to get a decent photo of sunspots. (The photo is post-processed for brightness, contrast and colour saturation)
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| The Sun - There are five clearly visible sunspots in the upper half of this photo. |
It is not safe to use x-ray film for viewing of the sun directly. To see an explanation as to why, see http://eclipse.gsfc.nasa.gov/SEhelp/safety.html. What I did not realise was that the most of the damage comes from invisible wavelengths. I use the live-view mode of the camera for observations. You could probably hook it up to a laptop for an enlarged image as well.
Anyway after a few mad dashes to local medical centers, I explained the requirement I had to a radiologist and managed to get a fully exposed x-ray for under 5$, it passes the safety test and I would be able to test it out with the sun tomorrow. Hopefully this would let me use the full aperture of the lens and therefore a much faster shutter speed with a low ISO.
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