Today, I announced my bid for Fort Collins City Council, in District 5 (the current councilmember, Kelly Ohlson, is term-limited). You can read all about it at http://www.rosscunniff.com - it should be a great adventure!
I got two GoPro Hero3 Black cameras and am planning a panoramic project with them. However, to do the project correctly and accurately, I need a good read on their field-of-view. So, I set up a tripod and a grid and a tape measure, and took a few photos. Here they are, desaturated and contrast-enhanced, with central red dots and some annotations. First, measuring the diagonal FOV:
Next, the horizontal FOV:
Finally, the vertical FOV:
The front of the camera lens was almost exactly 17 inches from the grid. The camera body started about 17.25 inches from the grid. Assuming the sensor is embedded some distance into the body, I used an estimated field-to-sensor distance of 17.5 inches. This yields the following field-of-view, in degrees:
Doing a little interval math on the field-to-sensor distance shows these angles are accurate to about plus or minus 1.5 degrees.
Interestingly, Photoshop seems unable to correct the barrel distortion of th…
Today (well, technically, yesterday now) was the 2016 Transit of Mercury. These happen much more frequently than transits of Venus. Mercury transits happen about every 7 years (13 or 14 times per century). I was watching the weather anxiously - I wanted this to be a dry run for the 2017 eclipse, but I was not able to travel on Monday so I was hoping that the weather would suffice here in Fort Collins. I watched the Fort Collins cleardarksky page continuously over the weekend, which helped me stay calm and collect my equipment to prepare for the expedition.
Monday morning started with low clouds which cleared by about 6:30 or so - just in time for me to have all my equipment set up:
From left-to-right, these are:
A Meade 2045 4-inch Schmidt-Cassegrain telescope on a tripod, with a glass front-surface solar filter. This was for visual use - which turned out handy, since I had about 8 or 10 visitors.A Lunt Solar LS60PT pressure-tuned H-alpha dedicated solar scope, with a Hinode Sol…
A few years ago, I converted various planet maps to icosahedral models. You can print these out, cut along the solid lines, fold along the dotted lines, and have a nice icosahedron to play with. Since then, two more robot spacecraft have created global maps of planetary bodies. Most recently, the New Horizons spacecraft flew past Pluto. Here is an icosahedral projection of the data we have so far:
Also fairly recently, the Dawn spacecraft has orbited both Vesta and Ceres, two of the largest asteroids (or "dwarf planets" as the new nomenclature has it) in the Solar System. Here are icosahedral projections of those two. First, Vesta:
Next, Ceres - note the mysterious white spots toward the upper right: