Field of View of our Canon 450D and Two Lenses
In a previous post, I reviewed the fields of view for the Canon 60Da with the C925 telescope. In this post, we look at the fields of view for the Canon 450D camera and the [...]
In a previous post, I reviewed the fields of view for the Canon 60Da with the C925 telescope. In this post, we look at the fields of view for the Canon 450D camera and the [...]
In a previous post I reviewed how the angular field of view of an image sensor is related to the focal length of the optical tube and the sensor size. We then applied this analysis [...]
In an earlier column about field of view, I showed that the focal length of a telescope really translates image size at the focal plane into an annular size of the object. The angular size, [...]
As noted, I was able to use a 30 mWatt laser pointer to take out a streetlight. But, I needed to modify the laser in three important ways to turn it into a practical solution: [...]
There is a very obnoxious street light located behind the dome of the Addie Rose Observatory. It is almost in the sight line to Polaris. This make most of the views around the celestial north [...]
A limitation with panoramic stitching on the iPhone can be overcome to create stunning, high resolution panoramic images using any camera and Hugin, a free tool. The iPhone has a built-in panoramic mode for its [...]
published in EE Times Looking for that perfect Christmas gift that will give your 6- to 14-year-old a taste of the most basic engineering principle — that you can change your world if you can [...]
When we look at a few Hubble photos of distant galaxies we may get the impression the universe is a static place. Other than the occasional supernova brightening, the galaxies we see haven’t changed much [...]
Jim Williams in his lab at Linear Tech, with his beloved Tek scopes and assorted breadboards. I was saddened to learn last year of the passing of Jim Williams. He died on June 10, 2011 [...]
I’ve had this Keithley 196 6 1/2 digit multimeter for about 25 years and it works as great today as it did when I first got it. I usually use it on the voltage scale [...]
The Teledyne LeCroy WaveAce 2034 is a “gateway drug” into digital scopes. It has the front panel interface typical of traditional analog scopes, but with lots more buttons and features which enable us to tap [...]
I’ve had a recurring problem with my Celestron SCT C6 telescope since I received it in Feb, 2008. Every now and then, especially when I am slewing the scope, and more often in cold weather, [...]
This is part 1. The properties of telescopes are often presented in a confusing way. In fact, it is simple if you keep in mind what a telescope is really doing. […]
This is part 2. To read part 1, click here. The focal length of a mirror system is a direct measure of the translation of the angular size of an object to its spatial size [...]
If you missed out on summer camp as a kid, as I did, it’s not too late. But this time, you don’t have to rough it. For the last few years, I’ve attended various star [...]
“Twas the night before Christmas and all through the house… ” is the way the classic poem by Major Henry Livingston Jr. 1748 – 1828, begins. Over the years, 849 variations have been created each [...]
The earth rotates, sweeping the star field across the sky. If we take a long exposure of the stars, with the camera stationary, the stars will appear as star trails in the image. We can [...]
When you are all alone in the middle of the wilderness, how do you hook-up a camper to your car’s hitching ball? If the camper is not secured, you will be stranded in the middle [...]
We have three cats. Two of them, 9 year old males, are at least 15 pounds and the third, a 2 year old female, that weights only 8 pounds, eats (and poops) like she is [...]
Workout cycle from PlugOut, a supplier of exercise equipment that turns your sweat into electricity. The last time I was at the gym walking on the treadmill, I looked around and saw dozens of people [...]