Fork me on GitHub

Micha Gorelick

programmer, builder & astronaut

failed telescope night
fun under the clouds
So, after a while spent getting my telescope aligned (and, of course, staring at M41 and M42 for a while), the clouds came in before I could get the camera ready. When I was done cursing the clouds and the cold I had been sitting in, I decided to take pictures of Toronto to gauge the camera.

I was using my 8" Celestron (f#=10, focal length=2032 mm). It's a great telescope although it takes a magical touch to get aligned.

This is the main picture of interest: the symbol of BMO on top of First Canadian Place (which is 2580m away from my balcony). From my calculations, the symbol is 6m tall which means I'm capturing about .1332° or 2.32e-3rad of the sky! (I got this number by doing [; 2\cdot tan^{-1}(\frac{6/2}{2580}) ;])

By the way, the picture of the moon I took before was with my astroscan (f#=4.1, focal length=445cm). It's a great telescope to bring around and it's really quick to get set up and start observing, although the optics aren't that great which leads to a lot of artifacts. Also, I like the tactility that comes with manually aiming the beast.

While I was first testing the camera I took the following picture from 37m away:
Since my camera is 9.5cm tall and it takes up 46.1% of the height and 34.6% of the width of the image we can get... (5.563e-3, 7.413e-3)radians = (.318,.424)degrees=(height,width) degrees!

So, if we take the differences in f# into account, both measurements agree! *phew*, well at least now I can say tonight wasn't a waste.
blog comments powered by Disqus