Blog

Sol'Ex - DIY solar imaging

10.7.2022

For the past months I have been obsessing over solar astronomy, and specifically a device called Sol'Ex or Solar Explorer. It is a spectroheliograph, which allows capturing the spectrum of a very thin slice of the sun's disk. By capturing many images while scanning over the sun's disk with the device, you can reconstruct an image of the whole sun at any visible wavelength you want. There is a catch, though. To be able to resolve the very thin absorption lines in the solar spectrum, very strong…

Astrophotography rack case

25.9.2021

For a while now I have been controlling my astrophotography gear with a passively cooled Intel NUC computer, and powered them with a 110W 12V supply meant for a portable fridge. At first I kept both on the floor of our observatory, which isn't a great long-term solution. Looking for a cheap enclosure, I bought a metal mailbox and attached it to the telescope mounting pier. At first I thought it will be great, I can run all my cables through the mail slot in the mailbox. The mailbox turned out to…

Will It Blend?

30.5.2021

In my youth I was very enthusiastic about computer graphics, visual effects and such things. I was even considering trying to make a career out of it, until I went to study computer science. Around 2005-2006 I spent a lot of time learning how to use this open-source 3D modeling and rendering application called Blender, and some other related tools. Back then free learning resources weren't as readily available, and proper video cameras were super expensive and hard to get for a teenager…

HaloRay 3.0.0

20.2.2021

HaloRay has taken a leap forward again, and version 3.0.0 was released today with plenty of new features, the most important ones being: Realistic sky and sun rendering More ways to adjust ice crystal shapes Saving/loading simulations Crystal shape preview window In addition to these there are tons of small improvements and tweaks. You can go download the newest version on GitHub and take a look at the change log while you are at it. Let's take a closer look at some of the new features…

HaloRay - GPU-accelerated ice crystal halo simulator

24.1.2021

I have always been extremely fascinated by atmospheric optics like ice crystal halos. Halos form when sunlight, moonlight or artificial light refracts inside small ice crystals in the atmosphere. When these ice crystal populations cover a large enough area in the sky, you can see various light formations like spots, arcs and circles. They are relatively simple to simulate by tracing rays through simple hexagonal ice crystal shapes. Many simulators have been built in the past, but they are all…