January 2024

Welcome to Hank’s January 2024 Astrophotography Blog! In December I was taking photos with the HyperStar lens, that gives a wide field of view and has a focal ratio of f1.9. What that means is that the photos cover about 3 ½ degrees of the sky (a big view) and the camera can capture a great deal of light in a hurry (it’s fast!).

This month I switched over to a setup that lets me move in much closer, where the photos only cover about a half of a degree of the sky, and the focal ratio is f10. What that means is that I’ve zoomed in to see smaller objects in the sky and it takes longer to get the light needed to take the photo. The focal ratio is found by dividing the length of the telescope by its aperture, or the size of the opening that lets in the light. Both setups have the same aperture, an 8” diameter hole, so by lengthening the telescope and the path that the light travels in the telescope, it allows me to zoom in, but it takes longer to capture the amount of light I need. With the HyperStar lens my focal length is about 390 mm. With this month’s set up, my focal length is about 1860 mm.

With the change in setup this month and using the new post processing software and the Off Axis Guider I talked about last month, I was busy experimenting with my exposure and gain settings on the camera. I find I’m taking more photos of the same objects over and over, using different settings, to try and better understand why I get the results that I do.

To start off, I took a number of photos of galaxies.

The next pair of images shows a reflection nebula Orion (NGC 2064), and I realized that it was close to another nebula, so I moved the telescope a bit and captured them both.

Here are a few other nebulas I’ve been trying to use to help me experiment with the camera settings and new post processing software, SIRIL.

One night this month I was capturing 2 minute exposures (subs) for an hour on M78. The next day when I got around to processing it, there were a bunch of faint streaks across the image. I opened up each one of the files to see what was going on and 18 of the 38 images had different streaks across them. I did a little research, and it turns out that the streaks are trails from geostationary satellites hovering over a spot on Earth, like weather satellites and such. The stationary satellites look like streaks because my telescope is moving to track the stars, so I guess it shows that it was me that was doing the moving and not the satellites. Orion is a popular latitude for those satellites! It seems that no matter where humans go, we leave a lot of stuff behind.

Until next month, Clear Skies!

Hank