Astrophotography by Jeff Dunehew

Interested in astrophotography? Maybe just astronomy? If you have questions, log in and post them below. I started out in astronomy with the intent of going into astrophotography. My first telescope was an Orion Skyquest XT10 (overkill) to intro myself into it. I had a lot of lessons learned by starting with such a big, non motorized telescope. It was a tough learning curve and I’m still not even past it. I started out just holding my iphone up to the lens to get several shots of planets and the moon, but that did not last me very long. I was ready to get better shots. It’s been a struggle to learn all of the processes and techniques needed to get images. For example, if you wanted to take a picture of a planet, you record video – that usually surprises most people. Taking video of a planet can actually be fairly difficult. If you were like me using a manual telescope, then you only have the time that the planet is in the frame. Depending on the lens you are using that may not be very long at all so you sometimes have to move and manually track the planet yourself. Once you get that video and look at it on a computer the planet is bouncing all around the monitor from you moving the scope and the Earth’s rotation. Now you have to use software (PIPP) to crop that video where it’s just a video of the planet in the center. Once you have that you can import it into a software called Registax where it strips the video frame by frame and stacks the images on top of each other to give you as much of a detailed image as you can get. There is a lot more to that process such as which frames do you pick, where to set focus points, editing image attributes (contrast, brightness), etc..

Want to take an image of a non planetary object such as a Messier object? Completely different process. Where you were using a modified webcam to take a “picture” of a planet, now you want to use a modified SLR camera or a specific astrophotography cam. To take a picture of let’s say Orion Nebula (pictured below), you would want to take many many photos with long exposure times. Once you take these you need to take dark and light photos. For example, the dark photos you put the cover back on the telescope and take several shots. What this does is let you remove the imperfections of the camera lens, mirrors, etc from the picture. In the end once you have all of these photos you stack them together just like you did with the Registax program.

Taking photos now with the camera I use (equipment listed below), I have an F stop of around 10. To attach my camera to my telescope I remove the lens that you would normally look through and with an adapter on my camera I can lock it in where the lens was attached. There is a company that makes a product called a Hyperstar that allows you to place the camera on the front of the telescope. Doing this drops the F stop down to 2 from 10. It allows me to take very quick photos and get excellent pictures without having to take super long exposures and worry about stacking. However, if you still go through all of that process you get fantastic images (I have not done this yet).

Equipment I use now:

Telescope – Celestron Edge HD 9.25

Mount – CGEM II

Star Tracker – Starsense


Camera – Nikon D5200 with T adapter