“Legit” may be a strong word…but…let’s get real.
Learn how to easily create diffraction spikes on stars in your deep-space images without having to pull any magic tricks out of your post-processing hat. It’s dead easy.
To start with, I have to admit I am a bit of a purist when it comes to astrophotography.
That being said, there is a very wide grey area of artistic license in the astrophotography world. At the core of it is scientifically accurate data, assuming it’s acquired properly. However, there comes a point where too much data manipulation can make the final image less scientifically accurate, and I get a little blurry eyed when it comes to that. But, I digress. That’s a discussion for an entirely different day!
What are diffraction spikes?
Shown to the left in this exposure of the bright star Antares, diffraction spikes are artifacts that show themselves on brighter stars in our images when the beams of light entering the objective end (the business end) of your lens run into an obstacle and are interfered with and bent, causing the light to spread out.
So yes — we are capturing an image of the bending of light. There’s nothing like messing with photons in the middle of the night to get your juices flowing!
In this short tutorial I’ll show you how to create this phenomena in your images if you are using a refractor telescope or a normal lens. We have the power, we can bend the light! There is no spoon!
Now, if you’re imaging with a telescope that uses a secondary mirror held in place by a spider (a metal cross piece), you already get them, like this. If you’re not, and would like to play around with it…read on.
Why would you want to do this?
You might want to create diffraction spikes on your stars because you think it’s pretty, and that’s okay.
I did it for two reasons — I thought it was pretty, but, I also knew I was going to be imaging a target that was…a little boring. It was an area around a bright star in Cygnus, Sadr, with not a lot of nebulosity but quite a few bright stars that I thought needed a little window dressing.
How to create diffraction spikes
It’s really, really easy. And, if you’ve got a deductive train of thought, you likely already know how after reading the above section about what diffraction spikes are. Regardless, keep reading to find out if you’re right!
What you need
- A thin piece of wire, approx 1 or 2mm thick. I’d recommend the A or D string from a guitar. It should be about 2.5 times the diameter of your telescope/lens objective in length.
- Some thin cardboard, like a cereal box
- Duct tape (of course)
- Wire cutting pliers
- Scissors or a sharp box knife
How you do it
- Cut a cardboard into a strip 3cm wide and ~3cm longer than the outer circumference of your telescope’s objective end.
- Wrap the cardboard strip around the objective end of your telescope, and use tape to secure a collar around it. (Don’t tape the scope!)
- Cut the wire in half to create two pieces that are about 6cm longer than the diameter of your telescope objective.
- Tape one end of a piece of wire to the collar you just made, and stretch it across the telescope objective, just tight enough so it doesn’t bend or warp. You just want it nice and straight, and secure it to the other side of the collar with more tape.
- Stretch the other piece of wire across the objective, making sure it is perpendicular to the first piece of wire. Secure with tape to the collar.
- Done! Shoot some stars!
- Seriously, that’s it.
It really works!
During my testing, I took some test exposures to see how well it worked before I committed. Needless to say, I was happy with the results. Most of these images (except for Sadr) are very unprocessed, and all were taken with the exact method and setup shown here.
I love your site but that popup that comes up every time is pretty annoying.
Hi Stephen — thanks!
The popup should only come up every few days, maybe you have cookies disabled in your browser? Let me know!
Very cool! I want to switch to a refractor soon but my wife loves the spikes of the newt. This trick is a life saver.
Great! That was part of the reason I did this as well, and it works great! 🙂
I suppose that you can get more complex diffraction patterns with more wires. Gotta give it a try!
Indeed you can, Chris. Have fun, get creative!
Nice tips! Anyway will that work on camera lens for wide field astrophotography too? Or can only work by using refractor telescope?
Yes it will work on a normal camera lens, you might have to play around with the thickness of the wires though. But it will work! A telescope is just a big lens. 🙂
Just made one. Much rather do that than mess about with photos. Thank you
I have a lengthy background as an animator in feature films and commercials. Every single thing we do is a cheat to make things look better. When you’re a noob you feel guilty that you are doing whatever it takes to get a director to sign off on something. I just did a google searching wondering why Pixinsight doesn’t have a “make diffraction spikes” tool. It’s funny to see people get worked up over artistic choices when that’s all we have to differentiate our Astro images from one-another. I’m new to Astrophotography but not new to enhancing photos and videos on a grand scale to grab more audience attention. When in doubt add a lens flare or more atmospheric fog. It doesn’t even have to make sense in a scene as long as it looks good. Adding data to space photos does seem wrong but I’ve used Trapcode shine and Starglow for 25 years so it will be difficult for me to resist using plugins to enhance photos 😆