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6 Tips to Create Compelling Star Effects, Sun Stars, Starbursts, or Sun Flares in Your Photographs

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Over the years, I have noticed how different lens and aperture combinations create distinct effects on the image surrounding distant light sources in photographs. Another place that this effect is commonly seen is in famous astronomical images from terrestrial and space-based optical telescopes. In fact, we are so used to seeing “pointed” stars in photos that many of us, when we hand-draw a star on paper, rarely draw a point of light or a disk; we draw a multi-pointed star. What causes these effects? How can they be altered? Can they be removed? Can they be enhanced? And, of equal importance: what should we call them?

You will find lots of variations of names for this effect. Some examples are sun stars, starbursts (not to be confused with the candy), sun flares (not to be confused with solar flares), and more. For the purposes of this article, I will use the term “star effects.”

Six-pointed stars at a pulp mill, in Manila, CA ©Todd Vorenkamp 

Like many things in the photographic world, knowing the whys-and-hows can help you maximize the effectiveness of a practice or technique. Star effects are no exception, so, in this article we will talk about the physics behind the effect.

Before we dive in, know that for every photographer who loves the star effect, there are photographers who do not like the effect and who are trying to avoid it. It is all a matter of aesthetics and personal preference.

Diffraction

Diffraction is a phenomenon that involves the modification of waves (direction and speed) caused when those waves pass through a narrow opening or past the edge of an object. When waves pass by an object, their direction is altered. When passing through a small opening, the same thing happens, with the end result being the spreading of the wave pattern. The term is applied to light, sound waves, and other types of waves (water, for example), as wave physics are similar through different media.

If the light passes through a perfectly circular opening, a small diffractive disc is created—the Fraunhofer diffraction pattern (named in honor of German optician Joseph von Fraunhofer). Instead of a point of light, you will see a small disc surrounded by a number of faint rings known as the Airy Disc (named after Sir George Airy, England’s Astronomer Royal from 1835-1881).

In photography, diffraction occurs when light waves pass through the diaphragm of a lens. It is most pronounced when the opening of the aperture diaphragm is constricted. Many photographers mistakenly believe that they get maximum sharpness at minimum aperture openings. In reality, the image gets softer because of the diffraction of the light. Because of this, diffraction gets a bad rap in the photo world, but it is diffraction that causes the star effect.

Ideal Airy disc for

resolving a single point of light

Diffracted light causes discs to

overlap, resulting in softer unresolved imagery

Tip 1: Safety first

If photographing with the sun in the frame, be sure to protect both your eyes and camera. Pointing a camera directly at the sun can be very dangerous for your eyes. In general, to get the star effect, the sun will be off-axis, but, when composing, take care to not swing the lens directly at the sun. If the scene is still too bright for a DSLR viewfinder, try the live view mode, if available.

14-pointed star around a nearby star ©Todd Vorenkamp 

Not only can the light be bad for your eyes, it can be bad for your camera. Identical to the principle used to burn leaves with a magnifying glass, focused bright sunlight from a camera lens, especially a telephoto lens, can damage the internal components of a DSLR or damage the sensor of a mirrorless or point-and-shoot camera. Be careful!

Lens and Aperture  It is the phenomenon of diffraction that creates the star effect on distant single-point light sources and, sometimes, on specular highlights on an object in the frame. The size, shape, and characteristics of the star effect are a function of the size of the aperture opening (diffraction of light passing through an opening) and the number of aperture blades on the aperture diaphragm (diffraction of light passing an object).

The design of the aperture diaphragm has a profound effect on the star effect. Sometimes, your gear isn’t critical to a successful image, but when you are dealing with star effects, you will find that lenses have vastly different characteristics when it comes to this type of diffraction.


f/2.8


f/4
 


f/5.6


 f/8
 

f/11

f/16

f/22

©Todd Vorenkamp 

If the aperture blades form a perfect circle, you will not get the star effect and you will, instead, have distant highlights producing Airy Discs on your image. In general, the circles emanating from the disc will be so small and faint, depending on the light source’s distance and intensity, that you will not see the rings. Several modern lenses feature “rounded aperture blades” to help form a circle for the light to pass through.

Tip 2: Use smaller apertures

When it comes to star effects, in general, the smaller the aperture, the more pronounced the effect will be (there are other considerations that I will discuss later). However, just as you are increasing the diffractive effect from distant light sources, you will also be increasing diffraction throughout the image. There is a trade-off.

When the aperture diaphragm forms a polygon instead of a circle, we get the star effect. The light streaks or star points of the effect extend from the sides of the polygon formed by the blades.

This is where it gets cool. With diaphragms that form a polygon, if you have an even number of aperture blades, you will get one point per blade extending from the side of each blade intersecting with the point from the opposite side. Because the opposite star points overlap, an even number of blades creates one visible star point per blade. A 6-blade aperture produces a star effect with 6 spikes.

If you have an aperture with an odd number of blades, the diffraction extends from the blade across the opening where it does not intersect with its opposite point. Therefore, because the start point does not overlap an opposite point, an odd number of diaphragm blades creates two star points per blade. A 7-blade aperture produces a star effect with 14 spikes.

Tip 3: Know your lenses

Experimentation with your lenses will help you determine the ideal star effect f/stop. If you are on a star-effect mission, spend time with all your lenses and figure out which ones produce the best star effect. Then, if you are planning an image where you want your strongest star effects, break out that lens. Or, if you want to avoid it (star effects are not for everyone), use the lenses that tend to not make the effect.

One other thing with the lens that affects the start effect is the ability of the lens to handle flare. The better the optical formula and multi-coatings are able to reduce lens flare, the sharper your star effects will be. If the lens is incompetent when it comes to dealing with flare, you will see softer, less defined star effects.

Tip 4: Beware of filter flare

Sometimes flare can be caused by your UV filter. If you aren’t getting the star effects you desire, or if you are getting other flare, try removing the filter to see if it has a positive effect on your images.


Telescopes are designed to maximize the amount of light captured by the optical tube. Because of this, they don’t usually have aperture diaphragms. So then, why do we get the star effect in images from optical telescopes?

The star effect is created when the light passes by the secondary mirror that lives inside the tube of a reflecting Newtonian or Cassegrain telescope. That mirror is suspended inside the optical tube by struts and the number of struts creates an associated number of star points. 3 struts produce a 6-point star. 4 points render a 4-point star.

A detailed investigation of images from the famous orbiting Hubble Space Telescope shows that the scope is equipped with 4 struts to support its interior mirror.

 

Considerations

Day versus night  Star effects exist in both daytime and nighttime photography. The star closest to Earth, the Sun, can give you great star effects during the day, as can the sun’s reflection from shiny objects and windows. At night, bright, distant light sources can produce the star effect. One bright, distant source of reflected light is the moon. With a wide-angle lens, you can get some great star effects from Earth’s natural satellite, too.

Exposure  Your exposure affects the intensity of the star effect. The longer the exposure, the more star effect you will see, until the point at which the entire image is overexposed. The brighter the highlights in a photo, the more star effect.

In night photography, burning out highlights, such as street lamps and other artificial light sources, is sometimes unavoidable. The amount you let those highlights burn is directly related to the size and intensity of the star effect. How much you see of the star effects is dependent on the contrast in the scene.


f/2.8


f/4
 


f/5.6
 


f/8
 


f/11
 


f/16
 

©Todd Vorenkamp 

Tip 5: Watch for other flare

Bright light sources that are entering the lens from the main axis can produce undesirable lens flare. Often, you can see this through the viewfinder when you compose the image. Not all lens flare is bad, and not all of it needs to be avoided, but you should be conscious of it so that you can take steps to remove or manage it in the frame.

Contrast  Contrast plays a big role in how your star effects stand out. If a distant lamppost, surrounded by an ink-black sky, is creating your image highlights, you might get some great definition and an eye-popping star. If that light source has a relatively bright area behind it, you will lose some of your star effect.

The sun, if hanging in a low-contrast, bright sky, will produce less of a star effect than if in a deeper blue sky.

Tip 6: Mask the light

During the day, you will find that partially blocking the light from the sun will help give you a more dramatic star effect. This is because, by blocking part of the light source using trees, buildings, or other objects, you will increase the contrast in that region of the frame and make the star effect more pronounced.

Masking the sun to create a star effect ©Todd Vorenkamp 

Do this with your own eyes (don’t stare directly at the sun). Shade a portion of the sun with a building or tree and, through your peripheral vision, note that your eye produces star effects too! This is caused by the fact that nature did not give our eyes a perfectly circular iris.

Subject-to-lens distance  The closer you are to the light that is producing the star effect, the larger the star effect will be in your frame. In fact, you can use the relative sizes of the star effects to illustrate depth. For example, the Brooklyn Bridge images in this article show star effects on the more distant Manhattan Bridge and Manhattan skyline that help reinforce the depth of the image.

Focal length  Focal length is not directly related to the size of the star effects that you can create. If you change from a wide-angle lens to a telephoto lens, you might amplify the size of the star effects, but this is more of a function of getting “closer” to the subject versus an effect created by the lens itself. Of course, some lenses lend themselves to producing better star effects and some lenses, regardless of focal length will not produce crisp stars.

On a zoom lens, you can change the size of your star effects by zooming in or out, but the relative size and shape should not change drastically, as you are sending light through the same aperture.

A busy Brooklyn street ©Todd Vorenkamp 

You can make the star effects larger by zooming in or moving closer, but you cannot enlarge them in a given image without changing aperture.

Quality of Light  As with all aspects of photography, the quality of light has an impact on your image. Star effects are no exception. Haze, smoke, fog, etc., can serve to reduce the sharpness of the effect. The relative size and brightness of the light source has an effect as well. Smaller and brighter works best. Obscuration of the light will either make (see Contrast, above) or break your star effect, so be prepared to reposition your camera to capture the best angle for the effect.

Filters and Post Processing  If your lens is not producing the star-points effect you want it to, you can artificially create this effect by adding a “Star Effect” filter to your lens (hence my decision to call the phenomenon by this name) or create the effect in post processing with some image-editing software.

Star Effect Filters are etched in a crisscross pattern and are designed to intentionally diffract light and create the star point effect. They also create some rainbow dispersion effects and generally soften the overall image. Star effect filters come in all common lens thread sizes and have varying designs that produce star effects of different numbers of points (2 to 16), different point patterns (for example: North Star, streak, vector), different color streaks. B&H Photo currently has more than 800 variations. Check them out and use them to give your photos a creative twist.

You can also add the star effect in Photoshop and other editing software. As with most things in digital editing, there is a plethora of ways to do this, so scan the Internet for the star effect/starburst/sun star tutorial that works best for your image.

Starry, starry nights (and days)  Love them or hate them? Cool trick or cheesy distraction? Share your thoughts and tips and tricks for either making more dramatic star effects, or avoiding them all together! Thanks for reading!

Thank you for joining our journey into night photography! For more Visualizing the Night content, please click here: Visualizing The Night and share your enthusiasm for the art below in the comments section or reach out to us on social media using #visualizethenight. Thanks for reading!

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Is it safe for our camera to take photos of a masked sun or should we be using a certain filter?

Hi Diana,

Good question. Here is one set of semi-answers: https://www.bhphotovideo.com/explora/photography/features/debunking-myths-surrounding-sun-and-your-camera

If the sun is low on the horizon, you should be fine. When it is overhead, it is more intense, but I have found that very fast or accidental exposures (like the one in the article above) do not have an adverse effect on the camera.

Thanks for stopping by!

hi, 

can i know how to get a 4 point star in daylight? will simply controlling the aperture help (assuming the lens can produce these flares)?

Hi roshnara,

Four-pointed stars are tough. I dont know many lenses with 4-sided apertures, but I am sure there are some. You might need to get a 4-point star effect filter to get your effect.

Good luck!

Thank you for this article, truly helpful, your demonstrative aperature examples are excellent. 

Hey Rachel!

I am glad you enjoyed the article! Thanks for stopping by!

I loved this article. Clear with simple enough rules on how to get star bursts, but technical enough so I truly understoodwhy the 'why' and can (hopefull) control the effect now..I have been wanting to produce star bursts for a long time with only accidental success.  Now I have 'seen the light' and know I was making the mistake of using too wide an aperature (I love shooting 'wide open')  No wonder I couldn't get them. I particularly liked having identical photos at different aperatures to show the difference. Great job! Thank you Tood and B&H.

Thanks, NancyB!

I am very glad you enjoyed the article! You can still shoot wide open...you just need a star filter to get the effect!

Check out this article for examples:

https://www.bhphotovideo.com/explora/photography/tips-and-solutions/10-tips-and-tricks-photographing-holiday-lights-and-candles

Cheers!

I recently bought a Fuji X-E2s which came with a Fujinon Aspherical lens 16-50 mm and 3.5 to 5.6. I do mostly landscapes, often by the sea before and during sunset. I noticed on first use a fourteen-point star effect round the sun and later asked about it at the shop. The guy said I had taken the shot at f22 and I needed to use less than f11. I don't much like starburt effects so I next time there's some, using a much lower f stop will reduce or eliminate it. The article seems to confirm what I was told.

Hi Alan,

Yes, with wider apertures (smaller aperture numbers) you will get a less pronounced star effect! Some love them, some don't!

Good luck!

Thanks for reading!

The diffraction spike is caused by the edge of each diaphragm blade, not the vertex of intersecting blades. The Wiki article illustrates it rather well in the section headed "Diffraction spikes due to non-circular aperture."

Hi Steve,

Thanks for the correction! I will amend the text above to indicate that the vertex is not the culprit!

I must have been sleeping through that part of optics class and did not see this Wiki page!

Great article! Thank you.

Thanks, Patrick!

Thanks for reading! Sorry for the delay...we were on break!

Abcolutely great the article.

Thanks a lot

Thanks for the kind words, Lada!

I am glad you enjoyed the article!

Great tutorial!

Thanks, Enrico! Happy New Year!

Todd - Thanks for the excellent discussion on star effects.  I am an astro-photographer and often see diffraction effects on bright stars in my images, due to obstructions across the aperture of my telescope.  Sometimes in post-processing I would like to add the same diffration effects to dimmer stars in the same image, using Photoshop.  Can you tell me how to do this in Photoshop?  I cannot find how using Photoshop help menus and keywords like diffraction, flare, star effects, etc.

Hey M.J,

Thanks for the kind words! I am glad you enjoyed the article!

I just did a web search for "Photoshop Starburst" and there are many ways to build that mousetrap. Some are easier than others...and some look better than others. Instead of regurgitating one here, I will let you check them out and see which one works best for your workflow.

Good luck and let me know if you have more questions!

BrianHi. Just found this really helpful article and particularly like the 'physics' info included. Always liked to know the 'whys and hows'.Good clear explanation and illustrations. Thank you.

Hey Brian! I am very glad you enjoyed the piece! Thank you for reading!

Very informative article. Many thanks for this

Hi Donald,

You are very welcome! Thanks for reading!

Great article that lets me know the way to create the star effect when photographing. However, when checked one of my photograph, there is star effect though the photo was taken with a lens (Tamron SP 24-70mm F/2.8 VC DG USD) with round aperture of 9 blades. Why? Is the round aperture not a perfect circle and acturally still a polygon?

Hi Lijen,

Your theory is correct. It is extremely difficult to make a perfect circle, even with curved aperture blades, when you are overlapping blades to create that circle. The curved blades help a lot, but there is still going to be a slight "corner" created where the blades overlap - especially at smaller apertures.

Embrace the stars! Thanks for reading, Lijen!

I have long from (late 60s) created star effects by shooting through a piece of window screen, A bonus is you can vary effects by rotating, bending, or stretching the screen.  Star effects on the cheap, when and how you want them.

Great tip, Ronald! Thanks for sharing and thanks for reading!

I've noticed star effects on a few of my photos.  They were happy accidents to me but after reading your article, it's good to know how it happened and that I have some control in creating them.  I like the "natural" phenomenon much better than samples I've seen using star filters.  I didn't even know it could be done using Photoshop.  Thanks for a very informative article. 

Hey Virginia!

Thanks for reading and keep shooting for the stars!

Great article. I particularly enjoyed the way all the different forms of star effects were broken down and explained -- especially the part about telescopes and masking. Also valued the reminder that the smallest aperture on a lens is not the ideal aperture in terms of sharpness for that lens. Found this out the hard way shooting objects with type. At f/11 the type was sharp, but at f/22 is wasn't. Cool Brooklyn & Manhattan Bridge, and docked ship photos. My favorite lens has 5 apertures, and now I know why it creates stars with 10 points -- thanks. I recently shot a skateboarder at a concrete skate park in California. With the sun behind him, my lens at f/22, and with part of his body masking the sun, the star effects and lens flare made the shot work. 

Hey Cubby! I am glad you enjoyed the article. Thanks so much for commenting and reading the B&H blog!

Wow!  Todd Vorenkamp  you daytime and nighttime  star effect is so beautiful. I impressed from your effect and I got a unique knowledge. 

I made a starry effect on the dark sky in Photoshop. I used Adjustment of Levels for Noise technique to make star effect. 

Hey Ali! Thanks for the compliments! All the effects in this article were created by the lens, but I like your technique too! Thanks for reading and sharing!

Thank you for the information, very informative.

Thanks and thanks for reading, Fred!

Excelent Articla, with clear text and precise details. Thanks so much !

Thank you, Jose! I am glad you enjoyed the article!

Thank you for the tips.  The article was extensive and informative. I will try to get the star effects with my camera. Thanks.

Good luck with the stars, John! Thanks for reading!

Great article. I had no idea that star effects were affected so much by the number of blades in the  aperture diaphragm.

Thank you :)

Hey Bob,

Thanks for reading and thanks for the compliment!

Thank you Mr. Vorenkamp and thank you B&H for making this so much more than a great place to shop.

Thank you for reading and thank you for the compliments, Adrian! It means a lot!

This is really pld and simple stuff. I had hoped you had something interesting on this post. 

Thanks for reading, Roy. I am sorry you didn't find anything interesting in this article.

Another day, another great lesson learned! Thanks so much.

Thanks for reading, Ram! I am glad you enjoyed the article!

You've provided an excellence resource with this article.  Your illustrations are spot on, and the progressive aperture series really dramatize the effects of different settings.  You've covered it all.  Excellent.

Thank you, LARRY! I am glad you enjoyed the article and thank you for reading!

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