Any advice on how to remove moon "rays"? (Looking to learn how to take a photo without them, not remove them in post)

Artistic opinion - is it too underexposed?

The picture was shot at shutter speed 30", f/20, ISO 800, exp comp of -2/3, focal length of 19.2 mm. Lens is 15-45 mm and F3.5 - 5.6.

Given the data and capacity of the camera, can you suggest of exposure adjustments to solve the sunstar?


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    \$\begingroup\$ Thank you for responding. The latter, how to take a photo like this one, without rays. I just finished searching in Google that these are called "flares", and usually occurs when the source of light directly hits the lens. And this is more prone for zoom lens (what I'm currently using since I don't have prime lens yet). Any other cheap/practical alternatives you can suggest? \$\endgroup\$
    – Erly Marie
    Commented Dec 11, 2019 at 8:28
  • \$\begingroup\$ Could it be that you have an x-t100, not an x-100 (as tagged)? \$\endgroup\$ Commented Dec 11, 2019 at 16:34
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    \$\begingroup\$ Related: How do I capture the moon and its surrounding context? \$\endgroup\$ Commented Dec 11, 2019 at 16:48
  • \$\begingroup\$ Erly, inspired by your comments, I've posted this: photo.stackexchange.com/questions/113534/… \$\endgroup\$
    – OnBreak.
    Commented Dec 11, 2019 at 17:34
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    \$\begingroup\$ That is a very odd choice of camera settings. You might want to take some time and learn more about how ISO, shutter speed and aperture affect the photo. You've chosen very high values for all three, and that doesn't really make sense. Also, yes, the photo is super under-exposed. \$\endgroup\$
    – JPhi1618
    Commented Dec 12, 2019 at 15:44

3 Answers 3


The "ray" effect is known as sunstar. There are 2 conditions to achieve sunstars :

  1. use a narrow aperture (like f/16).
  2. point camera to small and bright light source.

You achieved that effect very well. However, it doesn't serve the photograph. In the photo, the subject seems to be the moon. However, it is hard to tell it is the moon by looking at it only. We only guess it by looking at the surrounding night cityscape.

To picture the moon as we know it (with dry lands and craters), you can follow this automated method :

  1. Use Aperture priority mode with spot metering mode.
  2. Choose the largest aperture available (f/5.6 or wider).
  3. Place the spot meter on the moon and take a picture. The spot meter zone is often at the very center of the frame (~2% of the area). Check your camera manual.
  4. Check if it is correctly exposed. Use Exposure compensation to achieve proper exposure.
  5. Now the moon is properly exposed but in the middle of the frame. If you want to change the composition of your image, dial the values of your properly exposed frame in manual mode. Compose and take your shot, and voilà !

There are other methods to properly expose/compose the moon like Exposure Lock, manual mode... Pick whatever you see fit as you gain experience.

You may observe that the moon is very bright compare to the landscape it surrounds. In fact, most moonscapes are composite shots : one long exposure for the landscape itself and one short for the moon. Then both exposures are fused within the image processor to use the best part of both images.

Other tip to photograph bigger moons (other than long focal length), the moon can appear bigger when it rises and sets. Also, depending on your geographic location and season, the landscape can also be more bright as it may not be quite night time. In these conditions, you may pull a single exposure moonscape.

Happy mooning !

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    \$\begingroup\$ You can also use manual exposure knowing that the moon is lit by the sun, the sunny 16 rule, or to get an exposure more like most people expect, the loony 11 rule. en.wikipedia.org/wiki/Looney_11_rule \$\endgroup\$
    – Mattman944
    Commented Dec 11, 2019 at 10:26
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    \$\begingroup\$ Many night sky shots require 3 composites, one for the moon, one for the ground, and another for the stars, since the longer one for the landscape still isn't necessarily long enough to pick those up. \$\endgroup\$ Commented Dec 11, 2019 at 16:42
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    \$\begingroup\$ @DarrelHoffman another technique I often seen mentioned with landscape/stars images published in astronomy magazines is a long exposure for the stars with a flash at some point in the middle of it to illuminate the foreground for a fraction of a second. You'd presumably need to experiment to determine the right amount of flash to get suitable foreground contrast levels. \$\endgroup\$ Commented Dec 11, 2019 at 16:54
  • \$\begingroup\$ Alternatively, if you want to capture both the moon and the surrounding scenery in one non-composite shot, your best bet is to shoot when the constrast between them is lowest: when the moon is very low near the horizon (maximizing the amount of atmosphere between you and it) and/or behind thin clouds, or better yet, during daytime or twilight when the sky is not fully dark yet. Or use a flash, as @DanNeely notes, although that only works for fairly close objects. And you still won't get both the moon and any but the brightest stars in one shot with any of these tricks. \$\endgroup\$ Commented Dec 11, 2019 at 16:57
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    \$\begingroup\$ The moon looks larger to our brains when it is near the horizon. It does not look larger to our cameras, as its angular size is not affected by the atmosphere. The effect our brain perceives is a psychological one, not an optical one. \$\endgroup\$
    – Michael C
    Commented Dec 12, 2019 at 20:40

Opening your aperture fully, so the actual aperture opening is circular, will get rid of the sunstars - but can give just too much of a halo (even more with a fast prime lens than with a small zoom!).

The optimal choice of lens for your intent would be one that maintains a very near circular aperture no matter what aperture setting you choose - such will be either very modern or very old (1950s or 1960s old. 13 or 16 or more aperture blades. Such lenses might also give you disappointing contrast, though you should be fine at f/8 or f/11...).

  • \$\begingroup\$ The picture was shot at shutter speed 30", f/20, ISO 800, exp comp of -2/3, focal length of 19.2 mm. Lens is 15-45 mm and F3.5 - 5.6. Given the data and capacity of the camera, can you suggest of exposure adjustments to solve the sunstar? \$\endgroup\$
    – Erly Marie
    Commented Dec 11, 2019 at 14:08
  • \$\begingroup\$ M or A mode. Minimum aperture (whatever is minimum at your preferred focal length). ISO 100. Shutter speed as needed for best exposure. \$\endgroup\$ Commented Dec 11, 2019 at 16:33

More on the star effect...The aperture is created inside of your lens by overlapping petals, like this:

enter image description here

The following is pulled from BH Photo Video's article on the subject (https://www.bhphotovideo.com/explora/photography/tips-and-solutions/create-compelling-star-effects-sun-stars-starbursts-photos)

The arms of the star are created from light diffracting when moving through the lens and aperture. This affect is made more prevalent as smaller apertures are used, as in these examples:

enter image description here enter image description here enter image description here

The number of arms that you get is dependent on the number of petals that the aperture uses:

enter image description here

So, if you are looking to not get any stars, you need only use a larger aperture.

But, if you are looking at creating some stars from your point light sources...then it pays to know your lens. Odd-number of aperture petals will have more points and those points can be made smaller and larger by controlling the aperture.

Consider it a new artistic tool in your toolbox.

  • \$\begingroup\$ Do we have to pay to know what lens you used for these examples ... handles urban nightscape reasonably well it seems. \$\endgroup\$ Commented Dec 11, 2019 at 22:15
  • \$\begingroup\$ @rackandboneman I'd tell you if they were my shots. I took (and cited) the examples from B&H's Knowledge Article on the topic. From what I've seen, they're really good about responding to comment inquiries...so give that a try? \$\endgroup\$
    – OnBreak.
    Commented Dec 12, 2019 at 16:45
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    \$\begingroup\$ @rackandboneman It should be fairly obvious by looking at the f/22 image that a lens with either five (most likely) or ten aperture blades was used. Handling urban nightscapes is all about proper exposure settings to get the effect one wants. The only contribution lenses might make to that is in the number of elements and what type of lens coatings are used. Typically, lenses with fewer elements (so primes over zooms) and the most recent lens coatings demonstrate the least amount of flare/reflections when used in dark environments with bright light sources in the scene. \$\endgroup\$
    – Michael C
    Commented Dec 12, 2019 at 20:47
  • \$\begingroup\$ @MichaelC that is true for tripod-bound. For handheld, the more I learn about what lens properties can make or eff up that kind of shot when taken wide open, the more complicated it seems to get ... flares, coma, oblique spherical .... \$\endgroup\$ Commented Dec 12, 2019 at 22:50
  • \$\begingroup\$ @rackandboneman The only thing handheld introduces that the same lens on a tripod would not is camera motion blur. All of those other things are there either way. Quite frankly, if shooting at apertures narrow enough to get sizeable diffraction spikes, one needs to be on a tripod even taking into account the best IS/IBIS systems currently available. Those images probably have exposures several seconds long. Look at the water... \$\endgroup\$
    – Michael C
    Commented Dec 12, 2019 at 23:34

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