Here is the shot, taken off Reddit: Image of moon, with Venus and Mars As you see, the moon has a perfectly exposed shadow (you can see the details in the unlit side of it) which I want to achieve. I understand you want to have a longish exposure time, however whenever I try to take a photo like that, I just get an overexposed crescent, and the rest is black. How would I do something like this then? Is there a specific time of day (during a twilight period or something?) or month? What about Photoshop?

Additional question, how is the starburst achieved with the planet Venus? Would the photographer have used a starburst filter on their lens or just used a slow aperture (which I doubt because it's nighttime).


2 Answers 2


The "shadow" area of the Moon is lit by Earthshine - light reflected towards the moon from the sunlit part of the Earth. From the Moon's point of view, the more of the earth that's sunlit, the brighter the earthshine is.

If you think about the Sun-Moon-Earth geometry, the thinner the crescent moon is as seen from Earth, the larger the lit area of the Earth gets as seen from the moon. So the thinner the crescent, the better lit the "shadow" part of the Moon is.

So try taking shots with the thinnest crescent you can manage. And keep increasing the exposure until you see some detail in the shadow area - that can be a LOT longer than a normal moon photo.

It's possible the image you've picked might be a composite - sometimes the lit part of the moon is so overexposed it bleeds into surrounding pixels and looks noticeably fatter than the rest of the moon. Or the shadow brightness may have been boosted in post processing.

Not sure about the Venus starburst - it might be from a lens with a 7 bladed aperture iris, or, as you suggest, a starburst filter (though 4 or 8 ray versions are probably more common). This is one of the things that makes me think the image might be a composite - if you look at the length of the rays from Venus, then you'd expect the light from the brightly lit part of the moon would be spread out by a similar amount, and that doesn't appear to be happening. (It could also just be that Venus, being closer to the sun and with more reflective clouds, is actually brighter than the dark gray moonrock, so the fact that both venus and the brightly lit moon are both maxed out in the photo is misleading - in reality, venus may have a higher surface brightness, producing brighter and longer diffraction spikes.)

  • \$\begingroup\$ I have done something similar, and the only way to get a reasonable image is to make a composite, I.e. an HDR image. \$\endgroup\$ Commented Jan 8, 2018 at 5:49
  • \$\begingroup\$ I counted 14 on the starburst, so my guess is a 7 bladed aperture stopped down. \$\endgroup\$
    – Calyth
    Commented Jan 10, 2018 at 13:47
  • \$\begingroup\$ @JimGarrison No composites/HDR necessary \$\endgroup\$
    – Michael C
    Commented Jan 12, 2018 at 6:26

Both the earthshine details on the moon and the venus star burst can be achieved by setting a very narrow aperture like f22 and going for a long exposure. If a wider aperture is used, you will get only a circular bright mass.


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