4
\$\begingroup\$

We know that taking photo of the sun can cause some degree of damage to the camera and our eyes. So, are there any damage to the camera (point and shoot / DSLR) when taking photo of the moon and/or stars at night? (Because the moon gets the light from the sun.)

\$\endgroup\$
4
  • 3
    \$\begingroup\$ With regards to the moon getting light from the sun, so does every daytime outdoor (non artificially lit) shot and they're far brighter than the moon \$\endgroup\$
    – Dreamager
    Jun 12, 2012 at 11:47
  • \$\begingroup\$ @Dreamager Well, no, they're not. The Moon is in direct, unfiltered sunlight (on the bright side). The atmosphere costs at least one stop, even at a tropical noon, for scenes on Earth. The only way Earthly scenes can be brighter is if they have a significantly higher albedo than the Moon, which is the color of worn asphalt pavement, similar to an 18% gray card. Beaches, snowscapes, and light colored walls or fences in direct sun will be brighter, but general scenes aren't. \$\endgroup\$
    – Zeiss Ikon
    Apr 7, 2020 at 19:09
  • \$\begingroup\$ @Zeiss Ikon - But the Moon light reflection passes through the same filtering atmosphere to reach the Earth. \$\endgroup\$ Apr 7, 2020 at 21:02
  • \$\begingroup\$ @user10216038 That's why it's Sunny f/16 rather than Sunny f/22. \$\endgroup\$
    – Zeiss Ikon
    Apr 8, 2020 at 11:06

4 Answers 4

12
\$\begingroup\$

The light from such objects is nowhere near bright enough to cause damage to the sensor, however using really long exposures to capture dim distant stars could damage the sensor by overheating.

Most modern DSLRs have heat sensors and cutoffs to prevent this, but if you're using an older camera and keeping the shutter open for hours with an external power source I imagine you could do some damage!

I'm not trying to be alarmist, but I would recommend a series of short exposures (less than one minute) with cooloff time in between for the best results. Multiple exposures can then be stacked in software to reduce noise. Unless you have a tracking mount you'll get star trails with longer exposures so that's another bonus of short exposures.

\$\endgroup\$
6
\$\begingroup\$

The moon is not anywhere close as bright as the sun (it's basically a giant diffuse, grey reflector), and so there is little risk. According to Wikipedia, the full moon at its brightest is about 400,000 times dimmer than the sun. That's 18 1/2 stops!

However, the moon does tend to get overexposed in photographs, since it's hard to fill the frame without a really long lens and space is really dark. As such it's best to shoot in manual mode or bring exposure compensation way down.

\$\endgroup\$
2
  • \$\begingroup\$ ...or use spot metering on the moon. That's how I do it. \$\endgroup\$
    – bwDraco
    Jun 28, 2012 at 1:50
  • 1
    \$\begingroup\$ The Moon is in direct sunlight, and is pretty close to an 18% gray card, so Sunny 16 rule works for photos of the Moon. If you're using a telescope, don't forget to adjust your f ratio for any added magnficiation (from, say, a Barlow lens or eyepiece projection). \$\endgroup\$
    – Zeiss Ikon
    Apr 7, 2020 at 19:05
5
\$\begingroup\$

This is a repeat of

https://physics.stackexchange.com/questions/25825/can-you-damage-your-eyes-viewing-venus

No, there cannot be any damage, not to the camera and not to your eyes either.

In the case of the moon and/or planets, there is not enough brightness to cause any damage, and the lens cannot increase the surface brightness. In the case of the stars, they are never more than a single point of light, so even with the largest telelens the brightness is too low to damage anything.

\$\endgroup\$
0
\$\begingroup\$

I assume that your question is based on the idea that a lens concentrates light. That way, any light source could be concentrated into an area small enough to make that area exceed combustion temperatures. The good news is, according to XKCD: lenses do not concentrate light.

Except lenses don't concentrate light down onto a point—not unless the light source is also a point. They concentrate light down onto an area—a tiny image of the Sun.

https://what-if.xkcd.com/145/

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.