5

This applies to the Sony NEX-5R, and the iPhone 5S. I want to shoot a timelapse of the sunset. The Sony manual says not to point it at the sun. Other questions on photo.SE agree with that advice, but say it's okay to shoot the setting sun.

So the question is, what counts as a setting sun? The last 1 hour before sunset? The last 30 minutes? Only when it's comfortable to look at the sun with the naked eye?

Google search says that the sun will set in my city at 6:03PM today, so when can I start my timelapse and be sure not to damage my equipment, either my NEX or my iPhone?

This is assuming I don't use an ND filter.

  • Most cameras in phones don't have an IR filter. If that is the case with the iPhone 5S then I would be very careful of using it for extended periods, even at sunset. Remember that the sensor is exposed to the light from the sun anytime you are composing a shot on the screen. – Michael C Dec 31 '13 at 5:23
  • Thanks, Michael. The iPhone 5s does include a "Hybrid IR Filter": pocket-lint.com/news/… Does that mean I should be fine? – Vaddadi Kartick Dec 31 '13 at 6:08
  • I'd still be cautious with any camera that doesn't cover the sensor to protect it until the shutter opens when the picture is being taken. To take a time lapse series you're going to leave the camera pointed the same direction between frames aren't you? Your sensor on either of those two cameras will be exposed to the sun's energy even between shots, won't it? – Michael C Dec 31 '13 at 6:41
  • Yes, the cameras will be left pointed in the same direction. AFAIK the iPhone sensor will be left exposed to the sun's energy continuously. I don't know about the NEX. Should I disable the electronic front curtain shutter? Will that guarantee that it's exposed to the sun's energy only for the duration of the actual shots and not between shots? – Vaddadi Kartick Dec 31 '13 at 8:09
  • If the screen is on and showing a Live View between shots, then the sensor is uncovered between shots. Disabling electronic first curtain only means the shutter moves to cover the sensor an instant before the picture is taken, it doesn't necessarily mean it covers the sensor the entire time between shots. I don't know if there is a way to do that or not with the NEX-5R. – Michael C Dec 31 '13 at 8:31
3

First off, let's talk about your eyes. Just because you feel no discomfort is no guarantee you are safe to look at the sun with your naked eye. From a NASA news release about safe solar viewing during an eclipse:

Damage to the eyes comes predominantly from invisible infrared wavelengths. The fact that the Sun appears dark in a filter or that you feel no discomfort does not guarantee that your eyes are safe.

If you really want to read about what happens when you stare at the sun too long, read this article from Sky and Telescope. An excerpt:

When longer wavelengths of visible and near-infrared radiation pass into the eye, they are absorbed by the dark pigment epithelium below the retina. The energy is converted into heat that can literally cook the exposed tissue. Photocoagulation destroys the rods and cones, leaving a permanently blind area in the retina. This thermal damage also occurs during extended exposure to blue and green light.

Both photochemical and thermal retinal injuries occur without the victim's knowledge, as there are no pain receptors in the retina, and the visual effects do not occur for at least several hours after the damage is done.

Now, for your cameras.

You would be much better off shooting a series of time lapse photos of the sun with a camera that protects the sensor from the energy in the light of the sun during the time between shots. Although I don't use either camera mentioned in your question, I'm assuming both use a form of Live View as a viewfinder and to compose shots.

What this means is that the sensor will be exposed to the same energy of the sun in the long intervals between shots as it will be exposed to during the short time the picture is actually taken. Here's what Stan Horaczek at PopPhoto.com has to say about it:

With a DSLR, the mirror gets between the sun and your sensor most of the time. It's only when the shutter is open that you get direct exposure and it's usually only for fractions of a second, so taking a few pictures of the sun shouldn't pose much of a problem. If you're looking through the viewfinder, though, it can certainly damage your eye, so don't linger too long.

Smaller cameras, like interchangeable-lens compacts and traditional compacts don't have the mirror for protection, though. Same thing goes for your DSLR if you have it set to liveview mode. Those cameras use the sensor to give you a preview image, so if the sun is in the frame, it's being channeled through the lens and right at your chip. It's easier on your eyes, but a lot tougher on your gear. Leave it on long enough and you could easily cause things to overheat, especially if you're shooting on a day when it's already hot out.

  • Thanks a ton, Michael, for the warning about protecting my eyes. I won't look at the sun while setting up the timelapse. Unfortunately, I don't own an SLR. Maybe I'll start the timelapse just before sunset. 15 min before? There's little heat coming in from the sun at that time, since it's winter. And I'll also make sure the sun isn't uncomfortably bright before setting up my camera. I assume that would be enough of a precaution, wouldn't it? – Vaddadi Kartick Dec 31 '13 at 14:01
  • The sun puts out the same amount of energy regardless of the season. How much is absorbed by a particular location on the Earth's surface is determined by the angle of the sun in the sky and the number of hours the sun is above the horizon. – Michael C Dec 31 '13 at 14:17
  • Saying, "Unfortunately I don't own an SLR so I'll do it like this..." might be kind of like saying, "Unfortunately I don't know how to swim but I could probably hold my breath long enough to walk across the bottom of the English Channel, couldn't I?" – Michael C Dec 31 '13 at 14:21
  • Okay, so what do you suggest? – Vaddadi Kartick Dec 31 '13 at 15:33
1

When it is comfortable to look at it with the naked eye is probably a fairly safe standard to go with. Another conservative option would be when you can take a picture of the sun without it causing the sensor to max out (it isn't pure white and you can see detail).

You can also use what is known as an ND or neutral density filter to reduce the intensity of the light to something your camera can handle safely, though you would need a very strong ND filter if it is broad daylight, but a weaker one would work as it gets closer to sundown.

  • Thanks, AJ. I edited the question to clarify that I don't use an ND filter. – Vaddadi Kartick Dec 31 '13 at 4:30
  • @KartickVaddadi - in that case, I'd go with either of my first two suggestions, comfortable to look at with naked eye or sensor is able to resolve the image fully. The later is safer, however I expect the former would be ok for most cameras. – AJ Henderson Dec 31 '13 at 4:35

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