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Context: I find myself due to be in the path of the upcoming annular solar eclipse. This was unplanned and I am unable to get a proper filter delivered on time.


The general consensus on the internet appears to be that photographing an eclipse requires a solar filter, or at least a 16 stop, ND 100,000 filter, e.g.: https://www.bhphotovideo.com/explora/photography/tips-and-solutions/how-to-photograph-a-solar-eclipse

But it seems people frequently take photographs under a normal sun without apparently needing such extreme levels of filtering. Perhaps such advice is geared towards people trying to fill the frame with the sun using a super telephoto lens? It feels intuitive that aiming a telephoto lens directly at the sun would be more dangerous, like starting fires with a magnifying class.

So what I am wondering is, if I were to take a landscape photo with a mild telephoto lens (e.g. a 85mm), with an eclipsing sun in a corner, do I still need the recommended protection? Or would a 10 stop, ND 1000 filter be sufficient?

Would this be different with 35mm or wider lens?

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When using a solar filter and properly exposing to see details on the sun's surface, the only thing that is going to show up anywhere in the frame is the sun. Notice that there are no stars visible in any filtered images below.

enter image description here
About an hour before totality as the Moon's silhouette is just beginning to move in front of the Sun. A solar filter was used with a 200mm lens (the image is heavily cropped to about a 900mm angle of view on a FF camera) on a 20MP APS-C camera. ISO 400, 1/500 second, f/5.6. The filter is providing about 15 stops of attenuation not only of visible light, but of infrared and UV as well.

Everything else will be entirely too dark. If you want to take photos of the landscape during an eclipse, you won't be able to use a solar filter unless you use exposures in the minutes-long range.

This unfiltered image was taken about two minutes before totality. ISO 1600, 1/100, f/4 That's EV100 = 7, about the same brightness as brightly lit nighttime streets or a stage show. In full direct sunlight the scene would have been about eight stops, or 256X brighter!

enter image description here

During a total solar eclipse one can safely image the Sun's corona without a solar filter. The light from the Sun's corona is much dimmer that the surface of the Sun itself. enter image description here
Unfiltered. ISO 400, 1/500, f/5.6 (EV100 = 12, about the same exposure settings one would use for a subject in full shadow on a sunny day.)

Below is an unfiltered image of the "Diamond Ring" that is visible just as the very first speck of the Sun's surface becomes visible after totality ends. Notice that the exposure is bright enough to see a bright star, Regulus in the constellation Leo, to the upper left of the Sun.
enter image description here
Unfiltered. ISO 1600, 1/125, f/4 (EV100 = 7). FF camera at 105mm (cropped)

On the other hand, when enough of the Sun's limb is visible to see the "Bailey's beads", the sun is much too bright to be imaged without a filter. Below is a filtered shot taken just 24 seconds after the "Diamond Ring" image above! Most annular eclipses will be much brighter than this for the entire event.
enter image description here
Filtered. ISO 400, 1/500, f/5.6 (EV100 = 12 with a 15 stop filter! That's EV100 = 27.) The exposure settings plus solar filter were 20 stops dimmer than the "diamond ring" shot.

So what I am wondering is, if I were to take a landscape photo with a mild telephoto lens (e.g. a 85mm), with an eclipsing sun in a corner, do I still need the recommended protection? Or would a 10 stop, ND 1000 filter be sufficient?

A ten-stop ND filter would probably make things worse. Why? Because many ND filters only attenuate for visible light wavelengths and do not attenuate infrared wavelengths, which is where most of the damage the sun can do will come from. With a ten-stop ND filter, you'll expose for ten time longer, thus subjecting your camera to ten times as much of the Sun's infrared energy!

Personally, I wouldn't include the sun when it is more than a few degrees above the horizon in any frame when using a 50mm lens, much less an 85mm.

It's usually fairly safe to photograph a scene containing the sun using a wide angle lens, say 35mm or wider on FF body, when using a DSLR or other camera that only exposes the sensor or film during the actual exposure. For mirrorless cameras, though, the sensor is almost always exposed just as it would be for a very long exposure and more care must be taken with regard to the sun.

As the focal length increases, more of the sun's energy will be collected by the lens. This means more potential for damage.

enter image description here

enter image description here

Not only can you damage your camera and/or lens, but you can also permanently damage your vision if using an optical viewfinder!

The links embedded above point to other questions we've had here at Photography SE that address most of your concerns. Let us know if you still have questions after reading them.

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  • Personally, I wouldn't include the sun when it is more than a few degrees above the horizon in any frame when using a 50mm lens, much less an 85mm. This is the the bit that I was interested in. I'm aware of the risks but I was curious how short a focal length they apply down to. Pity that there isn't more concrete information on this; I'd think people could calculate it. I ended up finding a local store with a piece of solar film, but I'll take your word for it on this. Thanks. – Semaphore Jun 21 '20 at 12:37
  • @Semaphore Part of the reason no one knows is that I can't recall seeing any camera company ever say it is OK to point a camera at the sun, no matter what the focal length is. – Michael C Jun 21 '20 at 15:36
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Yes, the (very strong) ND filter is needed only when shooting at the sun with a tele lens (which is what people are usually interested in during eclipses). It protects the camera & lens by keeping most of the light out.

But as you noted you can take picture of the sun in the sky without an ND filter (it is even frequent with wide-angle lenses), so you wouldn't harm your lens but in normal conditions the exposure time of such pictures is short. During an eclipse to get a sufficiently exposed landscape, you would need a long exposure with a very bright spot somewhere and this could harm your sensor. So it could depend on how annular the eclipse is and how long an exposure you need.

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  • To clarify, you're saying I don't need any filter at all if using a 85mm lens in sun's direction? Or to use a ND1000 one but no need for ND100,000? I'm not sure what qualifies as very strong in this context. – Semaphore Jun 19 '20 at 9:59
  • You don't need one for a regular sunny day, what makes you think you need one when there's hardly any visible sun at all - unless you're actually zooming right in at the sun itself? – Tetsujin Jun 19 '20 at 10:04
  • @Tetsujin I'm usually not photographing the sun itself during normal landscapes though, at least not outside of sunrise and sunsets. For an eclipse I'd like to include the sun into the scene, both during and before/after the event, albeit not zoomed. Hence the question. – Semaphore Jun 19 '20 at 10:12
  • If you want to shoot the dark landscape you can't use a ND filter. See augmented answer. – xenoid Jun 19 '20 at 10:12
  • ND filters are not enough, as they do not usually attenuate the Sun's infrared energy, which is what does the damea to cameras and lenses (and retinas). One needs a solar filter that also reduces infrared by the same amount as visible light. – Michael C Jun 21 '20 at 15:38

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