Interesting! My assumption is that this could not happen with a phone camera though, correct? Because then one would think just leaving one's phone face down on the table in sunlight would ruin it.
The sun would have to be dead center middle so it's probably unlikely. The lenses on the fancy cameras definitely make it a far worse problem for them vs our phone cameras though.
An iphone 6 camera only costs 5$ and is easy to replace(with a screw driver and spudger (maybe an igizmo) most hacker news people likely wouldn't have issues.), so it's not the end of the world (source:I repair phones)
Most people don't mount their cell phones to tripods or celestial tracking mounts so there's enough movement it would never be an issue. It would be interesting to mount one to a celestial tracking mount and see what happens. Honestly, I've got some old cell phones laying around here and might just give that a try.
That would be really cool to see! /u/tzs posted some links, so it looks like people a somewhat unsure. I'm guessing that if the sun is well tracked in the center for long enough that it would damage the lens. I guess we don't have a ton of hard data for it.
So I've photographed lasers a bunch and burned a few sensors, I guess I should toss in my experience. As far as I can tell, it really depends on the specific phone that you're using, and also the damage is usually fairly minimal. I've damaged fancy sensors with lasers and they almost always have major problems afterwards, but for years I used a phone with a very severe amount of laser damage to the sensor and the photos were quite good and the damage was barely noticeable (as a series of black lines on the image.) There was no damage to the lens.
I also doubt it would be the lens damaged in the case of a smartphone. The lenses are built to take a tremendous amount of abuse and almost certainly would be fine. The sensors are by far the more fragile component.
The most common expert opinion seems to be that photographing the Sun with a smartphone camera won't damage it. Here's a NASA document on this: [1]
A Chicago Tribune story [2] cited the WSJ [3] saying that Apple said that eclipse photography would not hurt an iPhone.
Forbes says that recent generations of iPhone have sensors and lenses just big enough to cause damage if you point them at the Sun for more than a couple seconds, but that selfies that include the Sun are fine because the front camera and sensor are small [4].
>Forbes says that recent generations of iPhone have sensors and lenses just big enough to cause damage if you point them at the Sun for more than a couple seconds, but that selfies that include the Sun are fine because the front camera and sensor are small [4].
i don't buy it. phones get their rear cameras pointed towards to the sun all the time. all it takes is you putting the phone on its back out in the sun. you'd be hearing thousands of reports iphone cameras mysteriously getting damaaged. not to mention that it's not really forbes saying that, it's some blogger that forbes sold its name to (a practice they're infamous for)
Not really, the light flux is not really related to the physical aperture (diameter of the lens), but rather to the f-number of the lens (what photographers usually call "aperture" is in fact the f-number, focal length divided by lens aperture), an iPhone has an f/1.7 lens. This is an extremely fast lens, faster than any any zoom on a DSLR. Only dedicated prime lenses are faster.
The flux is:
Φ/4α² * 1/A²
Total energy does depend on actual aperture though. Total power is:
Φ/4πα * D²
Where D is a diameter of the lens.
As a first approximation, the sensor can support a certain flux, but once that regime is exceeded the damage is proportional to the energy, not to the flux. So if we talk about the regime where the sensor is not destroyed, flux is the relevant metric, but a larger lens will likely cause more damage once damage actually occurs.
This is just theoretical pontification, but I think there is a respect in which size matters: heat dissipation. Suppose you have a sensor laminated to a heat sink. If you apply some flux density (power per unit area) to a very small area (as would happen with a phone camera), you can dissipate heat in three dimensions: back toward the heat sink and to the sides through the rest of the sensor. If, in contrast, you apply the same flux density to a large area, the edge effects matter less and you approach the limit where heat only dissipates straight back. This could have a dramatic effect on the temperature.
A similar effect happens in the kitchen. It's very easy to burn yourself by touching a large hot surface, but it's much harder to burn yourself by touching a hot pointy thing.
An iphone 6 camera only costs 5$ and is easy to replace(with a screw driver and spudger (maybe an igizmo) most hacker news people likely wouldn't have issues.), so it's not the end of the world (source:I repair phones)