Exposure for the sun

[Eric De Santiago]

Has anyone here tried to photograph the sun’s surface? I’m curious as to what exposure it would need.

 

[Luckless]

Due to the high levels of UV and IR light, photographing the sun with standard photographic tools is extremely dangerous and not remotely advised. Even some 'purpose made' gear is sketchy and comes with rather high risks. - Be VERY wary of pinholes!

You really need to use the proper tools purposed made for solar astrophotography, and getting more detail than a washed out blob is a rather non-trivial task.

 

[RalphLambrecht]

Has anyone here tried to photograph the sun’s surface? I’m curious as to what exposure it would need.

google for solar eclipse photography;there is data even from NASA for this.

 

[Sirius Glass]

This is a good way to go blind or burn a hole in the shutter if the right filters are not used. Be very careful.

 

[Paul Howell]

Make sure you buy from a dealer who sells filters that have been certified. There are lot of poorly made and not safe solar filters on the market, left over from the last ellipse that show up on ebay.

 

[jim10219]

There is no good way to work out the exposure for a solar photograph that I have found using traditional analog means. A lot depends on the filter you use, the position of the sun in the sky (both time of day, season, and latitude), the pollution, the elevation, etc. Really and truly, the best way to do it, is to use a digital and take a few sample shots under the same (or similar) conditions. Then you'll get a number you can start from. So if you're going to shoot a solar eclipse, try it out a few days before on a digital at around the same time and with the same filters and everything and see what works. This is also helpful because it gives you the opportunity to do some dry runs for switching out gear or tracking the sun through the sky.

Luckily, I've found that when photographing the surface of the sun, exposure times aren't super picky. If you overexpose or underexpose it a bit, you can still get a usable photograph. What is important, is that you use a proper filter, and use it over the front of your lens. The lens will intensify and focus the rays of the sun, and without a proper filter, you could catch your whole camera on fire!

I made my own filters out of Baader solar film, PVC pipe, tape, and some thumb screws with rubber tips. They fit any of my lenses, and they were a lot cheaper to make than buying premade solar filters.

 

[RalphLambrecht]

This is a good way to go blind or burn a hole in the shutter if the right filters are not used. Be very careful.

the safeat way is probably to built a pinhole tube and photograph the projected image.

 

[RalphLambrecht]

There is no good way to work out the exposure for a solar photograph that I have found using traditional analog means. A lot depends on the filter you use, the position of the sun in the sky (both time of day, season, and latitude), the pollution, the elevation, etc. Really and truly, the best way to do it, is to use a digital and take a few sample shots under the same (or similar) conditions. Then you'll get a number you can start from. So if you're going to shoot a solar eclipse, try it out a few days before on a digital at around the same time and with the same filters and everything and see what works. This is also helpful because it gives you the opportunity to do some dry runs for switching out gear or tracking the sun through the sky.

Luckily, I've found that when photographing the surface of the sun, exposure times aren't super picky. If you overexpose or underexpose it a bit, you can still get a usable photograph. What is important, is that you use a proper filter, and use it over the front of your lens. The lens will intensify and focus the rays of the sun, and without a proper filter, you could catch your whole camera on fire!

I made my own filters out of Baader solar film, PVC pipe, tape, and some thumb screws with rubber tips. They fit any of my lenses, and they were a lot cheaper to make than buying premade solar filters.

safety should be your first and money your last priority with solar photography.

 

[jim10219]

safety should be your first and money your last priority with solar photography.

Baader makes high quality filters of all kinds and are well respected in the astronomy field. If they're safe enough for professionals to trust for prolonged direct viewing of the sun through a high powered telescope, they're safe enough for your camera. They also sell solar film directly, so you can custom make your own size, because they know a lot of hobbyists make their own telescopes, so they'll need custom filters anyway. So you see, neither safety nor money have to be prioritized if you DIY.

They also sell premade filters, if that's your thing. They're certainly not any safer, but they do save you the step of DIY as the cost of a few bucks.

 

[Dr. no]

OR, if you do your own processing (esp LF/MF) use the unexposed but developed film leaders. These are dense, and contain a UV filter, and are actually one of the safe filters to use for viewing eclipses (I actually use a double layer for that, and would for the sun also)

 

[Alan Edward Klein]

Has anyone here tried to photograph the sun’s surface? I’m curious as to what exposure it would need.

To avoid clipping, shoot at night.

 

[Andrew O'Neill]

To avoid clipping, shoot at night.

How would you photograph the sun at night??

 

[MattKing]

How would you photograph the sun at night??

With your tongue firmly in your cheek?

 

[Andrew O'Neill]

With your tongue firmly in your cheek?

 

[Alan Edward Klein]

With your tongue firmly in your cheek?

Yes. Another requirement. Thanks for reminding me.

 

[Sirius Glass]

With your tongue firmly in your cheek?

But do not bite down hard!! Do not ask me how I know!

 

[NedL]

I've used the Baader film as well, on an old 500mm lens ( the kind with "donut-ring" shaped flare artifacts... ), I used the kind made for viewing with your eyes and it worked just fine ( they also have a kind for photography, which isn't safe to look through with your eyes ). During an annular eclipse, I cheated and stuck it on a digital camera first to get an idea of the exposure, then swapped it back to the F3 ( the F3 was WAY better.... couldn't get the focus right on the digital camera... at least not without taking more time than I wanted from viewing the eclipse myself ). Can't remember what the exposure was but something like F/8 and 1/8s or maybe 1/4s. As others said.. be hyper-paranoid-careful about pinholes and always inspect the filter carefully by holding it up to sunlight and checking. With this kind of filter you can see sunspots and maybe a few filaments and plages, but not other features like spicules and prominences ( which might be what you are thinking of when you think of the sun's surface ) I've also got a small solar telescope with a hydrogen-alpha filter. Through the eyepiece photos are possible but difficult due to the short eye relief. I've only used digital with the telescope.

I watched the transit of Mercury with it a few years ago, and the transit of Venus before that

Transit of Mercury par Ned, on ipernity

These telescopes made by Coronado are not terribly expensive and the views of the sun are incredible. We've been in the solar minimum for a few years now and it's not very active these days. There is another transit of Mercury coming up very soon in November. The next one won't be until 2032.

 

[FotoD]

if you do your own processing (esp LF/MF) use the unexposed but developed film leaders. These are dense, and contain a UV filter, and are actually one of the safe filters to use for viewing eclipses (I actually use a double layer for that, and would for the sun also)

Has anyone tried this? Does the type of (B&W) film matter? How many sheets of film does it take? They don't all have a UV filter, do they? But I guess you could stack a UV filter as well.

 

[Chan Tran]

The sun would appear very small what is the sun diameter in degrees angle of view? I guess it's like 1 degree or so right?

 

[guangong]

Down the road from my house is a major dealer in astronomical telescopes. When first opened, on weekend nights a very large telescope was erected in parking lot for locals to look through. I recall that even looking at the moon with that instrument required special filters in order to protect the eyes. And that is reflected sunlight. Safely taking a picture of the sun requires a great deal of preparation, and even more caution.
Astronomers and physicists take pictures of sun for reasons other than pictorial interest.

 

[gone]

I would guess that you should be on top of Mauna Kea or somewhere like it to get through the pollution and haze.

 

[reddesert]

You can use a filter made from Baader solar filter film over the objective (meaning in front of the lens/telescope, not behind the eyepiece). Only buy it from a reputable dealer that sells photographic or astronomy stuff. B&H sells a piece of Baader film that is about 5.5x6" for $19, but they're out of stock at the moment; other dealers may have some. The film tends to sell out just before eclipses I think, so plan ahead. This small piece of filter film is all you need to make several filters, because you can mask down the lens (make an opaque mask for the front leaving only an inch or so open, put filter material in that inch opening).

Developed black-and-white film leader (from silver film, NOT C-41 B&W) has long been recommended but it varies a lot in density and is not as dense as real filter material, so I recommend against it for viewing with the eye. The UV and IR opacity comes from the metallic silver in the developed film; but I have seen developed film leader that allows you to dimly see daylight scenes, which is not nearly dense enough to look at the sun. You can try using it for photographic purposes since you're only risking equipment. Again, mask down the lens to a smaller aperture as needed.

Even with the solar filter, you can damage equipment if you aren't careful. While preparing for the 2017 eclipse I tested using a telescope with a solar filter to do eyepiece projection onto a screen, and nearly melted the plastic eyepiece housing.

The Sun's image subtends half a degree, which is pretty small; you need a telescope or long lens to see detail. For the 2012 annular eclipse I made a pinhole camera with a six foot focal length (~ 1800 mm) out of a ski box. This worked pretty well for educational viewing to carry around and show people, but the image is still barely 15mm across and with a pinhole of 0.5-1mm, you only get resolution of ~1mm due to pinhole size and diffraction.

 

[Luckless]

Concentrated UV and IR are not things that you really want to mess around with, especially if it is going anywhere near your eyes.

Unless you have the equipment and training to measure the broad spectrum UV passing through a homemade filter, and properly measure its failure rate, then spend the money on the Baader solar filter or other brand as supported by the astronomy community.

And always carefully inspect before use.

 

[Wallendo]

If using a SLR, pick up a solar filter (I bought one before the last eclipse). Point the camera in the direction of the sun. Use a piece of paper or cardboard behind the viewfinder to view the image (don't look through the viewfinder). Bracket heavily.

Only if you are sure there are no leaks should you look though the viewfinder.

To be honest, the best way to do this is a digital camera with live view and a histogram representation. If something goes wrong, you lose a sensor, not your vision. If you want analog images, you can use the digital camera to determine exposure, and then move the filter to an analog camera.

 

[Luckless]

you can use the digital camera to determine exposure, and then move the filter to an analog camera.

And remember to point the camera in another direction before removing the filter... One of those "Small but important order of operations" things.