Solar photography

Hi.
I would like to take photos of the solar eclipse on february 26. I bought a solar filter (Thousand Oaks Optical) but i'm sure this will be delivered before february 26 ...
Is there any other way to take photos of the sun ?
Is it possible to use "x-ray plates" in front of the lens to take photos? I know this will not get the same quality as a real filter for solar photography ...
Spanish is my natural languge, i don't know if "x-ray plates" is the correct translation ...

Heya,

I would not use simply dark plates, ND filters, nor welding glass, or whatever x-ray plates are. None of those block IR/UV and that's what you need to block or you will cook stuff. IR/UV rejection reflects heat instead of absorbing it.

Look for some Baadar Astro Solar Film and you can cut it and stretch it over a lens or lens cap with a hole cut, or buy a little frame to put it in.

Astrozap makes some premades for less than $50.

Not sure where you are to buy local.

You can photography the eclipse at totality without a filter, but only during totality. If it's a partial eclipse, don't try that without a filter.

You need a proper filter to be safe. Both for your eyes and your camera's sensor. Don't just use dark glass.

Very best,

The last eclipse I photographed I had such a filter as MalVeauX explained however it was made especially for a 8" Celestron SCT scope . That will give you a white image . Also you can take a roll of 35mm 400 speed or 200 speed film , expose it to bright sunlight and cut 6" strips and then take a shoebox top and cut a 4"x4" hole in the lid and tape the exposed film across the hole and use it as a viewing hole . I also placed this lid in front of my 400mm lens and took pictures of the eclipse . Gives a different color to your image but heck at least you can image the eclipse this way . Just never look through the lens unless the film is placed over the front of the lens . Look on my flickr site and see some examples :

https://www.flickr.com …/album-72157629985457684/

Thank you MalVeaux, i didn't know about blocking IR/UV ... i will not experiment. I'm in south america so it's almost impossible buy something now (let's say in US, Europe) and get delivered before the eclipse ...
And of course i never look the sun directly thourgh the lens, i know you can harm your eyes.
Thank you !!

Thank you !! I like the idea of using film, i'll try to find some on a store

Remember if you try the film use 35mm roll film in 400 (400 is best) or 200 . Take the roll outside , grab the film edge and pull it out of the roller and expose it in sunlight for a couple minutes to be sure it's all exposed before you look through it . Also when you tape the film to a shoebox lid be sure to overlap the edges so that the holes on the sides are completely covered up . It's advised not to use old film negatives that has been used for picture taking and the reason is cause an image is on the negative making the film unsafe but a roll of film not used already for taking pictures is ok if you expose to sun first as I mentioned , hold it up so the sun can expose it all it comes out even with total coverage .

I bought a 200 asa 35mm film (i'll try to find 400). I will follow your steps to photograph the sun.

Is this photo taken with the film? https://www.flickr.com …/album-72157629985457684/

And what about this? https://www.flickr.com …/album-72157629985457684/

Thank you for your help!

The first link was taken using the camera film that I exposed to the sun then taped over a 4x5 hole in a shoebox lid . The second white image was taken with my scope using a Baadar filter made for my scope .

The camera film will be over powered by the reddish tint caused by the film as you see in the first linked image . So don't expect to have a decent FG image look . It will be exactly like mine .

Malveaux is right that any filter must block the IR and UV as well as the visible light. It used to be fairly simple as to what was safe and what was not. But now there are variations of things like x-ray film and welders masks. Some are safe and some are not and it's not obvious which is which, so a blanket "don't" is the safest option.

If you are going to use film, it must be silver based, not dye based. ie. Not color film. Unless you know for sure that it's silver based, don't use it.

If your solar filter doesn't arrive in time, I'd suggest using a pinhole projection setup. It works really well, is 100% safe and many people can view it at the same time. We found about a 1mm hole works well. Make sure the hole has a good clean edge and project it onto a white card that is in the shade.

Steve.

^^^^^^^ I know for a fact that the camera film I mentioned can be used and does work cause I have done it and have images to prove it . Granted it does not produce the best image but it will work . Me and my wife both have used this technique and have never had eye problems .

But your photo taken through film is at sunset when you can pretty much look at the sun with sunglasses anyway. Any book on the subject explicitly states that color film does not block IR. In fact, exposed color film is used for slave flash triggers because it does block visible light and passes IR.

Because you and wife aren't aware of any harm doesn't make it fact. Especially when it contradicts the advice and information published by NASA's eclipse expert and a Professor of Opthamology who have explicitly studied what is and isn't safe.

You are simply wrong. Please stop telling people to do something that could cause them harm.

Steve.

SteveInNZ wrote in post #18283882
But your photo taken through film is at sunset when you can pretty much look at the sun with sunglasses anyway. Any book on the subject explicitly states that color film does not block IR. In fact, exposed color film is used for slave flash triggers because it does block visible light and passes IR.

Because you and wife aren't aware of any harm doesn't make it fact. Especially when it contradicts the advice and information published by NASA's eclipse expert and a Professor of Opthamology who have explicitly studied what is and isn't safe.

You are simply wrong. Please stop telling people to do something that could cause them harm.

Steve.

Whether it's at sunset or high in the sky is no difference . I've done both and have had no problems . Even had some neighbors look through the film also and they had no problem AND the film I used was Kodak 400 color film . I never told anyone they should do it , I told them it can be done and I have done it and I have used it for imaging the eclipse . I don't need a professor to tell me that it is not safe . It's not something I do everyday and at the time I learned that it could be done that way I learned it from the Sky & Telescope magazine website back in 2012 when I did it that way . Maybe film has changed since I did it back then but what I used was the old film and it worked . If I had gotten harmed I would not have mentioned it but I didn't and that's that . Have a good day SteveInNZ .

I will add tho I have also tried a welders glass and even tho some use to say that was safe I don't recommend it cause I have looked throught welder glass for a very short time and the effect is different and I do not recommend welders glass .

I wish I could find the right YouTube video to offer a link. I think it was a recording of Dr. Chou from the School of Optometry at the University of Waterloo -- describing the issues of eye safety when viewing the sun.

The main points were that the amount of time you can stare directly at the sun without damage to your eyes varies by individual but is mainly based on how small your pupils can constrict. Younger children tend to be able to constrict their pupils to smaller sizes and you lose this ability as you age. So a fully grown adult might (and I have to re-emphases "might" because everyone is different) have permanent damage after only 40 seconds... but a young child might get away with nearly double that time.

The "problem", however, is that the eye wont experience any pain as the damage is done. He explains that if you go in for eye surgery, you'll be given something to immobilize your eyes so that your eyes wont move during the procedure, but they don't actually give you anything for pain because you have no nerves that feel pain.

He also explains that the damage isn't immediately noticed. Once the damage is done, it can take anywhere from 24-48 hours before the retinas stop functioning. He explains that you might view the sun, think you are fine when the event is over, go to bed, and wake up the following day (or possibly the day after that) and realize suddenly that you don't see so well anymore.

To view the sun "safely" you need to block out a minimum of 99.997% of all the Sun's energy... and that INCLUDES a considerably amount of energy in the infrared spectrum that you can't even see... but will still damage your retinas.

A "safe" solar filter typically blocks 99.999%. That translates into 1 photon of light (regardless of wavelength) out of every 100,000 makes it through the filter.

I often hear people mention using welding goggles. The issue here is that welding goggles come in many different grades. Once upon a time they were smoked glass. Today they're often modern polymers and the filters are designed to block the wavelength light emitted by the type of welding torch (which varies depending on the type of welder). These filters do not universally block the full visible spectrum plus the IR spectrum adequately to protect the eyes.

I just looked at an ad on Amazon -- someone selling 10-stop welding goggles for eclipse viewing. 10 stops is ABSOLUTELY NOT SAFE (10 stops works out to 99.9% and you need a minimum of 99.997%. While this might seem trivial because of how it's presented as a decimal value... it's actually more than 100 times more light than is safe.) A "safe" solar filter will have an optical density of 5.0 (each 0.3 is 1 photographic "stop" - so that works out to 16.67 stops - but these aren't just stops in the "visible" spectrum, they also block the IR spectrum.)

I often tease my audience with the caution: "Do NOT stare DIRECTLY into the Sun with your last remaining working eyeball!" (and they usually laugh)

I can't say you "will" go blind, but the risk of non-reversible damage (including blindness) is extremely high and it's just not worth the risk when there are relatively cheap things you can do to guarantee you wont have that outcome. I order some solar filters to hand out in "bulk" quantities and in these high quantities they're about 60 cents each. If I ordered them in even higher quantities I could get that down to less than 50 cents each. But even if you buy just one pair of eclipse viewers for $2... that's still really cheap insurance against the alternative of having your vision screwed up for life.

There is also some (false) assumption that once the sun is partially eclipsed that it is safe to view. It is NOT safe until it's fully eclipsed. Suppose the Sun is 90% blocked by the moon. That doesn't mean it's only 1/10th as bright... that means the remaining 1/10th of the sun is just as bright as it ever ways (because the moon is blocking that section at all) ... it's just projecting onto a smaller area of your retina (so you're destroying the retinas in a smaller area of your eye instead of a larger area of your eye, but you're still doing the damage.) Remember that your eye actually is "focusing" a sharp image of the sun onto your retina.

https://eclipse.gsfc.n​asa.gov/SEhelp/safety.​html

https://eclipse.gsfc.n​asa.gov/SEhelp/safety2​.html

Thank you very much, it's really good to know all these information!

TCampbell wrote in post #18288796
I just looked at an ad on Amazon -- someone selling 10-stop welding goggles for eclipse viewing. 10 stops is ABSOLUTELY NOT SAFE (10 stops works out to 99.9% and you need a minimum of 99.997%. While this might seem trivial because of how it's presented as a decimal value... it's actually more than 100 times more light than is safe.) A "safe" solar filter will have an optical density of 5.0 (each 0.3 is 1 photographic "stop" - so that works out to 16.67 stops - but these aren't just stops in the "visible" spectrum, they also block the IR spectrum.)

So are you going to contact Amazon and tell them what you just explained here ? I feel your obligated to do so since you did find them on Amazons website .