solar photography resorces

[adrian tyler]

anyone out here got any experience with solar photography? or maybe know any good resorces regarding photographing the sun?

as always i'd be very grateful for any hints and help.

adrian

[David Luttmann]

Are you looking to photograph through standard filters such as Bayer, or are you wishing to do Hydrogen Alpha photography? Through what type of telescope?

[adrian tyler]

...well i am rather looking at discovering various possibilities, i was hoping to be able to filter and use a looooooooooong lens on my 4x5, but perhaps this is unfeasable... certainly large investmets in scientific equipment is not on my list of priorities...

[Ole Tjugen]

I did once take pictures of a partial solar eclipse, using a 360mm Tele-Xenar and a Lee IR filter with APX100 (not IR-sensitive) on a 4x5" camera...

The IR filter transmitted just enough visible light to let me use f:8 at 1 second exposure. This was pure guesswork on my part, and as the film sheet was developed in Windisch' Extreme Compensating Pyrocatechin developer, I have no idea if the exposure would be universally applicable. It was also a quadruple exposure - four exposures at 5 min intervals - with clouds moving in on the last two. But at least it's possible and might be worth a try.

[Ralph Barker]

The camera and lens choice for solar or lunar photography boils down to subject size, I feel. For each 100mm of lens focal length, you get about 1mm of solar or lunar disc. Thus, an 8" Celestron telescope (a bit over 2000mm) fits the solar or lunar disc on 35mm film, almost filling the frame. Thus, there is no real gain in using 4x5 film, as the disc size is a function of the focal length used, not the film size.

There are standard T adapters for common 35mm cameras (e.g. Nikon). Mounting a 4x5 onto the telescope is a whole different issue, and one that I haven't solved.

[adrian tyler]

thanks for the ideas, believe it or not i got some good exposures of a solar eclipse by holding my sunglasses over a sumicron and exposing at about 1000th sec!... but i'd like to try to be a bit more calculating this time.

i figured that i was going to need a long lens, my idea was perhaps to expose onto paper rather than film with the 4x5, but it seems that is not going to be feasable - a 5000mm lens is beyond my bellows extension!.

my local freindly supplier has an old 500mm hasselblad i can try linked up to a 2x converter.

how about filtering and exposure?

[Ralph Barker]

Telescope shops can provide solar filters designed for safe observational use on telescopes. These will make viewing safe for both you and the camera's internals. As Ole suggested, using an opaque (in terms of the visible spectrum) IR filter is another option, but I'm not sure where that would fall on the safety scale. Additionally, welding goggles are often suggested for viewing solar eclipses, but adapting them to use on a lens might be problematic. Naturally, exposure would be a function of the filter and film being used. Some experimentation will probably be required.

[Terence McDonagh]

You can get replacement glass for welding helmets. They come in multiple grades. I have used the darkest grade to look at an eclipse, but still didn't feel comfy staring at it. You don't know your retinas are burning until AFTER it's happened. Be VERY careful with an SLR.

[Ole Tjugen]

One nice thing about LF is that you don't actually look through the lens. I focussed on infinity without the filter, then turned the camera around and framed the shot simply by looking at the ground glass. No dark cloth was necessary - I just needed to line up the sun where I wanted it or the start of the sequence. Then I closed the shutter and put the filter in place.

[GPS]

I use the Thousand Oaks optical polymer filter (gives almost natural Sun's color) and my 800mm Nikon lens. The pictures magnified to 70mm of the Sun's diameter on paper show clearly sun spots ect. You can Google sites for Sun's exposure and other details.