Rofflesaurrr said:
I plan on photographing the upcoming solar eclipse this month from NJ. My longest lens setup just happens to be a Canon FD zoom. I have a 100-300mm f/5.6L and 2x-B extender. This will give me a 600mm effective focal length at f/11 wide open.
The advices given for digital cameras are valid for film cameras as well, you can look at the thread http://www.canonrumors.com/forum/index.php?topic=32433.0
I shot the August 1999 eclipse using an A-1 and a 70-210mm/4.5 + 2x, f/11 may make focusing a bit hard using the standard screen, IIRC the AL-1 screen was not much different. Also, you're shooting at full aperture when the image quality is not yet at its best. It could be better to shoot at 300mm without TC, stop down 1-2 stops, and then enlarge and crop when printing.
For any Sun photo outside a total eclipse, a Sun filter is needed, other DIY systems are just dangerous, especially on a clear day and the Sun high in the sky (when almost nothing filters it even a little). Sun filters block UV and IR, letting pass just a small percentage of the visible light.
The filter need to be mounted on the lens, in front of it. Filters mounted to the rear are today deemed very dangerous because the lens will collect and focus the energy on the filter, and the heat can break it (and also damage things around...).
A slow film will have better definition (useful when the Sun shows spots or the like), but when you have to shoot through the whole atmosphere, there's the issue of turbulence which may decrease image quality, especially on hot days, or where temperature differences may create more turbulence.
Using faster shutter speed may "freeze" it, and deliver better images, especially if the Sun shows some features like spots (some appeared lately, although the Sun is at its minimum of the 11-year cycle). I would try to avoid going below 1/125, especially if the tripod is not really sturdy, but if possible I'd use faster speeds. Use a release cable, of course.
A slow film like the ADOX may be slow, and its definition may be not used fully unless the whole system is very stable, and the teleconverter may anyway reduce image quality a little. I'd choose between the Ektar 100 and the Portra 400 (or equivalent from other brands), to keep exposure above 1/125 at f/11, with the chosen filter.
Beware some filter will deliver a "white" image of the Sun, others may be designed to produce an "orange" one, and they are quite monochromatic. In the former case, a B/W film is a good choice also.
It's better to test the equipment and the exposure beforehand, taking some images of the Sun. A partial eclipse is as bright as the whole Sun - only until the Sun is about 90% covered there is a decrease of brightness.
