I am not in the path of totality so I will be photographing a partial. The Kodak guide says I can use 50 speed film, f/64, and 1/500 and be in the ballpark, then I don't need a solar filter at all. So why does everyone say you have to have a solar filter? Is the Kodak guide realistic?
Science is what we understand well enough to explain to a computer. Art is everything else we do.
--A=B by Petkovšek et. al.
Please folks, NEVER look at the sun through your camera without appropriate filtration.
First, (safety first) there are a great many IR wavelengths that are hazardous to your eyes normally, and focusing them with optics is worse, so you need to keep them out of the system (that someone will undoubtedly check visually to confirm it is aimed properly, etc), and 'ya don't want to view focused unfiltered sunlight!!!! Use a visual filter where light enters the optical system, and read the recent topic here about "My camera caught fire"...
Second, a limb of the sun is still as bright as the sun (just a smaller portion of it), and even with a solar filter there is still a lot of light passing through (that still produces a great deal of flare), so the filter helps cut the amount entering the system... A short exposure + the ND will limit the highlight produced brightness and will knock down the flare so the entire frame is not fogged over from overexposure + flare... (Fog level is high...) You should just be able to resolve a sunspot or two...
I suspect that exposures listed in the Kodak guides are assumed to be for amateurs that aim their normal FL cameras at the sun that day, and it is expected the sun will overexpose the film on that small dot, so a generous exposure is permitted, but enough to see the outlines of the moon, but working with much longer lenses or telescopes will concentrate more light to the frame and require less exposure, so at least exposure test your rig beforehand in sunlight to see how much less you need to expose, and figure that you have to control your highlights, also enough exposure to see the non backlit edges of the moon, so allow enough exposure for that, but also short enough to keep the fog level down... (Your film will be very reactive under these conditions...)
The older Kodak guides also mention an OK solar visual filter is a couple of fogged-out/developed-out pieces of film stacked together, but now a modern myth as thick emulsion films are gone and today's thin emulsions don't provide the protection they once had, so don't get any ideas about that!!!!
Be safe out there!!!
Steve K
I'm reading over this discussion and comments following my question of exposure during the eclipse totality - and I do plan to travel as close to the center of the path of totality as possible and I'm not anticipating any "limbs" leaking out during that 2 or so minute period, at least from the reading I've done from those who've experienced an eclipse like this.
Point is, it looks like I've culled enough general information about this question of exposure from the various reading and eclipse sites I've visited over the last day or two - - - I was really just hoping to hear someone who's actually done this before say something like, "400 speed film, 1/125 @ f11 worked for well for me", or somesuch thing to give me an idea of a reasonable point from which to bracket my exposures during this event.
/tldr Anyone think 1/125 @ f11 with HP5+ is a reasonable assumption for a good exposure of the eclipse?
Back in the late '80s, I experienced an eclipse. What still vividly remember is that the light seemed to be Polarized or at least, that is how everything around me looked. Very interesting.
Last edited by AtlantaTerry; 17-Aug-2017 at 23:37. Reason: Cleaning up my prose.
From my astrophotography days: when shooting a solar eclipse, bracket widely to capture everything from the Corona to the diamond ring. Do a Google search on exposure for solar eclipse, and you'll find very good resources that explain this. This isn't a new problem.
Newly made large format dry plates available! Look:
https://www.pictoriographica.com
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