AceAceBaby wrote:
I think ISO200 is mentioned in the article because that's the base ISO for the camera they were using. I also really don't see any benefit in exposing for 10 seconds or a minute to expose a lightning flash that lasted less than one second, only to catch it.
I remember years ago (possibly 25 or so, I am getting old) being told by numerous buffs and tutors that 200ISO is the best speed for flexibility in film, as in you could underdev the film to 50 or push it to 800 without there being a massive quality loss, whereas you couldn't do that with a slower film - well, you could push it, but it would fall apart quite badly after a couple of stops. While I think about it, a lot of films with titular speed differences that were offered by various manufacturers were actually the same film just processed slightly differently. Strangely enough, it seems as if Nikon are heading in this direction with their sensors, the holy grail to allow a sensor with enough flexibility to truly replicate an analogue camera and the possibility to put any film, as it were, AND more importantly, for it to behave similarly to film.
As for the lightning and shutter speed - it's very difficult to measure the actual luminance of the flash against the background without a very sophisticated spot meter, and that's the balance you're trying to get right, but the overall length of the exposure is more predicated by how dark it is, really as the lightning illumination is but a small focus bright light that only lasts for a split second. As I said earlier, it's probably best not to try and shoot at the dead of night as it's simply too dark to make it practicable to get decent results. The ideal time in this country, this time of year would probably be around 7:30pm to 8:30pm when the light is starting to fail, earlier if it's really overcast, natch.