Why ISO80 ?

Dolby

Dolby

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Why do most (all?) camera's have a lowest setting of IS0 80?

If the lower, the less noise - why don't they give those the option of a (for example) ISO 40 for users that want to take a landscape on a tripod with no noise?
 
There are some MF digital cameras that go quite low, but it really has to do with the chip's base ISO. The base ISO of my camera is ISO200 (it can be set to 100). There is no noise at the base ISO. Why do you want ISO50? Is it because of your cameras slow flash sync? Mine only does 1/200th. Bummer!

PS 5D/II does ISO50 (the big Canons do 50, I think - is that right guys?)
 
To add to what ldmelsa said, it's pretty difficult to shoot in anything but bright sunlight at under 100 ISO. I have some Fuji Velvia 50 in one of my film bodies, and unless I have the tripod with me, I can really only use it for landscape stuff when the light is really good. With the G9, I can tell the difference between 80 and 100, so I don't think it makes a lot of sense to take the base ISO of those sensors even lower at the cost of their alredy questionable quality at high ISO
 
But if you could set the ISO really, really low, wouldn't you be able to get the same effects as using ND filters ?
(then again, it's easy enough to just get the filters)
 
ldmelsa said:
Why do you want ISO50? Is it because of your cameras slow flash sync? Mine only does 1/200th. Bummer!
Click to expand...

I don't *really* want it - but I'm learning all these photography concepts and that one made me curious ;)

See - m y understanding was lower ISO = less sensitive sensor = less noise. So I thought if you want to get a nice view and you had a tripod, it would be great to set it to sensitive, open the shutter (tripod) and get the best quality picture with no noise. As for the 2nd part of question, I haven't got to that concept yet - so I have no idea what you are talking about ;)
 
Dolby said:
As for the 2nd part of question, I haven't got to that concept yet - so I have no idea what you are talking about ;)
Click to expand...

If your camera's flash sync speed is slow it forces you to use smaller f-stops, to get the correct exposure for the ambient light. This can lead to diffraction and an undesirable f-stop. But if your camera can sync at a faster shutter speed you are able to use a larger f-stop, and thus less power from your flash. It is not only easier to balance with the ambient light, but better for freezing the action and allows for much faster flash recycle times (because you flash is using less power).
 
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