ZdenekP
Member
Dear all,
Maybe it is a silly question. Does a lens of a particular focal length demand a particular film speed?
Z.
Maybe it is a silly question. Does a lens of a particular focal length demand a particular film speed?
Z.
lZr
L&M
As far as we use RF cameras, I don't think the ISO must change as focal length is longer. How long? 135 mm? If you need open lens, than it must be taken into account for low light.
pvdhaar
Peter
In short, No.ZdenekP said:
You may be confused by the 1/focal length rule and the sunny 16 rule.
The 1/focal length rule says that you can handhold when the shutter speed is close to this or faster. For instance for your 135mm lens should be handholdable at 1/125 sec (or 1/250, 1/500 etc..)
The sunny 16 rule says that you get correct exposure outdoors in sunny conditions when the shutter speed is approximately 1/ISO and the aperture is F16. So, if you've 100 ISO film loaded, a 1/125shutter speed would be correct.
Combine the two, and you could end up with the impression that focal length and ISO are linked. But it's only under the condition that you want to shoot handheld, at F16, and outdoors in sunny weather..
wyk_penguin
Well-known
Yes, if you need to have control over the DOF and the shutter speed, i.e. handholding a 135mm and wanting to have a nice DOF at the same time. And yes, if you long lenses only come in f/8(more of a problem for SLR users which buy those inferior f/11 mirror lenses.
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