Archived posting to the Leica Users Group, 1997/10/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 12:43 PM 10/16/97 +0800, you wrote: >> ... >> =A0=A0=A0=A0=A0The usual accepted figures are: >> =A0=A050mm lens ------ 1/25 =A0to 1/50 >> =A0=A090mm lens ------ 1/50 =A0to 1/100 >> =A0135mm " =A0=A0=A0=A0" =A0=A0=A0=A01/250 or faster >> =A0=A0=A0but this would be based on a particular circle of confusion of= =20 >> =A01/100" (I think). >> ... > >I agree with you on these figures. >I am not sure, but I think the circle of confusion just >decides the depth of field, which should have no direct >relation to the min. accepted shutter speed for steadiness. >However, it is very possible that the circle-of-confusion >blur (out-of-focus blur) can be analyzed mathematically/optically >to get the relation to the blur caused by camera/lens=20 >unsteadiness. Okay, you are mistaken. The 1/30 circle of confusion might not be the best way to put it, but the figure of 1/30 is how they define sharpness. And if you want to be able to distinguish objects that are 1/100 across, then you need the camera to be steadier than if you only want objects 1/30 or larger to be sharp. Does that make sense? =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Eric Welch St. Joseph, MO God is REAL, unless explicitly declared INTEGER.